MANIPULATOR HEAD AND VACUUM SYSTEM

Abstract

The invention relates to pumping liquids (18) in a vacuum system at a negative pressure, in particular at an absolute pressure of below 600 mbar. For this purpose, a manipulator head (10') is provided for use in a vacuum housing at a negative pressure. The manipulator head (10') contains a liquid cell (12) and a liquid pump (14). The liquid cell (12) has a liquid cell outlet (22) and an interior space (16) that is designed for negative pressure and designed to receive a liquid (18). The liquid pump (14) has a liquid pumping region (26) which is fluidically connected to the fluid cell outlet (22) and is designed to pump the liquid (18) out of the liquid pumping region (26) when there is negative pressure in the interior space (16) of the liquid cell (12). A distance (d') between the liquid cell outlet (22) of the liquid cell (12) and the liquid pumping region (26) of the liquid pump (14) is selected such that at an absolute pressure of below 600 mbar in the interior space (16) of the liquid cell (12), the liquid (18) extends at least as far as the liquid pumping region (26) of the liquid pump (14), so that the latter can pump the liquid (18). This makes it possible to construct a compact vacuum system that can circulate liquid (18) at an absolute pressure of below 600 mbar and in particular can also be drained.

Description

[0001] Manipulator head and vacuum system

[0002] FIELD OF THE INVENTION

[0003] The invention relates to a manipulator head for use in a vacuum housing under negative pressure, a manipulator with the manipulator head, a vacuum system with the manipulator head, a manufacturing method for the manipulator head, a method for operating the vacuum system, and uses of the vacuum system and the method for operating the vacuum system. In particular, the invention relates to filling and emptying an electrochemical cell at an absolute pressure of less than 600 mbar, for example, less than 400 mbar, in particular 100 mbar or less.

[0004] STATE OF THE ART

[0005] A vacuum system is known from the operating instructions V. 1.0 dated June 2, 2020 for the product O-EC-NAP Operando Electrochemical Cell from SPECS Surface Nano Analysis GmbH, in which an electrochemical cell is arranged in a vacuum housing in order to be able to carry out measurements on the electrochemical cell under negative pressure. The electrochemical cell is filled with a water-based electrolyte so that measurements can be carried out on a sample electrode as well as on the water-based electrolyte. In order to empty the electrochemical cell of the water-based electrolyte, a peristaltic pump is arranged outside the vacuum housing, which can pump the water-based electrolyte out of the electrochemical cell at absolute pressures above 600 mbar in the vacuum housing. For emptying, the absolute pressure in the vacuum housing is increased until the water-based electrolyte can be pumped out of the electrochemical cell.

[0006] WO 01 / 16486 A1 discloses a peristaltic pump with a pumping mechanism within a vacuum chamber. Placing the pumping mechanism within a vacuum chamber reduces the differential pressure between the inside and outside of the pumping channel, thereby minimizing changes in the enclosed fluid volume. DESCRIPTION OF THE INVENTION

[0007] It can be seen as an object of the invention to provide a manipulator head, a manipulator with the manipulator head and a vacuum system with the manipulator head, as well as a corresponding manufacturing method for the manipulator head and a method for operating the vacuum system with the manipulator head, which make it possible to pump liquid at an absolute pressure of less than 600 mbar.

[0008] According to a first aspect of the invention, a manipulator head is provided which is designed for use in a vacuum housing under negative pressure. The manipulator head comprises a liquid cell and a liquid pump. The liquid cell has a liquid cell outlet and an interior space designed for negative pressure, which is designed to receive a liquid. The liquid pump has a liquid pumping region fluidly connected to the liquid cell outlet and is designed to pump the liquid from the liquid pumping region under negative pressure in the interior space of the liquid cell.A distance between the liquid cell outlet of the liquid cell and the liquid pumping area of ​​the liquid pump is selected such that the liquid extends at an absolute pressure of less than 600 mbar, for example less than 400 mbar, in particular of 100 mbar or less, in the interior of the liquid cell at least into the liquid pumping area of ​​the liquid pump, so that the latter can pump the liquid.

[0009] Negative pressure is understood here as an absolute pressure that is below atmospheric pressure, i.e., a negative pressure is an absolute pressure less than atmospheric pressure, e.g., less than 1013.25 mbar or 1 atm. The negative pressure in the interior of the liquid cell can, for example, be an absolute pressure between 0.1 mbar and below 600 mbar. Preferably, the absolute pressure in the interior of the liquid cell can be between 0.1 mbar and 100 mbar.

[0010] The interior of the fluid cell can be fluidically connected to the environment of the manipulator head, i.e., gases and liquids can be exchanged between the interior of the fluid cell and the environment of the manipulator head. For this purpose, the fluid cell can, for example, have an opening to the environment of the manipulator head. This makes it possible, when the manipulator head is arranged in the vacuum housing, to adjust the pressure in the interior of the fluid cell via an operating pressure within the vacuum housing.

[0011] The manipulator head can, for example, be arranged in a vacuum housing of a vacuum system that operates close to the vapor pressure equilibrium of the liquid. This predetermines the pressure acting on the surface of the liquid, or the operating pressure, at a fixed temperature. At such a low operating pressure, in vacuum systems known from the prior art, the liquid cannot flow away due to the operating pressure alone, depending on other parameters such as the density of the liquid, the viscosity of the liquid, the inner diameter of a liquid line between the liquid line outlet and the liquid pumping area or the inner diameter of the liquid line for discharging the liquid, the material of the liquid line, the length of the liquid line, etc.If one wants to replace the fluid, the operating pressure in vacuum systems known from the state of the art would have to be increased, which would lead to an interruption of operation, for example a measurement.

[0012] In order for the liquid pump to pump the liquid, the liquid must extend into the liquid pumping area of ​​the liquid pump. The inventors have recognized that the operating pressure alone cannot ensure this if the distance between the liquid cell outlet of the liquid cell of the vacuum system known from the prior art is too great from the liquid pumping area of ​​the liquid pump. In this case, the pressure loss in a line between the liquid cell outlet and the liquid pumping area of ​​the liquid pump can be greater than the pressure forcing the liquid into the liquid pumping area.

[0013] Because the manipulator head incorporates both the fluid cell and the fluid pump, a compact design can be achieved, allowing for a shorter distance between the fluid cell outlet of the fluid cell and the fluid pumping area of ​​the fluid pump. This reduces the opposing forces that prevent the fluid from extending into the fluid pumping area of ​​the fluid pump. In particular, a pressure loss along a fluid line between the fluid cell outlet of the fluid cell and the fluid pumping area of ​​the fluid pump can be reduced if their distance is shorter, and thus the fluid line between the fluid cell outlet and the fluid pumping area is also shorter. The pressure loss is caused primarily by frictional forces between the fluid and the fluid line.A pressure loss along the liquid line can be reduced to such an extent that pumping of liquid by the liquid pump is possible even when the absolute pressure acting on the liquid is below 600 mbar, for example below 400 mbar, such as 100 mbar or less, in particular between 0.1 mbar and 100 mbar, e.g. between 10 mbar and 100 mbar. As a result, when the manipulator head and in particular the liquid cell are operating, the liquid can be pumped and thus exchanged at an absolute pressure of below 600 mbar, for example 100 mbar or less, without a higher pressure having to be generated in the vicinity of the manipulator head to enable pumping. This can also make it possible to empty the liquid cell.Since breaking the vacuum to replace the fluid is not necessary, the ingress of dirt into the area surrounding the manipulator head, and in particular into the fluid cell, can be prevented or at least reduced. This enables improved operation of the manipulator head. For example, even when the manipulator head, and in particular the fluid cell, is operating at vapor pressure equilibrium, the fluid can be pumped and, for example, replaced without increasing the pressure. Furthermore, measurement at a single location is possible at different fluid levels in the fluid cell, since fluid can be added to or removed from the fluid cell at the desired operating pressure.For example, when the manipulator head is used in a vacuum system with an illumination system and a detector system to analyze a sample, the sample can be analyzed in an unwetted state, a wetted state, and a state with a liquid film of different thickness on the surface of the sample without having to change the location on the sample to be measured.

[0014] Since the distance between the liquid cell outlet of the liquid cell and the liquid pumping area of ​​the liquid pump is selected such that the liquid extends at least into the liquid pumping area of ​​the liquid pump in the interior of the liquid cell at a negative pressure of less than 600 mbar, in particular of 100 mbar or less, the liquid can also be pumped for different liquids and different operating parameters of the liquid cell.

[0015] Extending into the liquid pumping area of ​​the liquid pump so that it can pump the liquid means that the liquid extends far enough into the liquid pump that pump elements can act to pump the liquid. For example, pump elements can be push-off elements, such as rollers or sliding shoes of a peristaltic pump. In this case, the liquid must extend far enough into the liquid pump that liquid can be pumped by pushing off a liquid line of the liquid pump using a push-off element and then moving the push-off element with the liquid line pushed off. In this case, the liquid pumping area begins behind the push-off position of the push-off element and the liquid must extend in the liquid line beyond the push-off position of the push-off element so that the liquid pump can pump the liquid.

[0016] If there is a negative pressure inside the fluid cell, the pressure acting on the fluid can be so low that the pressure loss along a fluid line between the fluid cell outlet of the fluid cell and the fluid pumping area of ​​the fluid pump is greater than the pressure pushing the fluid toward the fluid pumping area. In this case, the fluid cannot overcome the distance from the fluid cell outlet to the fluid pumping area, so the fluid cannot reach the fluid pumping area or at least does not extend far enough into the fluid pump for it to pump the fluid. In this case, fluid cannot be pumped out of the fluid cell to empty it.In other words, in this case, the pressure generated by the liquid column of a few centimeters—that is, a few mbar of hydrostatic pressure and, if necessary, a dynamic pressure due to the pumping of liquid into the interior—can be lower than the pressure loss along the liquid line. If the liquid line is shortened, beyond a certain length, the pressure loss becomes lower than the pressure acting on the liquid, so that the liquid extends into the liquid pumping area and can be pumped.

