Method and device for controlling Geiger-Muller tube

Abstract

The radiation detection device (210) comprises: a Geiger-Muller tube (220) comprising a chamber (222) containing an anode (230) and a cathode (240); a first connection configured to connect the anode (230) to an anode activation potential; and a second connection configured to connect the cathode (240) to a cathode activation potential, where the first connection comprises a permanent connection with a voltage source (270), or the first connection consists of a permanent connection with a voltage source (270). The device includes a transistor (281) configured to temporarily connect the cathode to its activation potential.

Description

Technical Field

[0001] The present invention relates to a method and apparatus for controlling a Geiger-Muller tube. In particular, but not exclusively, the present invention relates to a method and apparatus for controlling and / or measuring the output from a Geiger-Muller tube. Background Art

[0002] A radiation detection device (e.g. a radiation dosimeter) is an electronic device that measures the exposure level (dose) from an external source of ionizing radiation. Radiation dosimeters are therefore often used to monitor and / or record radiation doses and / or dose rates in a specific environment. This can be used for continuous monitoring at a specific location. Alternatively, this can also be used to monitor ionizing radiation to which an individual may be exposed, in which case the dosimeter is often worn by the person being monitored. Such devices are often referred to as electronic personal dosimeters. Electronic personal dosimeters typically provide continuous readings of the cumulative dose and / or instantaneous dose rate, and are often equipped with a warning element that provides a signal to the user (e.g., an audible sound or visual display) when a preset cumulative dose or dose rate is exceeded.

[0003] Electronic personal dosimeters are battery powered and typically use a small Geiger-Müller (GM) tube or semiconductor (Si chip) inside which the ionizing radiation releases an electrical charge that generates a measurable current. Examples of such devices include the Tracerco TM Personal electronic dosimeter.

[0004] The Geiger-Muller tube consists of a chamber filled with an inert gas or halogen and a quenching gas or vapor such as a hydrocarbon. Two electrodes are mounted in the chamber, which apply a potential difference of several hundred volts across the chamber. When ionizing radiation strikes the tube, the gas in the chamber is ionized by the incident radiation, thereby generating charged particles within the chamber. The electric field generated by the voltage between the electrodes causes the generated charges to move within the chamber, and the resulting electrical pulses are measured by the electronics within the instrument.

[0005] The problem with radiation detectors using GM tubes is that with a continuous voltage applied, after each ionization event, the tube requires a certain amount of time to charge between pulses in order to be ready to count subsequent events (since it is essentially a capacitor being charged through a large value resistor). This is commonly referred to as "dead time". The actual dead time depends on several factors (including the active volume and shape of the detector), so it is difficult to correct for. This dead time can cause the GM tube to saturate, which can lead to an underestimation of event rates, especially in high radiation environments.

[0006] Some studies (see TJ Lewis, GEIGER-COUNTER OPERATION WITHOUT DEAD-TIME, Appl. sci. Res., 1955, Part B, Vol. 5, Queen Mary College, London) have proposed that it is theoretically possible to switch Geiger-Muller (GM) tubes to eliminate the effects of dead time and improve count rate measurements. This "time-to-count" method is independent of dead time and limits the number of discharges in high radiation fields by introducing a fixed waiting time between discharges (i.e., operating the counter by a pulse voltage). The waiting time is selected to be longer than the recovery time of the tube. However, to date, no practical technical means have been disclosed to implement this theoretical principle in an effective and reliable manner.

[0007] As mentioned above, in a Geiger-Muller tube, the GM tube comprises a chamber filled with halogen gas and a quenching medium, in which two electrodes (anode and cathode) are mounted, which apply a potential difference of several hundred volts in the chamber. Typically, in order to "charge" the tube, the voltage at the anode is increased to its target value (e.g., 550-600V). The voltage at the cathode is usually at a potential of 0V. The anode voltage is usually generated by a current passing through a high-resistance resistor on the anode to prevent or limit the risk of arcing between the electrodes during ionization. However, this traditional arrangement has some disadvantages. First, there is a "dead time" after the ionization event (discharge caused by incident radiation) occurs, which is caused by two effects: (i) the time required for multiple electron avalanches to terminate; and (ii) due to the large current limiting resistor on the anode, the tube takes a certain amount of time to charge back to full voltage, during which time the probability of the GM tube detecting radiation is reduced. In addition, before the ionization event is detected, the voltage is usually continuously applied while the tube is charging, which is very power-consuming at high count rates.

