121 results about "Free-electron laser" patented technology

A free electron laser for generating a Smith-Purcell radiation. In one embodiment, the free electron laser includes a grating having a grating surface, an electron emitter for generating a beam of electrons, and a guiding member positioned therebetween the electron emitter and the grating for directing the beam of electrons along a path extending over the grating surface of the grating with a focal point so that in operation a Smith-Purcell radiation and an evanescent wave are generated by interaction of the beam of electrons with the grating. In operation, the beam current of the beam of electrons is equal to or greater than a threshold current and the group velocity of the evanescent wave is substantially close to zero or negative so that the evanescent wave travels backward to allow electrons in the beam of electrons are bunched by interaction with the evanescent wave to substantially enhance the Smith-Purcell radiation over the range of wavelengths.

A system generates FIR laser radiation. An electron source generates an electron beam. A grating horn interacts with the electron beam to produce the FIR laser radiation. The grating horn may comprise a flat base and a pair of grating elements attached to the base, each of the grating elements being ruled with a grating period, the grating elements oriented in phase and in substantial symmetry about a normal to the flat base.

A free electron laser is disclosed. The free electron laser separates pulse bunching at a first electron energy from light generation stage at a second electron energy. A first wiggler pulse bunches the electrons and a second wiggler generates light. The first wiggler may be an optical buncher with an injected seed wave, and the second wiggler can be a magnetic wiggler, optical wiggler, resonant transition radiator, parametric radiation radiator, Cerenkov radiation radiator or a Smith-Purcell radiation radiator. The disclosed free electron laser is particularly useful for lithography applications at an extreme ultraviolet wavelength range near 13.5 nm.

A method and apparatus for ablating material. The material is preferably a heterogenous or composite material, such as animal tissue. A table top laser system can be employed in the invention. Alternatively, a larger laser, such as a free electron laser can be employed.

The invention discloses a free electron laser based tunable narrow-band compact terahertz radiation source. The free electron laser based tunable narrow-band compact terahertz radiation source comprises a laser source, a pulse accumulation light path, a reflecting mirror, a photocathode multi-cavity microwave electron gun, a solenoid coil and an undulator, wherein laser pulses emitted from the laser source are accumulated by n times through the pulse accumulation light path to generate a laser pulse string composed of 2n laser pulses, the laser pulse string irradiates on the surface of a negative electrode of the photocathode multi-cavity microwave electron gun by the reflecting mirror, and an electron bunch string is emitted from the surface of the negative electrode by a photoelectric effect, is accelerated by a microwave field generated by a microwave power source in a chamber of the photocathode multi-cavity microwave electron gun and enters the undulator after being transversely focused by a magnetic field of the solenoid coil so that electromagnetic radiation associated with THz waveband is stimulated. The technical scheme disclosed by the invention has the characteristics of compact structure, continuous and adjustable frequency and narrow bandwidth, and is easy to implement technically.

A method of avoiding CSR induced beam quality defects in free electron laser operation by a) controlling the rate of compression and b) using a novel means of integrating the compression with the remainder of the transport system: both are accomplished by means of dispersion modulation. A large dispersion is created in the penultimate dipole magnet of the compression region leading to rapid compression; this large dispersion is demagnified and dispersion suppression performed in a final small dipole. As a result, the bunch is short for only a small angular extent of the transport, and the resulting CSR excitation is small.

The invention relates to a double-electron-beam double-grating based terahertz free electron laser source. The laser source comprises two groups of electron guns, metal rectangular gratings and collectors with totally-consistent parameters; the two electron guns are corresponding to the two collectors respectively; one metal rectangular grating is positioned between the corresponding electron gun and the correcting collector on one side while the other metal rectangular grating is positioned between the corresponding electron gun and the correcting collector on the other side; the two metal rectangular gratings are symmetrical; and a variable open resonant cavity is formed by the two metal rectangular gratings. The uniform-velocity band-shaped electron beams generated by the electron guns skim over the surfaces of the metal rectangular gratings and finally enter the collectors; the two electron beams generate two special Smith-Purcell radiating waves along the perpendicular direction on the surfaces of the metal rectangular gratings respectively; the two special Smith-Purcell radiating waves are reflected back and forth between the two metal rectangular gratings to form a resonant mode in the open resonant cavity, and are converted into electromagnetic wave energy; and the electromagnetic wave energy is amplified and finally output through a port.