[0017] The pressure loss Ap 12 between a first position of the fluid line, for example a fluid line inlet, and a second position of the fluid line, for example the push-off position of the push-off element, can be determined, for example, based on the Darcy-Weisbach equation as Ap 12 P is the density of the Liquid, u is the flow velocity of the liquid, A is the pipe friction coefficient, l is the length of the liquid line between the first position and the second position and d is the liquid line inner diameter, as well as optionally a pressure loss coefficient for molded parts, such as bends or reducers. If the liquid line inner diameter and its material and the flow velocity are specified, e.g. due to design constraints, the pressure loss can be adjusted via the length of the liquid line. A liquid line volume can advantageously be minimized by choosing the liquid line inner diameter and the length of the liquid line as small as possible. This can, for example, make it possible to reduce a liquid dead volume, so that, for example, the flow time through the liquid line can be reduced, particularly when the liquid is replaced.Furthermore, the amount of liquid flowing through the liquid line can be reduced, so that operating costs can be reduced, especially for expensive liquids.

[0018] The total pressure p tot acting in a liquid line can be calculated for stationary flows of viscosity-free incompressible fluids using the Bernoulli pressure equation: Ptot = Pdyn + Pstat with the dynamic pressure p dyn = - - u and the static pressure p stat = p + p • g • h, which results from the operating pressure p and the hydrostatic pressure of the fluid column p g= p • g • h, where g is the acceleration due to gravity and h is the height of the liquid column. Furthermore, other pressures, for example due to the compressibility of the liquid, viscosity of the liquid and / or capillarity of the liquid line, can be taken into account in the Bemoulian pressure equation. Using the Bemoulian pressure equation and the Darcy-Weisbach equation, a maximum length of the liquid line can be estimated for which the total pressure is greater than the pressure loss and the distance between the liquid cell outlet and the liquid pumping area of ​​the liquid pump can be chosen accordingly so that the liquid extends into the liquid pumping area of ​​the liquid pump and the liquid can be pumped.

[0019] A person skilled in the art can determine the distance between the liquid cell outlet of the liquid cell and the liquid pumping area of ​​the liquid pump, for which the liquid extends into the liquid pumping area at an absolute pressure of less than 600 mbar, for example, through simple experimentation. For this purpose, for example, for liquid lines with identical liquid line inner diameters and different lengths, one can test which liquid lines the liquid extends into the liquid pumping area of ​​the liquid pump so that the liquid can be pumped. This makes it possible to take into account parameters of the vacuum system in which the manipulator head is arranged, such as the viscosity of the liquid, the liquid cell outlet diameter, the liquid line inner diameter, the liquid pumping area diameter, and other parameters.

[0020] The distance between the liquid cell outlet and the liquid pumping area can be a vertical distance, a horizontal distance, or a combination of vertical and horizontal distance. By providing a vertical distance between the liquid cell outlet and the liquid pumping area, an additional gravitational force acts on the liquid, so that additional pressure can be generated to push the liquid into the liquid pumping area. This can, for example, also make it possible to counteract adhesion forces. In other words, the provision of a vertical distance can generate a gravitational force on the liquid, so that even at an absolute pressure of less than 600 mbar, a positive force acts on the liquid, pushing the liquid into the liquid pumping area, so that adhesion forces of the liquid line can be overcome.

[0021] The liquid line can be formed from a material that is incompressible at atmospheric pressure. The material is considered incompressible if the inner diameter of the liquid line decreases by less than 5% when atmospheric pressure acts on the liquid line from the outside, if a negative pressure, for example of less than 600 mbar, in particular of 100 mbar or less, prevails within the liquid line. The material of the liquid line is preferably vacuum-compatible, chemically resistant, and inert. The material can, for example, contain or be steel or plastic, for example polyetheretherketone (PEEK) or polytetrafluoroethylene (PTFE). The liquid line can, for example, be a steel line whose inner wall is coated with a plastic, such as PEEK or PTFE.Alternatively, the fluid line can also be made of an elastic material so that it can be clamped off. The fluid line can be a PEEK tube, for example.

[0022] The fluid line can be designed such that it does not collapse when exposed to atmospheric pressure acting on the fluid line from the outside, or the fluid line's inner diameter decreases by less than 5% when an absolute pressure of, for example, less than 600 mbar, in particular 100 mbar or less, prevails within the fluid line. For this purpose, for example, a fluid line's inner diameter, an outer diameter, a fluid line's wall thickness, and the material properties of the fluid line can be coordinated accordingly.

[0023] The distance between the fluid cell outlet and the fluid pumping area can be, for example, between 0.1 mm and 200 mm, for example, between 0.1 mm and 100 mm, or between 1 mm and 40 mm. The fluid line can accordingly have a length between 0.1 mm and 200 mm, for example, between 0.1 mm and 100 mm, or between 1 mm and 40 mm.

[0024] The fluid line can have a constant inner diameter, for example, between 0.5 mm and 4 mm. This allows for a thin fluid line, allowing for a compact design of the manipulator head. Furthermore, a reduced volume for a lumen enclosed by the fluid line can be achieved. The inner diameter of the fluid line can be, for example, between 1 mm and 4 mm, such as 2 mm or 2.8 mm. A larger inner diameter of the fluid line also results in a larger outer diameter of the fluid line, so that a compact design is not possible with a large inner diameter of the fluid line. A smaller inner diameter of the fluid line can create capillary effects. The inner diameter of the fluid line can be selected so that forces created by capillary effects are small compared to other forces acting on the fluid.This can make it possible to reduce the adhesion forces in the fluid line.

[0025] The manipulator head can be an assembly of an interconnected fluid cell and fluid pump, which can be arranged together in a vacuum housing and attached to a manipulator, or arranged in the vacuum housing and attached to the manipulator. In particular, the manipulator head can be a manipulator head for a manipulator, i.e., the manipulator head can be suitable for connection to a manipulator, in particular for attachment to a manipulator.

[0026] The manipulator head may comprise a housing in which the fluid cell and the fluid pump are arranged. Alternatively, the fluid cell and the fluid pump may be arranged in separate, interconnected housings.

[0027] The manipulator head can have a fastening device designed to be attached to a manipulator. The fastening device can, for example, have a closure. The fastening device can also be just a surface with fastening means. For example, the fastening device can be a base of the manipulator head with threaded holes, which can be placed on a surface of the manipulator and into whose threaded holes screws that can be attached to the manipulator can be inserted to connect the manipulator head to the manipulator.

[0028] The liquid pump can also be connected directly to the liquid cell outlet, so that the distance between the liquid cell outlet and the liquid pumping area is very short, for example less than 1 mm, in particular 0.5 mm or less.

[0029] The fluid line does not have to end at the fluid pumping area of ​​the fluid pump. The fluid line can, for example, extend beyond the fluid pumping area of ​​the fluid pump, especially if the fluid pump is a peristaltic pump, where the fluid line runs through the peristaltic pump.

[0030] The liquid cell outlet and the liquid pumping region can be arranged relative to one another in such a way that, at a negative pressure of less than 600 mbar, in particular of 100 mbar or less, the liquid extends in the interior of the liquid cell solely by the action of gravitational force, at least into the liquid pumping region, so that the latter can pump the liquid.

[0031] The liquid cell outlet can be arranged in a bottom region of the liquid cell, in particular at a lowest point of the interior of the liquid cell. The liquid cell outlet of the liquid cell can be arranged at a vertical distance from the liquid pumping region of the liquid pump, which is selected such that, at an absolute pressure of less than 600 mbar, for example less than 400 mbar, in particular 100 mbar or less, the liquid extends in the interior of the liquid cell at least into the liquid pumping region of the liquid pump, so that the liquid can pump the liquid.

[0032] The bottom region can, for example, comprise the bottom of the liquid cell and / or a portion of the wall of the liquid cell, in particular a portion of the wall that is in contact with the bottom. The liquid cell outlet can be arranged at a lowest point of the interior of the liquid cell. For example, the liquid cell outlet can be arranged in the wall of the liquid cell such that a lowest point of the liquid cell outlet forms a lowest point of the interior of the liquid cell.

[0033] Because the liquid cell outlet of the liquid cell is located at the bottom of the liquid cell, particularly at the lowest point of the interior, the liquid can flow from the interior into the liquid cell outlet. Because the liquid cell outlet of the liquid cell is positioned at a vertical distance from the liquid pumping area of ​​the liquid pump, a gravitational force acts on the liquid between the liquid cell outlet of the liquid cell and the liquid pumping area of ​​the liquid pump. This gravitational force acts in the opposite direction to forces that prevent the liquid from penetrating into the liquid pumping area of ​​the liquid pump.Furthermore, since the vertical distance is selected such that the liquid extends at an absolute pressure of less than 600 mbar, in particular 100 mbar or less, within the interior of the liquid cell at least into the liquid pumping area of ​​the liquid pump, the liquid pump can pump the liquid. In other words, the vertical distance is selected such that the gravitational force is stronger than all opposing forces that prevent the liquid from extending into the liquid pumping area.

[0034] The vertical distance may, for example, be between 1 mm and 200 mm, for example between 1 mm and 40 mm, in particular between 5 mm and 20 mm, for example 12 mm.

[0035] A bottom of the liquid cell can have a slope toward the liquid cell outlet. The slope can be selected so that the liquid flows toward the liquid cell outlet. This allows the liquid to flow into the liquid cell outlet, thus improving the flow out of the liquid cell. The angle of the slope can be, for example, between 2° and 45° or between 2° and 20°. The liquid cell outlet can be located, for example, on one side of the liquid cell or in the center of the liquid cell.

[0036] The fluid pump can be a positive displacement pump, particularly a peristaltic pump. This allows for a simple design of the manipulator head.

[0037] The peristaltic pump can have a housing that encloses the liquid line. The liquid line can be arranged on a wall of the housing. The housing can have a rotor and one or more pressure-reducing elements, such as rollers or sliding shoes. The rotor can be connected to and drive these. The rollers or sliding shoes can be arranged such that they can pressure-reduce or clamp off a respective section of the liquid line as the rotor rotates, thereby pumping the liquid. The rollers can, for example, have lubricant-free hybrid ball bearings. If the liquid pump is provided in the form of a peristaltic pump, the liquid line is preferably a hose that can be clamped off the rollers or sliding shoes of the peristaltic pump.The provision of a liquid pump in the form of a peristaltic pump enables a simple and robust design in which the parts in contact with the liquid, in particular a liquid line in the form of a hose, are easily replaceable.

[0038] The liquid pump can also be or comprise, for example, a diaphragm pump, a piezo pump, an electroosmosis pump, or another type of positive displacement pump. The liquid pump can also be or comprise a microfluidic pump.

[0039] The liquid pump can have an inlet pressure of 0 mbar. The liquid pump can be made of one or more temperature-resistant materials, for example, temperature-resistant up to over 150°C or up to over 300°C, so that the liquid pump can be baked.