[0008] It is an object of the present invention to solve or alleviate one or more problems associated with the prior art. Summary of the invention

[0009] The inventors have developed systems and methods configured to control Geiger-Mueller tubes that can extend the detection range of radiation detection equipment, i.e., be able to operate at very high radiation fields while maintaining sensitivity to low count rates. The systems of the invention may have one or more of the following advantages:

[0010] - Faster activation of GM tubes

[0011] - Lower risk of arcing

[0012] - Reduce dead time

[0013] - Capability to detect higher count rates

[0014] - Expand the scope of detection

[0015] - Lower power consumption

[0016] - Reduced operating costs

[0017] - Smaller size.

[0018] According to a first aspect of the present specification, there is provided a radiation detection device, the radiation detection device comprising:

[0019] A Geiger-Muller tube comprises a chamber containing two or more electrodes, wherein the chamber is configured to be charged by temporarily connecting the two or more electrodes to their respective activation potentials.

[0020] The chamber may provide or include a pair of electrodes, typically an anode and a cathode. The chamber may be configured to charge the chamber by temporarily connecting the anode and the cathode to their respective activation potentials. The activation potential of the anode may be in the range of about 300V-700V, such as about 440V-600V, typically about 550V. The activation potential of the cathode may be in the range of about 0V-50V, typically about 0V. The anode may be maintained at a constant potential, such as the anode activation potential. The device may also include a voltage source unit configured to provide the anode activation potential.

[0021] Advantageously, the anode may not include or may not be coupled to a resistor. The anode activation potential may not be determined or defined by a resistor. It is understood that when the voltage source unit providing the activation potential to the anode includes a resistor, the resistor may have a sufficiently low ohmic value so that when the current load changes, the activation potential provided by the voltage source unit is not determined or defined by the resistor.

[0022] In a conventional Geiger-Muller tube, the anode voltage is usually generated by passing a current through a high-value resistor on the anode. This is usually done to minimize the risk of arcing between the electrodes during ionization. However, this setup usually requires that the voltage be continuously applied when activating the GM tube until an ionization event is detected, which is not only power-consuming but also still carries a certain risk of arcing. In addition, due to the large current-limiting resistor on the anode, the tube requires a non-negligible time to charge back to full voltage, thereby reducing the maximum count rate that the system can detect.

[0023] In this arrangement, the chamber is configured to charge the chamber by temporarily connecting two or more electrodes of the chamber (e.g., an anode and a cathode) to their respective activation potentials, and then disconnecting at least one electrode (usually the cathode) from its activation potential until an ionization event occurs. The inventors have discovered that by utilizing the inherent capacitive properties of the GM tube, temporary activation of the tube is sufficient to charge the tube and maintain the charge or activation state long enough until an ionization event occurs. This has a number of benefits:

[0024] - First, when the gas in the GM tube is ionized, the tube is discharged instantly because there is no potential difference actively applied at the instant of ionization. Therefore, the risk of arcing can be eliminated or at least greatly reduced. This may also result in a faster system capable of detecting higher count rates.

[0025] - Secondly, the power required to keep the tube in a charged state can be reduced, especially at high count rates. This is because, in this system, the tube is charged at a preset time interval (usually 1ms) after the ionization event. Therefore, at very high count rates, the number of times the tube is charged will tend to 1000 times per second. In contrast, if the tube is continuously powered, the maximum theoretical count rate will tend to 10 per second. 6 times. Therefore, the current required to keep the tube charged can be reduced by up to 1000 times in this system.

[0026] Activation of the GM tube (e.g., connection of the cathode to its activation potential) can be performed in less than 1 ms, such as less than 100 μs, such as less than 10 μs, and typically less than 5 μs. Activation of the GM tube can be performed between about 10 ns-100 μs, such as about 100 ns-10 μs, typically about 500 ns-5 μs, such as between 500 ns-2 μs. In one or more embodiments, the activation time can be about 1.2 μs. Therefore, the activation time can be shorter than a typical or expected time-count value, and / or, can be shorter than the current pulse generated by the discharge of the tube.

[0027] The anode may be kept at a constant potential, eg its activation potential.The anode may be connected (eg permanently connected) to a voltage source (eg via a voltage supply unit).