The invention discloses a full-optically driven full-coherence table type X ray free electron laser which obtains temporal and spatial full-coherence X ray free electron lasers by using a full-optical driving method. For both HH (higher harmonic) injection source and high-energy electron injection source, the same laser system is adopted for driving, thus the output of full-coherence table type Xtype free electron lasers can be produced. The full-coherence 'water window' band (even the keV-magnitude attosecond light source) is very important in the fields of physics, chemistry, life science,material science and the like.

A Free Electron Laser source includes: a fiber-based laser having a plurality of amplifying fibres wherein an initial laser pulse is distributed and amplified, and element for grouping together the elementary pulses amplified in the fibre in order to form an a single amplified global laser pulse; a laser plasma accelerator wherein the global laser pulse generates relativistic electron beams, a beam focusing system transporting electron beams from the laser plasma accelerator, an undulator wherein relativistic electron beams generate an electromagnetic beam, and a beam separator system, wherein the electron beam and the electromagnetic beam are separated.

The invention discloses nitrogen-gas-protection-free electron-beam-cured coating/ink and preparation and curing methods thereof. The coating/ink contains the ingredients in parts by mass: 30-45 parts of unsaturated bond containing resin or rubber, 3-8 parts of sensitizer, 0-15 parts of activated thinner, 15-24 parts of non-activated thinner, 15-25 parts of color paste, 0.15-1 part of auxiliaries and 0.5-2.5 parts of initiator. The preparation method comprises the step of stirring at normal temperature in stages until liquid is uniform. The curing method comprises the steps of firstly carrying out UV (ultraviolet) initial curing on a substrate, and then, carrying out nitrogen-gas-protection-free electron-beam-irradiation-cured shaping. According to the nitrogen-gas-protection-free electron-beam-cured coating/ink and the preparation and curing methods thereof, curing process flows of the electron-beam-cured coating/ink are simplified, the work efficiency is increased, and the production cost of the electron-beam-cured coating/ink is reduced, so that the electron-beam-cured coating/ink is worthy of popularization and application.

The invention provides a device and method for generating an extreme ultraviolet tunable monochromatic coherent light source, the method is characterized by utilizing interacting actions of 800 nm femtosecond laser and gas to generate ultraharmonics, tuning high order harmonic energy from the frequency comb to a specific degree through the macroscopic phase matching and atoms phase matching technology, and enabling the high order harmonic energy to output single high order harmonic (monochrome) in a specific degree. Furthermore, the specific high order harmonic can conduct tuning through the phase-matching technique, that is, the output wave length is adjustable. The extreme ultraviolet tunable monochromatic coherent light source generated by the device can be used in the fields of high precision detection for micro-nano structures, high precision holographic imaging and high precision carving and the like, and can also be used as an injecting source of a free electron laser, and the application range is extremely broad. And the device has the advantages that extreme ultraviolet can be output, monochrome tuning is realized and the coherence is good.

The invention discloses an independent tuning microwave electron gun with external cathode which is composed of an external negative pole, namely, dipolar gun, a microwave cavity, a tuning mechanism, a first cavity input waveguide, a second cavity input waveguide and a cooling water pipe; the external negative pole and the microwave cavity are connected by Kovar flange argon-arc welding, the tuning mechanism and the microwave cavity are connected by braze welding in a hydrogen furnace, the first cavity input waveguide and the second cavity input waveguide are connected with the microwave cavity by braze welding, but the first cavity input waveguide and the second cavity input waveguide are connected at different longitudinal positions of the microwave cavity with the angles being mutually perpendicular, and then connected with a waveguide transmission line fed with microwave power respectively. The invention is designed to solve manufacture technique, so that the electron gun has simple structure and electron beam is excellent in performance, thus providing a novel electron beam source device for compact type free electron laser and electron linear accelerator.