[0040] The liquid pump can be made of ultra-high vacuum (UHV) compatible materials. The materials can have a very low vapor pressure of, for example, less than 10' 10 mbar at 150°C to a magnitude of less than 10' 8 mbar at 130°C. The materials can be or contain stainless steel, aluminum, or PEEK, for example.

[0041] The liquid cell can be an electrochemical cell. The electrochemical cell can have a working electrode and a counter electrode. This allows the electrochemical cell to be operated at a vacuum of 600 mbar or less and to study its properties and behavior using a suitable analysis system. The working electrode can, for example, serve as a sample to be analyzed or measured. The liquid cell can have one or more additional electrodes, for example, a reference electrode.

[0042] The liquid can, for example, contain a liquid electrolyte, e.g. a water-based electrolyte, or be a liquid electrolyte, e.g. a water-based electrolyte. Alternatively, or additionally, the liquid can, for example, contain or be a water-based solution, an alcohol-based liquid, e.g. an alcohol such as glycol or ethanol, or an oil, such as motor oil, e.g. 5W40. The working electrode can be arranged in the electrochemical cell at an inclination to a liquid surface. The inclination can, for example, be between 0.1° and 80°, in particular between 15° and 45°. The inclination can be selected such that a first part of the working electrode protrudes from the liquid during operation, a second part of the working electrode is wetted by the liquid, and a third part of the working electrode can be located within the liquid.The working electrode can be arranged at a fixed inclination relative to a housing wall of the electrochemical cell, so that a fixed inclination to the liquid surface is established when the liquid cell is filled with the liquid. Alternatively, the working electrode can be arranged on an inclination device that can adjust an inclination angle of the working electrode relative to the housing wall of the electrochemical cell, so that an inclination angle to the liquid surface can also be adjusted. Alternatively, or additionally, the electrochemical cell can be inclined so that the working electrode has an inclination to the liquid surface. The electrochemical cell can be inclined, for example, using a manipulator.

[0043] Since the working electrode can be arranged with an inclination to the liquid surface in the electrochemical cell, various measurements can be performed with the working electrode, namely on the working electrode itself, on the working electrode when wetted by liquid, and on the liquid itself. Depending on the operation of the electrochemical cell, this may require little or no movement of the working electrode relative to a radiation spot or of the radiation spot relative to the working electrode.

[0044] The fluid cell may have a lid with an opening. The opening may be sized to ensure that the fluid in the fluid cell is fluidly connected to the environment of the manipulator head. For example, the opening may have an area between 1 mm 2 and 10 cm 2The opening can be oval, circular, or rectangular, for example. The lid prevents or at least reduces accidental leakage of liquid from the liquid cell into the area surrounding the manipulator head. The inner side of the lid, which faces the liquid, can be coated. For example, a coating made of PTFE or PEEK can be provided.

[0045] The inner wall of the fluid cell can be made of a plastic, such as PEEK. The inner wall of the fluid cell can also be coated with PTFE or made of PTFE.

[0046] The manipulator head can have a temperature control device. The temperature control device can contain one or more heaters and / or coolers. The temperature control device can be arranged on or in the fluid line, a fluid supply line, the fluid cell, and / or the fluid pump. This makes it possible to temperature control the fluid, i.e., to heat or cool it, in order to set a desired temperature for the fluid at a specific position of the manipulator head. Different heaters and coolers can also be provided at different positions of the manipulator head. This can make it possible to set different temperatures for the fluid at different positions of the manipulator head.

[0047] The manipulator head can have a buffer cell. The buffer cell can serve, for example, as a liquid reservoir, in particular as an electrolyte reservoir. The buffer cell can be arranged, for example, beneath the liquid cell. The buffer cell can be designed to collect liquid escaping from the liquid cell. For example, the buffer cell can be open at the top and have a larger base area than the liquid cell to collect liquid escaping from the liquid cell. This makes it possible to collect any unintentionally escaping liquid.

[0048] The buffer cell can be designed to serve as a vapor pressure buffer.

[0049] The temperature control device can further be designed to control the temperature of the buffer cell. One or more of the heaters and / or coolers of the temperature control device can, for example, be arranged on or in the buffer cell. This makes it possible, for example, to heat the buffer cell. This can, for example, make it possible to set a vapor pressure equilibrium between an electrolyte volume in the electrochemical cell and an electrolyte volume in the buffer cell if the liquid cell is an electrochemical cell and the liquid is an electrolyte. This can, for example, make it possible to keep an electrolyte level in the electrochemical cell constant. For this purpose, for example, a temperature of the buffer cell can be changed slowly or carefully in order to equalize the vapor pressure equilibrium between the electrochemical cell and the buffer cell if they are operated in a vacuum housing at negative pressure.

[0050] The manipulator head can have or be connected to one or more fluid reservoirs. The fluid reservoirs can, for example, be arranged in a cavity of the vacuum housing. This allows fluid to be pumped from the fluid reservoir into the fluid cell. For example, the fluid pump or another pump can be used to pump the fluid from the fluid reservoir into the fluid cell. The fluid reservoirs can serve as vapor pressure buffers.

[0051] The manipulator head can have a distance adjustment device configured to adjust the distance between the liquid cell and the liquid pump. The distance adjustment device can include or be a height adjustment device. The height adjustment device can be configured to adjust the vertical distance between the bottom of the liquid cell and the liquid pumping area of ​​the liquid pump.

[0052] Alternatively, the vertical distance can also be selected such that all fluids intended to be used during operation of the manipulator head at negative pressure extend at least into the fluid pumping area of ​​the fluid pump, so that they can be pumped by the pump. This ensures that the fluid extends into the fluid pumping area of ​​the fluid pump when the manipulator head is operating at an absolute pressure of less than 600 mbar, in particular 100 mbar or less, in the interior of the fluid cell. Therefore, the distance, and in particular the vertical distance, can be adapted to other operating conditions or parameters, such as the viscosity of the fluid and the internal diameter of the fluid line.

[0053] According to a further aspect of the invention, a manipulator is provided. The manipulator has a manipulator interior. The manipulator is designed to be hermetically connected to a vacuum housing. In particular, a cavity enclosed by the vacuum housing can be hermetically connected to the manipulator interior. The manipulator further comprises a movable shaft with a distal end. When the manipulator is connected to the vacuum housing, the distal end is movable in a cavity of the vacuum housing. The distal end of the movable shaft comprises the manipulator head according to at least one of claims 1 to 6 or an embodiment of the manipulator head. When the manipulator is connected to the vacuum housing, the manipulator head is therefore arranged in the cavity of the vacuum housing.This allows the manipulator head to be moved within a vacuum housing, for example, to prepare the fluid cell in a first position and analyze it or perform a measurement in a second position. For this purpose, the movable shaft can move the manipulator head from the first to the second position, for example, beneath an analysis system.

[0054] At least a portion of the movable shaft can be arranged in the manipulator interior. The manipulator can have a housing that encloses the manipulator interior. The housing can be, for example, a hollow cylinder. The manipulator interior can be a lumen. The movable shaft can be at least partially arranged in the lumen. The movable shaft can have a proximal end. When the manipulator is connected to the vacuum housing, the proximal end of the shaft can be arranged outside the vacuum housing, for example, in the lumen of the manipulator. The proximal end of the shaft can also form a proximal end of the manipulator and be arranged outside the lumen of the manipulator. The housing of the manipulator can have one or more accesses into the lumen. Lines can be guided through the manipulator through the lumen, and in particular in a shaft lumen enclosed by the movable shaft.The lines may, for example, include electrical lines and / or fluid lines. The access ports may, for example, be provided at or near the proximal end of the shaft.

[0055] The manipulator can be designed such that the distal end of the shaft can be moved within the vacuum housing and / or retracted behind a valve in the manipulator's interior. This allows a fluid cell located at the distal end of the shaft to be prepared with a sample at a first pressure and analyzed at a second pressure.

[0056] The movable shaft can also be rotatable. This can allow the manipulator head to be tilted.

[0057] For example, the shaft can have an outer diameter between 36 mm and 38 mm. The lumen in which the shaft is guided can have an inner diameter between 38 mm and 40 mm.

[0058] According to a further aspect of the invention, a vacuum system is provided, comprising: a vacuum housing for hermetically enclosing a first cavity during a vacuum and a manipulator head according to at least one of claims 1 to 6 or an embodiment of the manipulator head.

[0059] The manipulator head can be arranged in the first cavity of the vacuum housing. The vacuum system can be configured to generate an absolute pressure of less than 600 mbar, for example, less than 400 mbar, in particular 100 mbar or less, in the first cavity. The vacuum system can, for example, comprise one or more pumps to generate the negative pressure in the first cavity.

[0060] According to a further aspect of the invention, a vacuum system is provided, comprising: a vacuum housing for hermetically enclosing a first cavity during a vacuum and a manipulator according to claim 7 or an embodiment of the manipulator.

[0061] The manipulator can be hermetically connected to the vacuum housing. The manipulator head can be arranged in the first cavity of the vacuum housing. The vacuum system can be configured to generate an absolute pressure of less than 600 mbar, for example, less than 400 mbar, in particular 100 mbar or less, in the first cavity. The vacuum system can, for example, comprise one or more pumps to generate the negative pressure in the first cavity.

[0062] The vacuum system according to claim 8 or 9 or an embodiment of the vacuum system can comprise an illumination system and a detector system. The illumination system can be configured to illuminate the liquid cell with particles or radiation. The detector system can be configured to receive particles or radiation emitted from the liquid cell.

[0063] The illumination system may comprise a radiation source, for example, a radiation source for electromagnetic radiation such as X-rays, synchrotron radiation, deep ultraviolet (DUV) radiation, or light. The illumination system may additionally comprise a monochromator for spectrally isolating a specific wavelength from a beam incident from the radiation source. Alternatively, or additionally, the illumination system may also comprise a particle source. This makes it possible to provide particles or radiation that can be used to illuminate the fluid cell.

[0064] The illumination system can be movable and / or tiltable so that it can be moved towards the liquid cell or a sample located in the liquid cell in order to illuminate the liquid cell or the sample with the particles or radiation. Alternatively, or additionally, the detector system can be movable and / or tiltable so that it can be moved towards the liquid cell in order to receive particles or radiation emitted from the liquid cell. Alternatively, or additionally, the liquid cell can also be movable and / or tiltable, for example with the aid of the manipulator. The manipulator can enable the illumination system, the detector system, and the liquid cell to be moved and tilted relative to one another in such a way that measurement and / or analysis is possible. For example, the manipulator can move and tilt the liquid cell in the first cavity relative to the illumination system and the detector system.