[0028] Advantageously, the cathode may be associated with a switch. The switch may be capable of connecting or disconnecting the cathode to its activation potential (e.g., approximately 0V). The switch may be disposed within a cathode interface unit configured to activate and / or deactivate the cathode, for example, configured to drive the connection and disconnection of the cathode from its activation potential. The cathode switch may include or may be a transistor, preferably an N-type MOSFET ("nFET"). Advantageously, such a switch may provide a very fast way to activate the cathode, thereby providing a very fast way to charge the GM tube. The device may further include a controller, such as a microcontroller unit (MCU), configured to control an anode voltage source and / or a cathode interface unit, such as a switch. Preferably, the controller may be configured to control the anode voltage source and the cathode interface unit.

[0029] According to a second aspect of the present specification, there is provided a radiation detection device, the radiation detection device comprising:

[0030] a Geiger-Muller tube, which includes a chamber containing an anode and a cathode;

[0031] a first connection configured to connect the anode to an anode activation potential; and

[0032] a second connection configured to connect the cathode to a cathode activation potential,

[0033] The first connection comprises a permanent connection to a voltage source, or the first connection consists of a permanent connection to a voltage source.

[0034] The first connection may be provided within a voltage source unit configured to provide an anode activation potential. Advantageously, the first connection may not include a resistor. The anode activation potential may not be determined by a resistor, or may not be defined by a resistor. It will be appreciated that when the voltage source unit providing the activation potential to the anode includes a resistor, such a resistor may have a sufficiently low ohmic value so that the activation potential provided by the voltage source unit is not determined or defined by the resistor. This arrangement may achieve faster activation of the GM tube, lower arc risk and / or shorter dead time.

[0035] The first connection may include a permanent connection to a voltage source, or the first connection may consist of a permanent connection to a voltage source. During operation of the GM tube, the voltage source may be maintained (e.g., continuously maintained) at an anode activation potential. The activation potential of the anode may be in the range of about 300V-700V, such as in the range of about 440V-600V, typically about 550V. The activation potential of the cathode may be in the range of about 0V-50V, typically about 0V.

[0036] The second connection may include a switch. The switch may be capable of connecting or disconnecting the cathode to a cathode activation potential. The cathode activation potential may be about 0V-50V, typically about 0V. The switch may be disposed within a cathode interface unit configured to activate and / or deactivate the cathode, for example, configured to drive the connection and disconnection of the cathode from its activation potential. The switch may include or may be a transistor, preferably an N-type MOSFET ("nFET"). Advantageously, such a switch may provide a very fast way to activate the cathode, thereby providing a very fast way to charge the GM tube.

[0037] Providing a switch in the second connection allows the chamber to be charged by temporarily connecting the cathode of the chamber to its activation potential (e.g., by temporarily closing the switch). In order to activate or charge the GM tube, the switch can be closed for less than 1ms, such as less than 100μs, such as less than 10μs, typically less than 5μs. Activation of the GM tube can be accomplished by closing the switch for a period of about 10ns-100μs, such as about 100ns-10μs, typically about 500ns-5μs, such as 500ns-2μs. Therefore, the activation time can be shorter than the typical or expected time-count value. In addition, the power required to maintain the potential difference between the electrodes is reduced even at high count rates.

[0038] The features related to the device of the first aspect described above are also applicable to the system of the second aspect. For the sake of brevity, they are not repeated here.

[0039] According to a third aspect of the present specification, there is provided a radiation detection device, the radiation detection device comprising:

[0040] a Geiger-Muller tube, which includes a chamber containing an anode and a cathode;

[0041] a first connection configured to connect the anode to an anode activation potential; and

[0042] a second connection configured to connect the cathode to a cathode activation potential,

[0043] Wherein, the second connection includes a switch.

[0044] The switch may be capable of connecting or disconnecting the cathode from its activation potential. The activation potential of the cathode may be in the range of about 0V-50V, typically about 0V. The switch may include or may be a transistor, preferably an N-type MOSFET ("nFET"). Advantageously, such a switch may provide a very fast way to activate the cathode, thereby providing a very fast way to charge the GM tube.

[0045] Providing a switch in the second connection allows the chamber to be charged by temporarily connecting the cathode to its activation potential (e.g., by temporarily closing the switch). To activate or charge the GM tube, the switch can be closed for less than 1ms, such as less than 100μs, such as less than 10μs, typically less than 5μs. Activation of the GM tube can be accomplished by closing the switch for a period of about 10ns-100μs, such as about 100ns-10μs, typically about 500ns-5μs, such as 500ns-2μs. Therefore, the activation time can be shorter than the typical or expected time-count value. In addition, the power required to maintain the potential difference between the electrodes is reduced even at high count rates.