The present invention relates to ellipsometer and polarimeter systems, and more particularly is an ellipsometer or polarimeter or the like system which operates in a frequency range between 300 GHz or lower and extending to higher than at least 1 Tera-hertz (THz), and preferably through the Infra-red (IR) range up to, and higher than 100 THz, including:

• • a source such as a backward wave oscillator; a Smith-Purcell cell; a free electron laser, or an FTIR source and a solid state device; and
  • a detector such as a Golay cell; a bolometer or a solid state detector;

and preferably including at least one odd-bounce polarization state image rotating system, and optionally including a polarizer, at least one compensator and/or modulator, in addition to an analyzer.

The present invention relates to ellipsometer and polarimeter systems, and more particularly is an ellipsometer or polarimeter or the like system which operates in a frequency range between 300 GHz or lower and extending to higher than at least 1 Tera-hertz (THz), and preferably through the Infra-red (IR) range up to, and higher than 100 THz, including:

• • a source such as a backward wave oscillator; a Smith-Purcell cell; a free electron laser, or an FTIR source and a solid state device; and
  • a detector such as a Golay cell; a bolometer or a solid state detector;

and preferably including at least one odd-bounce polarization state image rotating system, and optionally including a polarizer, at least one compensator and/or modulator, in addition to an analyzer.

The present invention relates to ellipsometer and polarimeter systems, and more particularly is an ellipsometer or polarimeter or the like system which operates in a frequency range between 300 GHz or lower and extending to higher than at least 1 Tera-hertz (THz), and preferably through the Infra-red (IR) range up to, and higher than 100 THz, including:

• • a source such as a backward wave oscillator; a Smith-Purcell cell; a free electron laser, or an FTIR source and a solid state device; and
  • a detector such as a Golay cell; a bolometer or a solid state detector;

and preferably including a polarization state generator comprising:

an odd bounce image rotating system and a polarizer, or two polarizers;

and optionally including least one compensator and/or modulator, in addition to an analyzer.

This invention provides a treatment device for lowering electron affinity, said treatment device being capable of performing an EA surface treatment on a photocathode material or an EA surface retreatment on a photocathode, and an electron-beam device provided with said treatment device. An activation chamber (20) used in a treatment device for lowering electron affinity by vaporizing a surface-treatment material (30) and using the vaporized surface-treatment material (30) to perform an electron-affinity lowering treatment on a photocathode material (52) or an electron-affinity lowering retreatment on a photocathode (52), said activation chamber (20) being characterized by containing holes through which electrons can pass.

A high power extreme ultraviolet (EUV) beam is produced. An electron beam is injected in a compact electron storage ring configured for emission of free-electron laser (FEL) radiation. The electron beam is passed through a magnetic undulator on each of a plurality of successive revolutions of the electron beam around the compact electron storage ring. The electron beam is induced to microbunch and radiate coherently while passing through the magnetic undulator. A portion of the free-electron laser radiation at an extreme ultraviolet wavelength produced by an interaction of the electron beam through the magnetic undulator is outputted.

The invention provides a preparation method of micro-and nanoscale protein crystals capable of stably existing in air. Protein mini-crystals grow through the simple and feasible method, chemical cross-linking is conducted on the mini-crystals through a cross-linking agent, and the protein mini-crystals capable of stably existing in air are obtained. The method is convenient to operate, economical and practical; the prepared protein mini-crystals do not need crystal rings or capillary tubes when used for free electron laser diffraction, and background scattering can be eliminated; when the crystals are used as a catalyst, a sample can not be dissolved and can be repeatedly used.