[0065] The detector system can be designed to analyze the particles or radiation emitted from the liquid cell. The detector system can be a photoemission spectrometer, for example. The detector system can have a front cap electrode, one or more electronic lenses, one or more deflectors, an analyzer, and / or a detector. The detector system can be formed, for example, by the front cap electrode, the electronic lenses, the analyzer, and the detector. The detector system can have one or more interconnected cavities that form an interior of the detector system, through which particles or radiation emitted from the liquid cell can be guided from the front cap electrode to the detector. In addition, the detector system can also have one or more deflectors to direct the particles or radiation toward an input of the analyzer.

[0066] The front cap electrode can be conical in shape and have a tapered entrance opening, allowing gas molecules entering the entrance opening to quickly disperse behind the entrance opening into the cavity enclosed by the front cap electrode. This allows for rapid pressure reduction. This can increase the free path for electrons behind the entrance opening.

[0067] Different negative pressures can prevail in the several interconnected cavities, which can further decrease from the inlet opening towards the detector. For this purpose, different pressure reduction stages can be provided, and the pressure can be reduced to different degrees, for example, by means of pumps with different pumping powers in the successively arranged cavities. This can make it possible to maintain a lower pressure in the detector system. For example, in the case of an absolute pressure between 0.1 mbar and 100 mbar, e.g., 25 mbar, an absolute pressure in the range of 10 -4 mbar to 10 -2 mbar, e.g. 10 -3 mbar in the cavity enclosed by the front cap electrode, an absolute pressure of 10 -6 mbar to 10 -4 mbar, e.g. 10 -5 mbar in a subsequent cavity and an absolute pressure in the range of 10 -8 mbar to 10 -5mbar, e.g. 10 -6 mbar, in the cavity in front of the detector.

[0068] The analyzer can be, for example, a hemispherical energy analyzer or the analyzer can comprise one. The detector can comprise, for example, an electron multiplier, a phosphor screen, a video camera, a CCD (charge-coupled device) sensor, and / or a CMOS (complementary metal-oxide-semiconductor) sensor. The detector can also be designed as a DLD (delay line detector).

[0069] The inlet opening of the front cap electrode can, for example, be arranged above the liquid cell, in particular the opening in the lid of the liquid cell. The front cap electrode can, for example, also be introduced into the interior of the liquid cell through the opening in the lid of the liquid cell. This can make it possible to arrange the inlet opening of the front cap electrode directly above the working electrode serving as the sample. The opening in the lid of the liquid cell can be designed in such a way that it allows particles or radiation, for example X-rays, to radiate from the illumination system into the liquid cell and radiation or particles, for example electrons, to escape from the liquid cell through the opening.The lid of the liquid cell can make it possible to protect the inner walls of the liquid cell, especially if they are made of PEEK or coated with PEEK, from charging during photoemission experiments, for example.

[0070] An electron-transparent window can be provided in the opening. This can be formed, for example, by a single-layer membrane, such as single-layer carbon, or in other words, graphene. This can make it possible to set a different pressure in the vicinity of the manipulator head in the vacuum housing than the pressure inside the liquid cell.

[0071] The vacuum system may include a second cavity that is hermetically separated from the first cavity during operation. The first cavity may be configured for use with a different pressure range than the second cavity. This allows, for example, the liquid cell to be prepared for a measurement in the second cavity and a measurement to be performed in the first cavity.

[0072] The liquid may contain unwanted gases, for example oxygen (O2), carbon monoxide (CO), or carbon dioxide (CO2). The vacuum system may be designed to degas the liquid, for example, thermally. This may make it possible to prevent or at least reduce unintentional degassing of the liquid in the liquid cell. The vacuum system may, for example, be designed to carry out pressure degassing, vacuum degassing, membrane degassing, or chemical degassing. Degassing is preferably carried out outside the first cavity. This makes it possible to prevent or at least reduce the ingress of dirt into the first cavity and in particular into the liquid cell.

[0073] The vacuum system can have one or more fluid reservoirs for providing and / or collecting the fluid. The fluid reservoirs can be arranged in the first cavity or be fluidically connected to the first cavity. This can enable fluid exchange without having to break the vacuum. This can prevent or at least reduce the ingress of dirt into the first cavity and, in particular, into the fluid cell.

[0074] The vacuum system may include a potentiostat. The potentiostat may be connected to one or more of the electrodes of the electrochemical cell. This allows the electrical potential within the electrochemical cell to be changed.

[0075] The vacuum system may comprise a vacuum pump or be connected to a vacuum pump to generate a vacuum in the first cavity. The vacuum pump may be configured to generate a vacuum in the first cavity. The vacuum pump may, for example, be configured to generate an absolute pressure between 0.1 mbar and 600 mbar, between 0.1 mbar and 400 mbar, or between 1 mbar and 100 mbar, for example 20 mbar. This makes it possible to generate various pressures close to ambient pressure in the vacuum system, in particular close to atmospheric pressure, preferably close to the vapor pressure of the liquid used. The vacuum pump may, for example, be a diaphragm pump.

[0076] The first cavity can be filled with an inert gas. For example, the remaining air molecules in the first cavity can be replaced with inert gas molecules. The inert gas can, for example, contain or be a noble gas, such as argon, or a mixture of noble gases. The inert gas prevents chemical reactions between the inert gas and the liquid.

[0077] The vacuum housing can be made of stainless steel, for example. The vacuum housing can have one or more check valves to hermetically separate the first cavity from the environment of the vacuum housing.

[0078] The first cavity can, for example, have a volume between 0.0001 m 3 and 1 m 3 , such as between 0.001 m 3 and 0.1 m 3 , in particular a volume of 50 1.

[0079] The vacuum system may include a temperature control device. The temperature control device may contain one or more heaters and / or coolers. The temperature control device may be arranged on or in the liquid line, the movable shaft, a liquid supply line, the buffer cell, the liquid cell, and / or the liquid pump. This makes it possible to temperature control the liquid, i.e., to heat or cool it, in order to set a desired temperature for the liquid at a specific position in the vacuum system. Different heaters and coolers may also be provided at different positions in the vacuum system. This may make it possible to set different temperatures for the liquid at different positions in the vacuum system.

[0080] The temperature control device can have a temperature controller configured to prevent the liquid from boiling. The temperature controller can be connected to one or more sensors to detect various parameters, such as the pressure and temperature of the liquid and the liquid's environment. This can prevent the liquid from boiling, thus preventing the liquid from splashing out of the liquid cell and thus preventing the manipulator head and the first cavity from becoming contaminated with liquid. In particular, the temperature controller can reduce the vapor pressure and thus enable the liquid cell to operate at a lower pressure.

[0081] According to a further aspect of the invention, a method for manufacturing a manipulator head is provided. The method comprises the steps:

[0082] Providing a liquid cell having a liquid cell outlet and an interior space designed for negative pressure, which is designed to receive a liquid, providing a liquid pump having a liquid pumping region fluidly connected to the liquid cell outlet and which is designed to pump the liquid from the liquid pumping region when negative pressure exists in the interior of the liquid cell, and

[0083] Selecting a distance between the liquid cell outlet of the liquid cell and the liquid pumping area of ​​the liquid pump such that the liquid extends at an absolute pressure of less than 600 mbar, for example less than 400 mbar, in particular 100 mbar or less, in the interior of the liquid cell at least into the liquid pumping area of ​​the liquid pump so that the latter can pump the liquid.

[0084] The interior of the fluid cell may be provided such that it is fluidly connected to an environment of the manipulator head, for example by providing or providing an opening in the fluid cell to the environment of the manipulator head.

[0085] The liquid cell can be hermetically connected to the liquid pump.

[0086] In a further aspect, the invention also encompasses a method for manufacturing a vacuum system. The method for manufacturing a vacuum system includes, in addition to the steps for manufacturing a manipulator head, the following steps:

[0087] Providing a vacuum housing for hermetically enclosing a first cavity at a vacuum and

[0088] Providing the manipulator head in the first cavity.

[0089] The method for manufacturing a vacuum system may also include a step of providing a manipulator. Additionally, or alternatively, the method for manufacturing a vacuum system may also include the steps:

[0090] Providing an illumination system configured to illuminate the liquid cell with particles or radiation, and

[0091] Providing a detector system configured to receive particles or radiation emitted from the liquid cell.

[0092] According to a further aspect of the invention, a method for operating the vacuum system according to claim 10 or an embodiment of the vacuum system based on the vacuum system of claim 10 is provided. The method comprises the steps:

[0093] Generating an absolute pressure of less than 600 mbar, for example less than 400 mbar, in particular 100 mbar or less in the interior of the liquid cell, providing the liquid in the liquid cell, pumping the liquid from the liquid pumping area of ​​the liquid pump by means of the liquid pump so that the liquid is pumped out of the liquid cell,

[0094] Arranging the liquid cell, the illumination system and the detector system in such a way that the liquid cell can be illuminated with particles or radiation from the illumination system and radiation or particles can be received by the detector system,

[0095] Illuminating the fluid cell with particles or radiation from the illumination system and

[0096] Detecting radiation or particles emitted from the liquid cell in the detector system.

[0097] The negative pressure in the interior can be generated, for example, by generating negative pressure in the first cavity when the interior of the liquid cell is fluidly connected to the first cavity.

[0098] The provision of the liquid in the liquid cell and the pumping of the liquid from the liquid pumping area of ​​the liquid pump by means of the liquid pump can take place without the negative pressure having to be released. This allows the liquid to be exchanged during operation of the vacuum system. The liquid can be exchanged at a negative pressure, in particular at an absolute pressure of less than 600 mbar. The distance between the liquid cell outlet and the liquid pumping area can, for example, be selected such that the liquid extends at least as far as the liquid pumping area in the first cavity at an absolute pressure of less than 600 mbar, so that the liquid pump can pump the liquid.

[0099] The provision of the liquid in the liquid cell and the pumping of the liquid from the liquid pumping area by means of the liquid pump can, for example, be carried out continuously. This allows for continuous exchange of the liquid, for example, from a water-based electrolyte.