[0046] The first connection can include a permanent connection with a voltage source, or the first connection can be composed of a permanent connection with a voltage source. The voltage source can remain on the anode activation potential. The activation potential of the anode can be in the scope of about 300V-700V, for example, in the scope of about 440V-600V, usually about 550V. The activation potential of the anode can be in the scope of about 0V-50V, usually about 0V.

[0047] Advantageously, the first connection may not include a resistor. The anode activation potential may not be determined by the resistor, or may not be defined by the resistor. It is understood that when the voltage source unit providing the activation potential to the anode includes a resistor, such a resistor may have a sufficiently low ohmic value so that the activation potential provided by the voltage source unit is not determined or defined by the resistor. This arrangement may achieve faster activation of the GM tube, faster discharge under ionization, lower arc risk and / or shorter dead time.

[0048] The features described above in relation to the apparatus of the first or second aspect are also applicable to the system of the third aspect, but are not described in detail here for the sake of brevity.

[0049] According to a fourth aspect, there is provided a method of activating a Geiger-Muller tube, wherein the Geiger-Muller tube comprises a chamber containing two or more electrodes,

[0050] The method includes temporarily connecting two or more electrodes to their respective activation potentials to charge the chamber.

[0051] The chamber may be provided with a pair of electrodes, typically an anode and a cathode. The method may include temporarily connecting the anode and cathode to their respective activation potentials to charge the chamber.

[0052] The method may include providing a first connection configured to connect the anode to its activation potential. The first connection may include a permanent connection to a voltage source, or the first connection may consist of a permanent connection to a voltage source. Advantageously, the first connection may not include a resistor. The anode activation potential may not be determined by a resistor, or may not be defined by a resistor. It will be appreciated that when a voltage source unit providing the activation potential to the anode includes a resistor, such a resistor may have a sufficiently low ohmic value so that the activation potential provided by the voltage source unit is not determined or defined by the resistor. This arrangement may achieve faster activation of the GM tube, faster discharge under ionization, lower arc risk and / or shorter dead time.

[0053] The method may include maintaining a voltage source at the anode at an anode activation potential. The activation potential of the anode may be in the range of about 300V-700V, such as about 440V-600V, typically about 550V.

[0054] The method may include providing a second connection configured to connect the cathode to its activation potential. The activation potential of the cathode may be in the range of about 0V-50V, typically about 0V. The second connection may include a switch. The method may include charging the chamber by temporarily connecting the cathode to the chamber (e.g., by temporarily closing a switch). The switch may include or may be a transistor, preferably an N-type MOSFET ("nFET"). Advantageously, such a switch may provide a very fast way to activate the cathode, thereby providing a very fast way to charge the GM tube.

[0055] According to a fifth aspect of the present specification, there is provided a method of activating a Geiger-Mueller tube, wherein the Geiger-Mueller tube comprises a chamber containing an anode and a cathode; a first connection configured to connect the anode to an anode activation potential; and a second connection configured to connect the cathode to a cathode activation potential,

[0056] The method includes charging the chamber by temporarily connecting the cathode to its activation potential.

[0057] Advantageously, the second connection may comprise a switch. The method may comprise temporarily connecting the cathode to its activation potential by temporarily closing the switch to charge the chamber. The activation potential of the cathode may be in the range of about 0V-50V, typically about 0V. The switch may comprise or may be a transistor, preferably an N-type MOSFET ("nFET"). Advantageously, such a switch may provide a very fast way to activate the cathode, thereby providing a very fast way to charge the GM tube.

[0058] According to a sixth aspect of the present specification, there is provided a controller for a radiation detection device, the radiation detection device comprising:

[0059] a Geiger-Muller tube comprising a chamber containing an anode and a cathode, wherein the chamber is configured to charge the chamber by temporarily connecting the anode and cathode to their respective activation potentials;

[0060] a voltage source unit configured to provide (eg, continuously and / or permanently provide) an anode activation potential; and

[0061] The cathode interface unit is configured to drive the cathode to be connected to and / or disconnected from its activation potential, wherein the controller is configured to control the driving of the anode voltage source unit and the driving of the cathode interface unit.