An improved method for the production of single walled carbon nanotubes that utilizes an RF-induction heated side-pumped synthesis chamber for the production of such. Such a method, while capable of producing large volumes of carbon nanotubes, concurrently permits the use of a simplified apparatus that allows for greatly reduced heat up and cool down times and flexible flowpaths that can be readily modified for production efficiency optimization. The method of the present invention utilizes a free electron laser operating at high average and peak fluence to illuminate a rotating and translating graphite/catalyst target to obtain high yields of SWNTs without the use of a vacuum chamber.

Various embodiments of undulators, methods of fabricating undulators, and systems incorporating undulators are described. Certain embodiments provide a compact, electromagnetic undulator. The undulator may comprise a substrate and one or more electromagnets, which may be formed on the substrate. Certain embodiments have a period not greater than about 5 mm. The undulator may be operatively coupled with a particle accelerator to provide a free electron laser system.

The invention provides a 1210 nm optical parameter oscillator, relating to the photoelectron technical field. The oscillator consists of an input mirror, a small aperture, two nonlinear optical crystals and an output mirror set. The oscillator generates the laser with the length of 1210 nanometers which can be up to the laser power necessary to burning fat after amplified. The optical parameter oscillator is an all solid state laser with high efficiency. Compared with a free electron laser, the optical parameter oscillator can greatly lower the medical cost and has the advantages of low cost, compact system, etc. Therefore, the optical parameter oscillator has good market propect.

Limiter optics for an ignition feedback regenerative free electron laser amplifier have a pickoff mirror direct a portion of the output from the free electron laser through a focusing assembler. After expanding this pickoff beam spatially and temporally, the focusing assembler first focuses the expanded pickoff beam to a focal point, the expanded focused pickoff beam is then passed through a movable limiter plate which serves as an off switch if the pickoff beam is above a predetermined intensity and then refocuses the expanded pickoff beam back into the free electron laser to enhance the emission intensity of the output beam. The expanded mirror may be a half silvered mirror or a phased mirror with a plurality of mesas. The pickoff mirror may be convex. The half silvered mirror produces two segments in the pickoff beam with a time lag dependent on the thickness of the mirror. The phased mirror creates a plurality of parallel beams for the expander beam with a predetermined time lag for each of said paralleled beams created. Orientation of a phased mirror may be rotated to control spatial separation of parallel beams.

Passage through LINACs of electron bunches in their acceleration phase is co-ordinated with passage through the LINACs of electron bunches in their deceleration phase. Each successive pair of electron bunches are spaced in time by a respective bunch spacing, in accordance with a repeating electron bunch sequence. The electron source provides clearing gaps in the electron bunch sequence to allow clearing of ions at the undulator. The electron source provides the clearing gaps in accordance with a clearing gap sequence such that, for each of the plurality of energy recovery LINACS, and for substantially all of the clearing gaps:- for each passage of the clearing gap through the LINAC in an acceleration phase or deceleration phase the clearing gap is co-ordinated with a further one of the clearing gaps passing through the LINAC in a deceleration phase or acceleration phase thereby to maintain energy recovery operation of the LINAC.

The invention discloses a free electron laser terahertz radiation source based on a higher harmonic wave generation method. The radiation source comprises an electron gun, a radiator and a solenoid magnet. The electron gun is connected with a vacuum pipeline. The radiator is arranged in the interior of the vacuum pipeline. The solenoid magnet wraps the exterior of the vacuum pipeline. There are different modes from a base mode to a higher mode in the radiator and the different modes correspond to different radiation frequencies. By selecting parameters and electron energy of the radiator, the frequency of the higher mode of the radiator is allowed to be integral multiple of that of the base mode, i.e., the harmonic wave of the base mode frequency. By use of a harmonic wave increasing method in which the frequency of the higher mode of the radiator is integral multiple of that of the base mode, a high-power and high-frequency THz radiation source can be generated by use of an electron beam which less requires parameters and by use of a large-size waveguide.