[0100] The method for operating the vacuum system may include one or more of the following steps:

[0101] Moving and / or tilting the liquid cell by means of the manipulator to arrange the liquid cell, the illumination system and the detector system relative to each other such that the liquid cell can be illuminated with particles or radiation from the illumination system and radiation or particles can be received by the detector system,

[0102] Providing the liquid in the liquid cell while pumping the liquid from the liquid pumping area of ​​the liquid pump,

[0103] Providing the liquid in the liquid cell and pumping the liquid from the liquid pumping area of ​​the liquid pump so that a certain liquid level is kept constant within the interior of the liquid cell,

[0104] Providing the liquid in the liquid cell and pumping the liquid from the liquid pumping area of ​​the liquid pump so that the liquid level within the interior of the liquid cell is changed,

[0105] Tilting the working electrode of the electrochemical cell so that a first part of the working electrode protrudes from the liquid during operation, a second part of the working electrode can be wetted by the liquid and a third part of the working electrode can be located within the liquid,

[0106] Providing the liquid in the electrochemical cell and pumping the liquid from the liquid pumping area of ​​the liquid pump such that a first part of the working electrode protrudes from the liquid during operation, a second part of the working electrode is wetted by the liquid and a third part of the working electrode is located within the liquid,

[0107] Illuminating the working electrode of the electrochemical cell with particles or radiation from the illumination system so that the first part of the working electrode, which protrudes from the liquid during operation, the second part of the working electrode, which is wetted by the liquid, and the third part of the working electrode, which is located within the liquid, are illuminated in succession.

[0108] The liquid may be provided in such a way as to avoid boiling over of the liquid, for example by pumping at a limited pumping speed and / or by pumping at a predetermined maximum pressure.

[0109] The method for operating the vacuum system may also comprise the steps of: providing the liquid in the liquid cell and pumping the liquid from the liquid pumping area of ​​the liquid pump such that the liquid level within the liquid cell changes continuously and

[0110] Illuminating the working electrode of the electrochemical cell with particles or radiation from the illumination system at a specific location on the working electrode while the liquid level within the liquid cell is continuously changing.

[0111] The continuous change may have a periodicity; for example, the liquid level may rise to a maximum liquid level, then fall to a maximum liquid level, and then rise again to the maximum liquid level. According to a further aspect of the invention, a use of the vacuum system according to claim 10 or an embodiment of the vacuum system based on the vacuum system of claim 10 is provided for: a surface analysis, a measurement of a surface reaction, a measurement of liquid-solid reactions, a measurement of liquid-gas reactions, a measurement of liquids, a measurement of thin layers, a detection of foreign substances in liquids, a photoemission measurement, a photoelectron spectroscopy measurement near atmospheric pressure, an X-ray photoelectron spectroscopy measurement near atmospheric pressure, an electrochemical measurement,a battery analysis, an oxidation measurement, an electrolyte measurement, an electrode measurement, a sample measurement through a liquid, a quality control, a corrosion measurement, a catalyst measurement, a pressure-dependent measurement, a measurement of a biological sample, a potentiometry measurement, a measurement of a supersaturated liquid.

[0112] Furthermore, according to a further aspect of the invention, a use of the method according to claim 12 or 13 or any embodiment of the method for operating the vacuum system according to claim 10 or an embodiment of the vacuum system based on the vacuum system of claim 10 is provided for: a surface analysis, a measurement of a surface reaction, a measurement of liquid-solid reactions, a measurement of liquid-gas reactions, a measurement of liquids, a measurement of thin layers, a detection of foreign substances in liquids, a photoemission measurement, a photoelectron spectroscopy measurement near atmospheric pressure, an X-ray photoelectron spectroscopy measurement near atmospheric pressure, an electrochemical measurement, a battery analysis, an oxidation measurement, an electrolyte measurement, an electrode measurement, a sample measurement through a liquid, a quality control,a corrosion measurement, a catalyst measurement, a pressure-dependent measurement, a measurement of a biological sample, a potentiometry measurement, a measurement of a supersaturated liquid.

[0113] According to a further aspect of the invention, a computer program product is provided for operating the vacuum system according to claim 10 or an embodiment of the vacuum system based on the vacuum system of claim 10. The computer program product includes computer program code means for causing a processor to execute the method according to claim 12 or 13 or any embodiment of the method when the computer program product is executed on the processor.

[0114] According to a further aspect, a computer-readable medium is provided having the computer program product stored thereon.

[0115] The manipulator head according to claim 1, the manipulator according to claim 7, the vacuum system according to claim 8, the vacuum system according to claim 9, the method according to claim 11, the method according to claim 13, the use according to claim 14, and the use according to claim 15 may have similar and / or identical preferred embodiments, as particularly defined in the dependent claims. Furthermore, a preferred embodiment of the invention may also be any combination of the features of the dependent claims or the aforementioned embodiments in conjunction with the corresponding independent claim.

[0116] These and other aspects of the invention are explained in more detail below with reference to embodiments shown in the figures.

[0117] SHORT DESCRIPTION OF THE CHARACTERS

[0118] In the following figures shows:

[0119] FIG 1 shows schematically and by way of example a first exemplary embodiment of the vacuum system in the form of a photoelectron spectroscopy system with a manipulator head attached to a manipulator according to a first exemplary embodiment with an electrochemical cell;

[0120] FIG 2 shows schematically and exemplarily a manipulator head according to a second embodiment;

[0121] FIG 3 shows schematically and by way of example a second embodiment of the vacuum system in the form of a photoelectron spectroscopy system with a manipulator head fastened in a vacuum housing according to a third embodiment;

[0122] FIG 4 shows schematically and exemplarily a manipulator head according to a fourth embodiment;

[0123] FIG 5 shows an exemplary flow diagram of an embodiment of the method for operating the vacuum system;

[0124] FIG 6 shows an exemplary flow diagram of an embodiment of a method for manufacturing the manipulator head.

[0125] DESCRIPTION OF THE EMBODIMENTS

[0126] The manipulator head described below using various exemplary embodiments and the exemplary embodiments of a vacuum system with the manipulator head, as well as the method for operating the vacuum system, make it possible to pump out liquids even at an absolute operating pressure of less than 600 mbar, for example less than 400 mbar, in particular 100 mbar or less, preferably in the range between 0.1 mbar and 100 mbar, e.g. between 10 mbar and 100 mbar. Thus, a liquid cell can be emptied as needed without increasing the operating pressure and the liquid in the liquid cell can be replaced. Furthermore, a liquid level can be changed without changing the operating pressure in the liquid cell. This makes it possible to carry out measurements at one point on a solid sample with different degrees of wetting of a liquid.Furthermore, the fluid can be continuously exchanged without changing the fluid level. This allows, for example, the fluid outside the fluid cell to be changed, the changed fluid introduced into the fluid cell, and the change in the fluid measured. Furthermore, it is possible to perform longer measurements if a fluid becomes depleted during the measurement, since the fluid can be refilled during the measurement without changing the measurement conditions.

[0127] FIG 1 shows a schematic and exemplary first embodiment of a vacuum system in the form of a photoelectron spectroscopy (PES) system 100. The PES system 100 can be used, for example, to perform measurements on a sample, e.g., a working electrode, and a liquid in the form of a water-based electrolyte at a pressure close to ambient pressure, in particular at an absolute pressure between 0.1 mbar and 100 mbar. Radiation is irradiated onto the sample and the liquid, and photoelectrons generated by the radiation are detected.

[0128] The PES system 100 includes a manipulator head 10, a vacuum pump 50, a manipulator 60, a vacuum housing 70 in the form of a vacuum chamber, an illumination system 80 in the form of a monochromatized aluminum (Al) X-ray source, and a detector system 90. Instead of an aluminum X-ray source, another X-ray source, for example a silver (Ag) or chromium (Cr) X-ray source or an X-ray source that provides multiple wavelengths, can be used.

[0129] The manipulator head 10 is designed for use in the vacuum housing 70 at negative pressures, for example, in the range between 0.1 mbar and 600 mbar. Materials specifically suited for such pressures are used to manufacture the manipulator head.

[0130] In this embodiment, the manipulator head 10 contains a fluid cell 12 in the form of an electrochemical cell and a fluid pump 14 in the form of a peristaltic pump (details not shown). Alternatively, a different type of fluid pump can be used, in particular a different type of positive displacement pump. Multiple fluid pumps can also be provided.

[0131] The liquid cell 12 has an interior space 16 designed for negative pressure, which is configured to hold a liquid 18 in the form of the water-based electrolyte. The interior space 16 is fluidically connected to the environment of the manipulator head 10 via an opening 19. In this exemplary embodiment, the liquid cell 12 has three electrodes 13, 15, and 17, namely a working electrode 13, a counter electrode 15, and a reference electrode 17. In other exemplary embodiments, a different number of electrodes can be provided, for example, 2 or 4. The liquid 18 can be introduced into the liquid cell 12 via a liquid cell inlet 20 and discharged from the liquid cell 12 again via a liquid cell outlet 22. In this exemplary embodiment, the liquid cell outlet 22 is arranged at a lowest point of the interior space 16 of the liquid cell 12, namely a lowest point of a base 24 of the liquid cell 12.In other embodiments, the liquid cell outlet can also be arranged, for example, in a different bottom region of the liquid cell, e.g., on a wall of the liquid cell with bottom contact. Furthermore, in this embodiment, the bottom 24 of the liquid cell 12 has an incline toward the liquid cell outlet 16 with an incline angle of 10°. In other embodiments, the bottom can also be designed without an incline or with a different incline, for example, an incline toward the liquid cell outlet with an incline angle between 2° and 20°, so that the liquid flows toward the liquid cell outlet and thus flows more effectively out of the liquid cell.

[0132] The liquid pump 14 has a liquid pumping region 26 that is fluidly connected to the liquid cell outlet 22. For this purpose, the liquid cell outlet 22 is connected to the liquid pumping region 26 via a liquid line 28 in the form of a PEEK tube. The liquid pump 14 is designed to pump the liquid 18 from the liquid pumping region 26 when there is negative pressure in the interior 16 of the liquid cell 12. In this exemplary embodiment, the liquid line 28 extends through the liquid pump 14 into a liquid reservoir 30, in which the pumped-out liquid 32 can be stored. For a better overview, the liquid line 28 is only partially shown within the liquid pump 14.The fluid pump 14 has rollers (not shown) that can pressurize the fluid line 28 within the fluid pump 14, so that by moving the rollers, the fluid 18 can be pumped section by section through the fluid line 28. The rollers can only pressurize the fluid line from a pressing position, which in this case marks the beginning of the fluid pumping area 26.