[0062] The features described above in relation to the apparatus of the first to third or sixth aspects are also applicable to the method of the fourth or fifth aspect, and vice versa, but for the sake of brevity they are not described in detail here. BRIEF DESCRIPTION OF THE DRAWINGS

[0063] In order to better understand the invention and to show how it may be implemented, some embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

[0064] Figure 1 is a schematic diagram of a radiation detection device in the prior art;

[0065] Figure 2 The general principle of the "time-to-first-count" method is explained;

[0066] Figures 3 to 5 A schematic diagram showing a radiation detection device according to an embodiment; and

[0067] Figure 6 Instructions for use Figures 3 to 5 The device implements the principle of the "time-to-first count" method. DETAILED DESCRIPTION

[0068] As described in the Summary of the Invention, the present specification provides a system and method for controlling a Geiger-Mueller tube, which achieves an expansion of the detection range of a radiation detection device, that is, the ability to operate under very high radiation fields while maintaining sensitivity to low count rates. Some more detailed examples are listed below to illustrate different embodiments of the present invention.

[0069] Figure 1 1 is a schematic diagram illustrating a radiation detection device in the prior art, generally designated 10. The device includes a GM tube 20, which includes a chamber filled with an inert gas and a quenching gas or vapor. Two electrodes (anode 30 and cathode 40) are installed in the chamber, and the two electrodes apply a potential difference of hundreds of volts in the chamber.

[0070] In this arrangement, the high voltage 34 on the anode is usually generated by the passage of current through a high-resistance resistor 32 on the anode 30. This is to minimize the risk of arcing between the electrodes during ionization in the GM tube 20. However, this arrangement usually requires that the voltage be continuously applied when activating the GM tube 20 until an ionization event is detected, which is not only power-consuming but also still has a certain arc risk. In addition, due to the large current-limiting resistor 32 on the anode, the tube requires a non-negligible time to charge back to full voltage, which results in a "dead time" during which the GM tube cannot detect radiation. Resistor 32 is usually of a large value to provide the above characteristics, in this case 2MΩ.

[0071] At cathode 40, when a current pulse passes through the GM tube, a voltage is generated across resistor 42 due to the radiation, because voltage = current x resistance. A short voltage pulse across resistor 42 switches transistor 51 (or another amplifier element). This signal can then be connected to a counting device 60, such as a microcontroller. By detecting the number of counts per second, the radiation "dose rate" (Sieverts / hour) can be calculated. The relationship between count rate and dose rate is approximately proportional.

[0072] As previously mentioned, a disadvantage of this method of operating the GM tube 20 is that it takes a certain amount of time for the GM tube 20 to charge back to 550V due to the large current limiting resistor 32. In addition, the gas in the GM tube 20 must have time to "quench" any free electrons before the next radiation event is detected. This charging and quenching typically creates a "dead time" during which the GM tube 20 cannot detect radiation. This limits the maximum count rate that the detector can measure.

[0073] Figure 2 The general principle of the "time-first count" method is described. Under this method, such as that proposed by TJ Lewis (1955) discussed in the background section, the sequence 110 is initiated by simultaneously opening the GM tube 120a and starting the timer 120b. Figure 2 In the instructions, hardware-related steps are suffixed with "a" and firmware-related steps are suffixed with "b".

[0074] When ionizing radiation hits the GM tube 130a, an ionization event occurs. This will generate a pulse signal 135a in the circuit. This simultaneously causes the tube to shut down 140a and the timer to stop 140b.

[0075] The time required for the system buffering is then recorded 150b, and a period of time longer than the dead time associated with the tube (e.g., 1 ms) must pass 160b before the next sequence 110 can be started again. In this example, the waiting time 160b is selected to be 1 ms, but it will be appreciated that the waiting time selected may be such that the tube returns to ground, for example, between about 50 μs and about 700 μs.

[0076] However, as mentioned above, a difficulty with the method described by TJ Lewis (1955) is that at the beginning of each cycle, when the tube is turned on, it takes a non-negligible amount of time for the tube to reach its target full potential, which may introduce timing errors. This makes the implementation of the technique difficult or impractical.

[0077] Figures 3 to 5 Schematic diagram of a radiation detection device 210 according to an embodiment is shown. Although obviously different, for ease of reference, Figure 3 The radiation detection device 210 and Figure 1 The radiation detection device 10 in FIG. 1 is substantially similar, and like parts are represented by like numbers but incremented from "200".