[0133] A distance d between the liquid cell outlet 22 of the liquid cell 12 and the liquid pumping region 26 of the liquid pump 14 is selected such that the liquid 18, at an absolute pressure in the range between 0.1 mbar and 100 mbar, extends in the interior 16 of the liquid cell 12 at least into the liquid pumping region 26, so that the liquid pump 14 can pump the liquid 18. In other words, the goal is to make the distance between the liquid cell outlet of the liquid cell and the liquid pumping region of the liquid pump so short that the pressure loss is smaller than the pressure difference existing between the liquid cell outlet and the liquid pumping region. In this exemplary embodiment, the distance d is a vertical distance. In other exemplary embodiments, the distance can also be composed of a vertical distance and a horizontal distance.In other embodiments, the distance between the liquid cell outlet and the liquid pumping region can also be selected such that the liquid extends at least into the liquid pumping region at an absolute pressure in the range of less than 600 mbar, for example less than 400 mbar, in particular 100 mbar or less, so that the liquid pump can pump the liquid.

[0134] In this embodiment, the liquid outlet 22 and the liquid line 28 have a constant inner diameter of 2.8 mm each. In other embodiments, the inner diameters can also be different, for example, between 1 mm and 4 mm, for example 2 mm. In further embodiments, the inner diameter of the liquid line can be adapted to an application, in particular to a viscosity of the liquid.

[0135] The distance d between the liquid cell outlet 22 and the liquid pumping region 26 is 12 mm in this embodiment. In this case, the length of a liquid line section between the liquid cell outlet 22 and the liquid pumping region 26 is also 12 mm. In other embodiments, the distance can also be, for example, between 1 mm and 200 mm.

[0136] The vacuum pump 50 can pump gas out of the vacuum housing 70, so that a negative pressure can be created in a first cavity 72 of the vacuum housing 70. In this case, the negative pressure is an absolute pressure between 0.1 mbar and 100 mbar, for example, 0.5 mbar, 1 mbar, or 2 mbar. In other embodiments, the negative pressure can be, for example, an absolute pressure below 600 mbar, below 400 mbar, or 100 mbar or less.

[0137] The manipulator 60 has a manipulator interior 62 and a movable shaft 64. The shaft 64 is also rotatable. The manipulator 60 is hermetically connected to the vacuum housing 70. The movable shaft 64 has a distal end 65 and a proximal end 66. The distal end 65 is arranged in the first cavity 72 of the vacuum housing 70, and the proximal end 66 is located outside the vacuum housing 70. A fluid supply line 67 runs from a fluid reservoir 69 through a lumen 63 extending through the movable shaft 64. A supply fluid 68 is stored in the fluid reservoir 69 and can be introduced into the fluid cell 12. For this purpose, the fluid supply line 67 is connected to the fluid cell 12 via the fluid cell inlet 20. The manipulator head 10 is attached to the distal end 65 of the movable shaft 64 of the manipulator 60.When the manipulator 60 is connected to the vacuum housing 70, the movable shaft 64 is movable and tiltable in the first cavity 72 of the vacuum housing 70, so that the manipulator head 10 is arranged in the first cavity 72 of the vacuum housing 70.

[0138] The illumination system 80 contains an X-ray source 82. In the X-ray source 82, an electron gun accelerates electrons toward an aluminum anode (not shown). The electrons striking the aluminum anode generate X-rays, which are monochromatized by the monochromator 84. The monochromatized X-rays X exit a monochromator outlet 86 and radiate onto the working electrode 13 to excite photoelectrons p. In other embodiments, the illumination system can also generate other radiation or particles and illuminate the liquid cell with them.

[0139] The photoelectrons p are analyzed in the detector system 90. For this purpose, the detector system 90 contains a front cap electrode 92, a lens system 94, a hemispherical energy analyzer 96, and a detector 98.

[0140] The front cap electrode 92 is as close as possible to the working electrode 13 of the liquid cell 12, for example, in the range of 0.2 mm to 0.5 mm, so that as many of the photoelectrons p emitted by the working electrode 13 of the liquid cell 12 as possible can enter an inlet opening of the front cap electrode 92 of the lens system 94. In this exemplary embodiment, the front cap electrode has a conical shape. This enables a rapid pressure reduction within the lens system 94. In addition, further vacuum pumps are provided which reduce the pressure within several consecutive cavities of the lens system 94 (not shown). This makes it possible to maintain an operating pressure of, for example, 0.1 mbar to 100 mbar in the first cavity 72, while in a cavity in front of the detector 98 only an absolute pressure of 10 -8 mbar to 10 -5 mbar, e.g. 10 -6mbar. This makes it possible to reduce the loss of photoelectrons due to collisions with gas molecules, thus improving signal quality.

[0141] The lens system 94 serves to transmit the photoelectrons p to the hemispherical energy analyzer 96 and to focus them so that the hemispherical energy analyzer 96 can separate the photoelectrons p according to their kinetic energies. For this purpose, the lens system 94 can contain various electron-optical lenses and / or deflectors (not shown). The photoelectrons p can then be detected by a detector 98. The detector 98 can be a CMOS detector, for example. The impact positions of the photoelectrons p measured by the detector 98 can then be assigned a corresponding kinetic energy in order to analyze the photoelectrons p.

[0142] In other embodiments, the detector system may also be configured to receive and analyze other particles or radiation emitted from the liquid cell.

[0143] FIG. 2 shows a schematic and exemplary manipulator head 10' according to a second exemplary embodiment. The manipulator head 10' contains a fluid cell 12 in the form of an electrochemical cell, a fluid pump 14 in the form of a peristaltic pump, a fastening device 34, a buffer cell 36, and a temperature control device 38. Components identical to other exemplary embodiments are designated by identical reference numerals.

[0144] The liquid cell 12 has a working electrode 13, a counter electrode 15, and a reference electrode 17. The working electrode 13 is arranged at an inclination relative to the liquid surface of the liquid 18 in the electrochemical cell 12. The inclination is selected such that a first part 23 of the working electrode 13 protrudes from the liquid 18, a second part 23' of the working electrode 13 is wetted by the liquid 18, and a third part 23" of the working electrode 13 is located within the liquid 18. In other embodiments, a relative angle of inclination of the working electrode to the liquid surface can also be changed using an inclination device. In another embodiment, for example, the entire liquid cell can be inclined such that the working electrode is inclined relative to the liquid surface.The manipulator head and thus also the liquid cell can, for example, be tilted by a manipulator by rotating its movable shaft by a certain angle.

[0145] Furthermore, the liquid cell 12 has an opening 19 that connects an interior space 16 of the liquid cell 12 with the environment. The working electrode 13 is arranged below the opening 19 so that a detector system can be moved toward the working electrode 13, or the working electrode 13 can be moved toward the detector system.

[0146] The liquid cell 12 has a liquid cell inlet 20 for introducing the liquid 18 and a liquid cell outlet 22 for discharging the liquid 18 from the liquid cell 12. In this exemplary embodiment, the base 24 is also provided with an incline so that the liquid 18 flows towards the liquid cell outlet 22. In this exemplary embodiment, the liquid pump 14 is directly connected to the liquid cell outlet 22. In this case, the distance d' between the liquid cell outlet 22 and the liquid pumping region corresponds to a wall thickness of the housing part that forms the liquid cell outlet 22 and a short liquid line region before a push-off position at which the liquid pumping region 26 begins. In this case, the distance d' is, for example, 1 mm. The fastening device 34 can be attached to a manipulator.In this embodiment, the fastening device 34 contains a threaded bore 35 into which a screw can be screwed in order to fasten the manipulator head 10 to a shaft of a manipulator.

[0147] The buffer cell 36 is open at the top so that liquid 18 splashing down from the liquid cell 12 can be collected in the buffer cell 36.

[0148] The temperature control device 38 is arranged between the liquid cell 12 and the buffer cell 36 and contains heating and cooling means to control the temperature of the liquid cell 12 and the buffer cell 36.

[0149] FIG. 3 schematically and exemplarily shows a second embodiment of the vacuum system in the form of a PES system 100. The PES system 100 is similar to the PES system 100 shown in FIG. 1. Identical reference numerals are used for identical components in the other embodiments, and for a description of the function of these components, reference is made to the description of FIG. 1.

[0150] The PES system 100" includes a manipulator head 10", a vacuum pump 50, a vacuum housing 70 in the form of a vacuum chamber, an illumination system 80 in the form of a monochromatized Al X-ray source, and a detector system 90.

[0151] In contrast to the PES system 100, the manipulator head 10" in the PES system 100" is mounted in the vacuum housing 70 and not at the distal end of a manipulator. Therefore, in this exemplary embodiment, the manipulator head 10" cannot be moved with the manipulator. In order to align the illumination system 80 and the detector system 90 with the working electrode 13 of the liquid cell 12" of the manipulator head 10", the illumination system 80 and the detector system 90 must be moved accordingly and tilted if necessary in this exemplary embodiment. Appropriate actuators (not shown) are provided for this purpose. Alternatively, one or more deflectors can also be provided, for example, which can align the beam or particles from the illumination system with the working electrode (not shown).Furthermore, in this embodiment, the first liquid reservoir 69 is also located within the vacuum housing 70, so that the liquid supply line 67 also runs completely within the first cavity 72 of the vacuum housing 70.

[0152] The manipulator head 10" contains the fluid cell 12" and the fluid pump 14", which are connected to each other via a fluid line 28".

[0153] The liquid cell outlet 22" of the liquid cell 12" is arranged in the bottom area on a wall of the liquid cell 12". The distance d" of the liquid cell outlet 22" of the liquid cell 12" to the liquid pump area 26" of the liquid pump 14" is made up of the horizontal distances d1 and d2 and the vertical distance h" in this embodiment. Due to the vertical distance h", an additional hydrostatic pressure acts through the liquid column of the liquid 18. The distance d" is selected such that the acting pressure is greater than the pressure loss between the liquid cell outlet 22" and the liquid pump area 26", in particular along the liquid line 28", so that the liquid 18 extends into the liquid pump area 26" and the liquid pump 14" can pump the liquid 18.

[0154] FIG 4 shows schematically and exemplarily a manipulator head 10'' according to a fourth embodiment.

[0155] The manipulator head 10'" contains a fluid cell 12'" and a fluid pump 14'". In this embodiment, the fluid cell 12'" and the fluid pump 14" are arranged in a common housing.

[0156] The housing contains an opening 19, which is separated from the surroundings of the manipulator head 10'" by a transparent window 40 in the form of a layer of graphene. This prevents liquid 18 from escaping through the opening 19. Furthermore, it allows a different pressure to be set in the surroundings of the manipulator head 10'" and within the interior space 16'". For example, a higher pressure can prevail in the liquid cell 12" than in the surroundings of the manipulator head 10'". Alternatively, another transparent window can be provided that is transparent to the radiation and particles radiating in from the illumination system and emitted from the liquid cell 12". Transparent here does not mean that there must be no losses in the transparent window, but rather that the transmission is relatively high, for example, over 90%.Furthermore, instead of a single opening, several openings with several transparent windows can be provided, for example, one opening for the radiation or particles radiating into the liquid cell and one opening for particles or radiation emitted from the liquid cell. In this case, the transparent windows can also be formed from different materials, each of which is transparent to the radiation or particles passing through them.