[0078] The radiation detection device 210 includes a Geiger-Mueller tube 220, which includes a chamber 222 containing an anode 230 and a cathode 240. In this embodiment, the Geiger-Mueller tube circuit is designed for explosion-proof scenarios (intrinsically safe, referred to as "IS") and non-IS applications.

[0079] Anode 230 is powered by a 550V power supply unit 270 (see Figure 4 ) and is directly connected to the 550V power supply unit 270 to place and / or maintain the anode at its activation potential. Figure 1 Unlike the configuration of FIG. 1 , in this configuration, the anode 230 is not connected to a resistor to provide the target activation potential, which can help reduce the dead time. The cathode 240 is connected to the interface circuit 280 (see Figure 5 ). Both the power supply unit 270 and the interface circuit 280 are connected to a microcontroller unit (MCU) 290, using a through current limiting connection to meet IS requirements.

[0080] In IS applications, the entire module device 210 may be potted (encapsulated) for IS applications, including the GM tube 220. For convenience, in the event of a GM tube failure, a portion of the device 210 (e.g., housing portion or sleeve) may be discarded and replaced with a replacement GM tube potting module as a whole.

[0081] Reference Figure 4 , the power supply unit 270 has a small resistor 271, which is used only to limit the ignition current when the diodes 272, 273 limit the voltage that can be fed back from the high voltage (HV) power supply. This is done for IS protection. Although the power supply unit 270 includes the resistor 271, it is understood that the ohmic value of the resistor 271 is very small (3.9Ω in this example) so that the voltage provided by the unit 270 is not determined or defined by the resistor 271 (unlike conventional systems).

[0082] A switched inductor 274 is provided which is the basis of the boost regulator. The switched inductor 274 generates a transient voltage of approximately 80V. The switching operation is controlled by a controller 275 which drives a transistor 276. The controller 275 operates at a set frequency determined by a set resistor.

[0083] When the first stage charge pump reaches V>71V, comparator 277 shuts down the supply at the MOD pin of controller 275 to prevent further switching. The effect of this is that controller 275 operates only to "top up" the HV supply.

[0084] In this example, a seven-stage charge pump is used to obtain 550 V. Capacitor 278 maintains the voltage of the GM tube and quickly charges the tube after an ionization event.

[0085] Reference Figure 5 , the interface circuit 280 has a transistor 281 (Q4) which connects the GM tube cathode 240V to 0V. In this embodiment, the transistor 281 is an N-type MOSFET ("nFET"). Advantageously, such a transistor can provide a very fast way to activate the cathode 240, thereby providing a very fast way to charge the GM tube 220.

[0086] Transistor 281 is normally in the off state. Transistor 281 is turned on for 1.2us, but in reality it is fully turned on for only about 700ns. This period of time is sufficient to charge GM tube 220 to 550V. The GM220 tube can be modeled as a 1.8pF capacitor. Experiments have shown that once charged, the tube 220 will maintain its charge indefinitely due to the low leakage current through transistor 281, but the circuit is configured to charge the tube 220 once every 100ms to ensure that the GM tube 220 remains "primed".

[0087] When an ionization event occurs in the tube 220, the tube 220 discharges through the capacitor 282 and turns on the transistor 283 (Q3). This will produce a short (less than 100 μs) active low pulse at the output of the circuit. When the pulse is detected, the MCU 290 waits for a preset time (1 ms in this embodiment) to allow the tube 220 to quench. Then, the MCU 290 outputs a 1.2 us signal to the transistor 281 to restart the working cycle.

[0088] Figure 6 Instructions for use Figures 3 to 5 The device implements the principle of the "time-first count" method. Figure 2 As shown, hardware-related steps are suffixed with an "a", and firmware-related steps are suffixed with a "b".

[0089] In this method, as detailed above, the cathode is connected to 0V for approximately 1.2 μs via the nFET to pre-charge the GM tube—charged to 550 V. Although the "connection time" in this example is 1.2 μs, it can be understood that the specific amount of time can be selected within a very short time range, that is, less than the pulse width 360b.

[0090] In this embodiment, sequence 310 is initiated by simultaneously precharging the GM tube 320a and starting the timer 320b of the MCU 290. In other words, in this embodiment, the timer is started at the beginning of the charging pulse. However, it is understood that in other embodiments, the counter can be started at the end of the charging pulse. In other words, the timer start 320b can occur immediately at the end of the GM tube precharging 320a.

[0091] When ionizing radiation hits the GM tube 330, an ionization event occurs. This will generate a pulse signal 335a in the circuit. This simultaneously causes the tube to discharge momentarily 340a and the timer to stop 340b. The time required for the system buffer is then recorded 350b, and the next sequence 310 is started again after a preset time period (e.g., 1 ms) (160b) selected for the device 210.

[0092] The present method and apparatus are capable of implementing a "time-to-first count" approach while overcoming many of the associated disadvantages or limitations of the prior art.

Claims

1. A radiation detection device, characterized in that: include: A Geiger-Müller tube, which includes a chamber containing two or more electrodes, The chamber is configured to be charged by temporarily connecting the two or more electrodes to their respective activation potentials. 2 . The radiation detection device according to claim 1 , wherein the chamber comprises an anode and a cathode, wherein the chamber is configured to charge the chamber by temporarily connecting the anode and the cathode to their respective activation potentials. 3 . The radiation detection device according to claim 2 , wherein the activation potential of the anode is approximately 550 V, and wherein the activation potential of the cathode is approximately 0 V. 4 . The radiation detection device according to claim 2 , wherein the anode is maintained at a constant potential.

5. The radiation detection device according to any one of claims 2 to 4, wherein the device comprises a voltage source unit configured to provide the anode activation potential. 6 . The radiation detection device according to claim 5 , wherein the anode activation potential is not determined or defined by a resistor.

7. The radiation detection device according to any one of claims 2 to 6, wherein the chamber is configured to charge the chamber by temporarily connecting the cathode of the chamber to its activation potential and then disconnecting the cathode from its activation potential until an ionization event occurs.

8. The radiation detection device according to any one of claims 2 to 7, wherein the cathode is associated with a switch capable of connecting or disconnecting the cathode from its activation potential.

9. The radiation detection device of claim 8, wherein the cathode switch comprises a transistor, optionally an N-type MOSFET ("nFET").

10. The radiation detection device according to any of the preceding claims, wherein the device comprises a microcontroller unit (MCU) configured to control a voltage source of the anode and / or a switch of the cathode.

11. A radiation detection device, characterized in that: include: a Geiger-Muller tube, which includes a chamber containing an anode and a cathode; a first connection configured to connect the anode to an anode activation potential; as well as a second connection configured to connect the cathode to a cathode activation potential, The first connection comprises a permanent connection to a voltage source, or the first connection consists of a permanent connection to a voltage source.

12. A radiation detection device, characterized in that: include: a Geiger-Muller tube, which includes a chamber containing an anode and a cathode; a first connection configured to connect the anode to an anode activation potential; as well as a second connection configured to connect the cathode to a cathode activation potential, Wherein the second connection comprises a switch.

13. A method of activating a Geiger-Muller tube, wherein the Geiger-Muller tube comprises a chamber containing two or more electrodes, It is characterized in that The method includes temporarily connecting the two or more electrodes (optionally, an anode and a cathode) to their respective activation potentials to charge the chamber.

14. The method according to claim 13, comprising: A first connection is provided that is configured to permanently connect the anode to its activation potential.

15. The method according to claim 13 or 14, comprising: The voltage source to the anode is maintained at the anode activation potential.

16. The method according to claim 13 or 14, comprising: A second connection is provided that is configured to connect the cathode to its activation potential. The method of claim 16 , wherein the second connection comprises a switch.

18. The method according to claim 17, wherein the method comprises: By momentarily closing the switch, the cathode is temporarily connected to its activation potential to charge the chamber.

19. A method according to claim 17 or 18, wherein the switch comprises a transistor, optionally an N-type MOSFET ("nFET").

20. A method of activating a Geiger-Muller tube, wherein the Geiger-Muller tube comprises a chamber containing an anode and a cathode; a first connection configured to connect the anode to an anode activation potential; and a second connection configured to connect the cathode to a cathode activation potential, Characterized in that the method includes: charging the chamber by temporarily connecting the cathode to its activation potential.

21. A controller for a radiation detection device, wherein the radiation detection device comprises: a Geiger-Muller tube comprising a chamber containing an anode and a cathode, wherein the chamber is configured to charge the chamber by temporarily connecting the anode and the cathode to their respective activation potentials; a voltage source unit configured to continuously and / or permanently provide the anode activation potential; as well as a cathode interface unit configured to drive the connection and / or disconnection of the cathode from its activation potential, It is characterized in that the controller is configured to control the driving of the anode voltage source unit and the driving of the cathode interface unit.

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