[0157] The liquid cell 12" ' contains an inclined working electrode 13 and a counter electrode 15. Liquid 18 is introduced via the liquid cell inlet 20 into the interior 16'" of the liquid cell 12'" and is introduced via the liquid cell outlet 22'" from the liquid cell 12'" into the liquid pumping region 26'" of the liquid pump 14'". A bottom 24 with an incline ensures that the liquid 18 flows into the liquid cell outlet 22" '. The distance d"' between the liquid cell outlet 22'" of the liquid cell 12'" and the liquid pumping area 26'" of the liquid pump 14"' is a horizontal distance in this case. The distance d"' is selected such that the liquid 18 extends into the liquid pumping area 26"' and the liquid pump 14"' can pump the liquid 18.

[0158] In other embodiments, the liquid cell can also be tilted to allow the liquid to flow into the liquid cell outlet. In this case, the liquid cell outlet can also be located on a wall of the liquid cell, in particular without contact with the bottom. Preferably, the liquid cell outlet is arranged in the wall such that, when the liquid cell is tilted, the liquid cell outlet is located at the lowest point of the interior of the liquid cell, so that the liquid flows out of it. In this case, the inclination can be selected such that the working electrode is aligned with the illumination system and the detector system, allowing a measurement to be performed.

[0159] FIG. 5 shows an exemplary flowchart of an embodiment of a method 500 for operating a vacuum system. For example, the vacuum system shown in FIG. 1 or FIG. 3 can be operated according to the method.

[0160] In step 502, an absolute pressure between 0.1 mbar and 100 mbar, for example, 25 mbar, is generated in the interior of the liquid cell. For this purpose, the vacuum pump is used to pump gas out of the first cavity of the vacuum housing, which is fluidly connected to the interior of the liquid cell. In other embodiments, an absolute pressure of, for example, less than 600 mbar, less than 400 mbar, or 100 mbar or less, for example, from 1 mbar to less than 600 mbar, from 1 mbar to less than 400 mbar, or from 1 mbar to 100 mbar, can also be generated in the interior of the liquid cell.

[0161] In step 504, the liquid is provided in the liquid cell. For this purpose, the liquid is introduced into the liquid cell via the liquid cell inlet. This liquid extends into the liquid pumping area of ​​the liquid pump, allowing the liquid pump to pump the liquid to circulate the liquid or to empty the liquid cell.

[0162] In step 506, the liquid is pumped from the liquid pumping area of ​​the liquid pump by the liquid pump, thereby pumping the liquid out of the liquid cell. Since, in this embodiment, liquid is simultaneously supplied to the liquid cell via the liquid cell inlet, a continuous exchange of liquid can take place. In other words, in this embodiment, steps 504 and 506 are performed such that a specific liquid level is maintained constant within the interior of the liquid cell.

[0163] In other embodiments, the liquid in the liquid cell can also be provided and the liquid pumped from the liquid pumping area of ​​the liquid pump in such a way that the liquid level within the interior of the liquid cell changes, for example, continuously and / or periodically. This can make it possible to perform measurements at different liquid levels at one measuring point.

[0164] In alternative embodiments, the liquid cell can also be emptied, for example, after a measurement in order to fill it with another liquid.

[0165] In step 508, the liquid cell, the illumination system, and the detector system are arranged relative to one another such that the liquid cell can be illuminated with the X-ray radiation from the illumination system and the photoelectrons can be received by the detector system. In other embodiments, other radiation or particles can be provided by the illumination system, and the detector system can detect other particles or radiation.

[0166] In the case of the PES system shown in FIG 1, the liquid cell is moved and tilted accordingly with the aid of the manipulator so that a radiation spot of the illumination system is aligned with a point to be measured on the working electrode of the liquid cell and an entrance opening into the detector system is located above the radiation spot so that the photoelectrons can enter it.

[0167] In other embodiments, for example in the case of the PES system shown in FIG 3, the illumination system and the detector system can be moved and tilted such that a radiation spot of the illumination system is aligned with a point to be measured on the working electrode of the liquid cell and an entrance opening into the detector system is located above the radiation spot so that the photoelectrons can enter it.

[0168] In step 510, the liquid cell or the location to be measured on the working electrode of the liquid cell is illuminated with X-rays from the illumination system. This generates photoelectrons that enter the detector system. To generate the highest possible number of photoelectrons that can enter the detector system, various parameters of the illumination system can be optimized.

[0169] In other embodiments, the liquid cell may also be irradiated with other radiation or particles to generate radiation or particles.

[0170] Instead of the working electrode, another electrode of the liquid cell can be irradiated, or the liquid itself, or the working electrode wetted with liquid. For example, the working electrode can be tilted so that the liquid creates a meniscus on the surface of the working electrode, allowing the working electrode measurement to be performed through a thin film of liquid.

[0171] The working electrode can also be tilted so that a first part of the working electrode protrudes from the liquid, a second part of the working electrode is wetted by the liquid, and a third part of the working electrode is located within the liquid. The liquid can also be provided in the electrochemical cell and the liquid pumped from the liquid pumping area of ​​the liquid pump such that a first part of the working electrode protrudes from the liquid during operation, a second part of the working electrode is wetted by the liquid, and a third part of the working electrode is located within the liquid.In this case, for example, the working electrode can be illuminated with particles or radiation from the illumination system in such a way that the first part of the working electrode, which protrudes from the liquid, the second part of the working electrode, which is wetted by the liquid, and the third part of the working electrode, which is located within the liquid, are illuminated one after the other. For this purpose, the spot can be moved on the working electrode. Alternatively, the liquid can be pumped in such a way that the liquid level changes, allowing measurements with and without a liquid film on the working electrode to be performed consecutively at the same measuring point, for example, by raising the liquid level in the liquid cell.

[0172] In step 512, the photoelectrons emitted from the liquid cell or from the point of the liquid cell's working electrode to be measured are detected in the detector system. To detect the photoelectrons in the detector system, various parameters of the detector system can be optimized.

[0173] In other embodiments, other particles or radiation may also be detected in the detector system.

[0174] The vacuum systems 100 and 100' shown in FIGS. 1 and 3, as well as the method shown in FIG. 5, can be used, for example, for a surface analysis, a measurement of a surface reaction, a measurement of liquid-solid reactions, a measurement of liquid-gas reactions, a measurement of liquids, a measurement of thin layers, a detection of foreign substances in liquids, a photoemission measurement, a photoelectron spectroscopy measurement near atmospheric pressure, an X-ray photoelectron spectroscopy measurement near atmospheric pressure, an electrochemical measurement, a battery analysis, an oxidation measurement, an electrolyte measurement, an electrode measurement, a sample measurement through a liquid, a quality control, a corrosion measurement, a catalyst measurement, a pressure-dependent measurement, a measurement of a biological sample, a potentiometry measurement,and / or a measurement of a supersaturated liquid.,

[0175] FIG. 6 shows an exemplary flowchart of an embodiment of a method 600 for manufacturing the manipulator head. For example, one of the embodiments of the manipulator head 10, 10', 10", or 10'" shown in FIGS. 1, 2, 3, and 4 can be manufactured.

[0176] In step 602, a liquid cell in the form of an electrochemical cell is provided. For this purpose, a housing is provided with four side walls and a base, which enclose an interior space that can accommodate a liquid, in particular a water-based electrolyte. The housing also has a lid with an opening. The housing is suitable for operation in a negative pressure, in particular at an absolute pressure of below 600 mbar, for example, an absolute pressure of 100 mbar or less. Optionally, several electrodes can be provided in the liquid cell, for example, a working electrode, a reference electrode, and a counter electrode.

[0177] Furthermore, the liquid cell has a liquid cell inlet for introducing liquid into the liquid cell and a liquid cell outlet for removing liquid from the liquid cell. In this embodiment, the liquid cell outlet is located in the base of the liquid cell at a lowest point of the base, so that it can serve as an outlet for the liquid, similar to a bathtub outlet. This allows the liquid cell to be completely emptied. Optionally, the base is inclined toward the liquid cell outlet, for example, at an angle of 10°.

[0178] Since at an absolute pressure of less than 600 mbar the liquid would not flow through a liquid line on its own - depending on the liquid line inner diameter, viscosity of the liquid and length of the liquid line - a liquid pump must also be provided to pump out the liquid.

[0179] In step 604, a liquid pump in the form of a peristaltic pump is provided. The liquid pump has a liquid pumping region. In this embodiment, the liquid pumping region is formed by a portion of a liquid line in the form of an elastic PEEK tube. In this embodiment, the liquid pumping region extends from a first pressing point of a roller of the liquid pump to a second point corresponding to a distance between the rollers, so that when the roller presses the tube, liquid is transported along the tube by the movement of the roller. In other words, the liquid pump can pump the liquid that extends into the liquid pumping region of the liquid pump.

[0180] In step 606, a distance between the liquid cell outlet of the liquid cell and the liquid pumping region of the liquid pump is selected such that, at an absolute pressure between 1 mbar and 100 mbar, the liquid extends at least into the liquid pumping region in the interior of the liquid cell, so that the liquid pump can pump the liquid. This ensures that the liquid can be pumped out of the liquid pumping region. In other embodiments, the distance between the liquid cell outlet and the liquid pumping region can also be selected such that, at an absolute pressure of less than 600 mbar, less than 400 mbar, or 100 mbar or less, the liquid extends at least into the liquid pumping region in the interior of the liquid cell, so that the liquid pump can pump the liquid.

[0181] The distance can be composed of a vertical and a horizontal distance. For example, for fixed parameters such as the inner diameter of the fluid line, the material of the fluid line, the desired absolute pressure inside the fluid cell, and the viscosity of the fluid, the distance between the fluid cell outlet and the fluid pumping area can be reduced until the fluid pump can pump the fluid. For example, the length of the fluid line between the fluid cell outlet and the fluid pumping area can be reduced until fluid can be pumped. This can be done experimentally or calculated, for example, by simulation or based on the Bernoulli equation.

[0182] The above description of the invention, in conjunction with the drawings, serves to illustrate the features of the invention by way of example in the form of exemplary embodiments. However, the features explained in the exemplary embodiments are only exemplary and should not be understood as limiting. In particular, the invention is not limited to the exemplary embodiments or the combination of features of individual exemplary embodiments. For example, it is also possible to operate the invention in an exemplary embodiment with a different illumination system, for example, with a synchrotron radiation source or a different detector system.

[0183] Other variants and variations of the embodiments shown can be understood and implemented by those skilled in the art by reworking the claimed invention in view of the figures, description and claims.

[0184] The words “contain”, “comprise”, “include” do not exclude further elements, components or steps and the indefinite articles “a” or “an” do not exclude a plurality.

[0185] The fact that certain means are mentioned in different claims should not be understood as meaning that a combination of these means cannot be used advantageously.

[0186] The reference numerals used in the claims are not to be understood as limiting the features of the embodiments, but merely as examples of the features of the claims.

[0187] The invention relates to pumping liquids in a vacuum system at a negative pressure, in particular at an absolute pressure of less than 600 mbar. For this purpose, a manipulator head is provided for use in a vacuum housing at a negative pressure. The manipulator head contains a liquid cell and a liquid pump. The liquid cell has a liquid cell outlet and an interior space designed for negative pressure, which is configured to receive a liquid. The liquid pump has a liquid pumping region fluidly connected to the liquid cell outlet and is designed to pump the liquid from the liquid pumping region at a negative pressure in the interior of the liquid cell.The distance between the fluid cell outlet and the fluid pumping area of ​​the fluid pump is selected such that, at an absolute pressure of less than 600 mbar, the fluid extends at least into the fluid pumping area of ​​the fluid pump, allowing the fluid to be pumped. This enables a compact design for a vacuum system that can circulate fluid at an absolute pressure of less than 600 mbar and, in particular, can also be drained.

Claims

REQUIREMENTS:

1. Manipulator head (10; 10'; 10"; 10" '), wherein the manipulator head (10; ... ; 10" ') is configured for use in a vacuum housing (70) under vacuum and comprises: a liquid cell (12; 12"; 12" ') with a liquid cell outlet (22; 22"; 22'") and a vacuum-configured interior (16) configured to receive a liquid (18), and a liquid pump (14; 14"; 14" ') comprising a fluid-connected liquid pumping area (26; 26"; 26" ') to the liquid cell outlet (22; 22"; 22'") and designed to pump the liquid (18) from the liquid pumping area (26; 26"; 26'") under vacuum in the interior (16) of the A fluid cell (12; 12"; 12'") is formed, wherein a distance (d; d'; d"; d"') is formed between the fluid cell outlet (22; 22"; 22'“) of the liquid cell (12; 12“; 12'“) and the liquid pumping area (26; 26“; 26'“) of the liquid pump (14; 14“; 14'“) is selected such that the liquid (18) extends at least as far as the liquid pumping area (26; 26“; 26'“) of the liquid pump (14; 14“; 14'“) at an absolute pressure of less than 600 mbar, preferably less than 400 mbar, in particular 100 mbar or less, within the interior (16) of the liquid cell (12; 12“; 12'“), so that the latter can pump the liquid (18).

2. Manipulator head (10; 10'; 10") according to claim 1, wherein the liquid cell outlet (22; 22") is arranged in a bottom region of the liquid cell (12; 12"), in particular at a lowest point of the interior (16) of the liquid cell (12; 12"), and wherein the liquid cell outlet (22; 22") of the liquid cell (12; 12") is arranged to the liquid pumping section (26; 26") of the liquid pump (14; 14") at a vertical distance (d; d'; h") which is selected such that the liquid (18) at an absolute pressure of less than 600 mbar, preferably less than 400 mbar, in particular 100 mbar or less, in the interior (16) of the liquid cell (12; 12") at least as far as the liquid pumping section (26; 26") of the liquid pump. (14; 14") extends so that it can pump the liquid (18).

3. Manipulator head (10; ... ; 10“ ') according to claim 1 or 2, wherein a bottom of the liquid cell (12; 12“; 12“ ') has an inclination towards the liquid cell outlet (22; 22“; 22'“) and wherein the inclination is selected such that the liquid (18) flows towards the liquid cell outlet (22; 22“; 22“ ').

4. Manipulator head (10; 10'") according to at least one of claims 1 to 3, wherein the liquid pump (14; 14"; 14'") comprises a positive displacement pump, in particular a peristaltic pump.

5. Manipulator head (10; ... ; 10“ ') according to at least one of claims 1 to 4, wherein the liquid cell (12; 12“; 12'“) is an electrochemical cell comprising a working electrode (13) and a counter electrode (15).

6. Manipulator head (10; ... ; 10'“) according to claim 5, wherein the working electrode (13) is arranged with an inclination towards a liquid surface in the electrochemical cell (12; 12“; 12“ ') which is selected such that a first part (23) of the working electrode (13) can protrude from the liquid (18) during operation, a second part (23') of the working electrode (13) can be wetted by the liquid (18) and a third part (23“) of the working electrode (13) can be located within the liquid (18).

7. Manipulator (60) with a manipulator interior (62) configured to be hermetically connected to a vacuum housing (70), wherein the manipulator (60) has a movable shaft (64) with a distal end (65) which, in a state of the manipulator (60) connected to the vacuum housing (70), is movable in a cavity (72) of the vacuum housing (70), wherein the distal end (65) of the movable shaft (64) has the manipulator head (10) according to at least one of claims 1 to 6, such that the manipulator head (10) is arranged in the cavity (72) of the vacuum housing (70) in a state of the manipulator (60) connected to the vacuum housing (70).

8. Vacuum system (100; 100"), comprising: a vacuum housing (70) for hermetically enclosing a first cavity (72) under vacuum and a manipulator head (10; ... ; 10" ') according to at least one of claims 1 to 6.

9. Vacuum system (100) comprising: a vacuum housing (70) for hermetically enclosing a first cavity (72) under vacuum and a manipulator (60) according to claim 7.

10. Vacuum system (100; 100") according to claim 8 or 9, comprising: a lighting system (80) configured to illuminate the liquid cell (12; 12"; 12" ') with particles or radiation (X) and a detector system (90) configured to receive particles (p) or radiation emitted from the liquid cell (12; 12"; 12" ').

11. Method for manufacturing a manipulator head (600), comprising the steps: Providing a liquid cell with a liquid cell outlet and a negative pressure interior designed to receive a liquid (602), Providing a liquid pump which has a fluid-connected liquid pumping area connected to the liquid cell outlet and which is designed to pump the liquid from the liquid pumping area under negative pressure inside the liquid cell (604), and Selecting a distance between the liquid cell outlet of the liquid cell and the liquid pumping area of ​​the liquid pump such that the liquid extends inside the liquid cell at least as far as the liquid pumping area of ​​the liquid pump at an absolute pressure of less than 600 mbar, preferably less than 400 mbar, particularly less than 100 mbar or less, so that the pump can pump the liquid (606).

12. Method for operating the vacuum system (500) according to claim 10, comprising the steps: Generating an absolute pressure of less than 600 mbar, preferably less than 400 mbar, in particular 100 mbar or less, inside the liquid cell (502), providing the liquid in the liquid cell (504), pumping the liquid from the liquid pumping area of ​​the liquid pump by means of the liquid pump, so that the liquid is pumped out of the liquid cell (506), Arranging the liquid cell, the illumination system and the detector system in such a way that the liquid cell can be illuminated with particles or radiation from the illumination system and radiation or particles can be received by the detector system (508), Illuminating the liquid cell with particles or radiation from the lighting system (510) and Detecting radiation or particles emanating from the Liquid cell were released into the detector system (512).

13. The method according to claim 12, comprising one or more of the steps: Methods and / or tilting of the liquid cell by means of the manipulator to arrange the liquid cell, the illumination system and the detector system in such a way that the liquid cell can be illuminated with particles or radiation from the illumination system and radiation or particles can be received by the detector system, Providing the liquid in the liquid cell while pumping the liquid from the liquid pumping area of ​​the liquid pump, Providing the liquid in the liquid cell and pumping the liquid from the liquid pumping area of ​​the liquid pump so that a certain liquid level is kept constant inside the liquid cell, Providing the liquid in the liquid cell and pumping the liquid from the liquid pumping area of ​​the liquid pump so that the liquid level inside the liquid cell is changed, Tilting the working electrode of the electrochemical cell so that a first part of the working electrode protrudes from the liquid during operation, a second part of the working electrode is wetted by the liquid, and a third part of the working electrode is located within the liquid. Providing the liquid in the electrochemical cell and pumping the liquid from the liquid pumping area of ​​the liquid pump such that a first part of the working electrode protrudes from the liquid during operation, a second part of the working electrode is wetted by the liquid, and a third part of the working electrode is located within the liquid. Illuminating the working electrode of the electrochemical cell with particles or radiation from the illumination system, so that successively the first part of the working electrode, which protrudes from the liquid during operation, the second part of the working electrode, which is wetted by the liquid, and the third part of the working electrode, which is located within the liquid, are illuminated.

14. Use of the vacuum system (100; 100”) according to claim 10 for: surface analysis, measurement of surface reactions, measurement of liquid-solid reactions, a measurement of liquid-gas reactions, a measurement of liquids, a measurement of thin films, a detection of foreign substances in liquids, a photoemission measurement, a photoelectron spectroscopy measurement near atmospheric pressure, an X-ray photoelectron spectroscopy measurement near atmospheric pressure, an electrochemical measurement, a battery analysis, an oxidation measurement, an electrolyte measurement, an electrode measurement, a sample measurement through a liquid, a quality control, a corrosion measurement, a catalyst measurement, a pressure-dependent measurement, a measurement of a biological sample, a potentiometry measurement, a measurement of a supersaturated liquid.g of the method (500) according to claim 12 or 13 for: a surface analysis, a measurement of a surface reaction, a measurement of liquid-solid reactions, a measurement of liquid-gas reactions, a measurement of liquids, a measurement of thin films, a detection of foreign substances in liquids, a photoemission measurement, a photoelectron spectroscopy measurement near atmospheric pressure, an X-ray photoelectron spectroscopy measurement near atmospheric pressure. atmospheric pressure, an electrochemical measurement, a battery analysis, an oxidation measurement, an electrolyte measurement, an electrode measurement, a sample measurement through a liquid, a quality control, a corrosion measurement, a catalyst measurement, a pressure-dependent measurement, a measurement of a biological sample, a potentiometry measurement, a measurement of a supersaturated liquid.