Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
  • H01J63/00—Cathode-ray or electron-stream lamps

Definitions

• the present invention relates to a process for the production of photons, in the range of ultraviolet wavelengths, comprising the implantation in a solid matrix of ions of inert gas or respectively insoluble with respect to the matrix, l excitation of the gas em trapped in the form of extended defects of the solid matrix, and the emission of said photons by the excited gas, as well as to a device for the implementation of this process.
• Common light sources for the near, far, and extreme ultraviolet wavelength ranges are generally discharge sources where light is produced by passing an electrical discharge through a capillary containing noble or other gases at pressures between 10 and a few tens of thousands of Pa.
• a commonly used gas a continuous emission spectrum results from the formation in the discharge and the subsequent radiative decay, of excited helium molecules He 2.
• synchro. ton Another important source of radiation in this spectrum range is the synchro. ton, which is a complicated and expensive installation, accessible only in a few places in the world.
• the object of the present invention is the development of a process and a device for producing photons in the range of ultraviolet wavelengths which sawing simple and inexpensive while giving results comparable to discharge sources.
• ion bombardment of a surface of the solid matrix is carried out with low-energy ions of at least one gas as mentioned above, so as to obtain an implantation at a shallow depth of gas in the solid matrix, and then an electron bombardment, at low energy, of the solid matrix, with excitation of the trapped gas and emission of the abovementioned photons.
• the method comprises the implantation at low depth of gas ions by one face of a solid matrix in mass and the electron bombardment of this same face with emission of the aforementioned photons induced from of this face.
• the method comprises the implantation at low depth of gas ions in a solid lamellar matrix with a thickness of less than 1 ⁇ m, and the above-mentioned electronic bombardment of one of the faces of this matrix with emission of the aforementioned photons induced from the other face of the matrix.
• I1 is also provided, according to the invention, a device for implementing the method according to the invention, this device comprising a vacuum envelope, a solid matrix, in which are implanted shallow ions of at least one inert gas or insoluble gas respectively vis-à-vis the matrix, this matrix being mounted on a support inside the vacuum envelope, an electron production apparatus capable of subjecting the matrix to low electron bombardment energy and an electrical connection connecting the matrix to the outside, as well as an output for the photons produced, provided in the envelope.
• FIG. 1 illustrates, diagrammatically, a device implementing a method for producing photons according to the invention
• FIG. 2 illustrates, diagrammatically, a device implementing an alternative embodiment according to the invention
• FIG. 3 shows, in more detail, a view partially in axial section through a device according to the invention.
• FIG. 4 represents the fluorescence spectrum obtained by the use of a device according to the invention.
• the units plotted on the abscissa represent the wavelengths of the fluorescence spectrum and on the ordinate plots are arbitrary emission intensity units.
• identical or analogous elements are designated by the same references.
• the device illustrated in FIG. 1 comprises a solid matrix 1 which is prepared by implantation of low energy He ions in an Al sheet with a thickness of less than ⁇ m.
• a bombardment of low energy He ions of the order of 5 keV, allows the implantation of a high concentration (locally greater than 10 atom%) of He over a depth of a few tens to a few thousand ⁇ .
• Helium naturally agglomerates in the gaps in the matrix produced by bombardment and forms large defects, such as gap agglomerates or microbubbles 2 which remain stable at room temperature and can resist temperature increases up to at a few hundred ° C, for example up to 300 ° C.
• the device illustrated in FIG. 1 also includes a device for producing low-energy electrons 3, such as an electron gun, this device projecting an electron beam 4 onto one of the faces 5, called the rear face, of the matrix 1.
• Electrons in the electro beam pic 4 advantageously have an energy less than or equal to 20 keV, preferably between 1 and 5 keV.
• fluorescence of the target is induced from the front face 6 of the matrix, the emission of photons being represented by the arrows in wavy lines 7.
• the lamellar matrix 1 is in the form of a continuous strip, wound at one end in a reserve roll 20 and at its other end in a discharge roller 21.
• the matrix can be moved in the direction of arrow 22, by rotating said rollers 20 and 21, and bring before the electron beam a new part of the matrix not yet subjected to electron bombardment.
• This movement can be carried out manually or automatically, and it can be continuous or intermittent during the operation of the device according to the invention.
• the matrix is a bulk substrate 8.
• the implantation of the He ions is carried out in the same way as for the lamellar matrix 1, proceeding so as to obtain a maximum concentration of microbubbles 2 of He below a depth, preferably less than 5,000 ⁇ .
• the electron gun 3 projects a beam of low energy electrons onto the same surface as that by which the He ions have been implanted, and a fluorescence of the target is then induced through this surface 9, the emission of photons being represented by the arrows in wavy lines 10.
• We therefore have in this latter case what we will call an electronic bombardment of the front face of the matrix, as opposed to an electronic bombardment of the rear face of the matrix illustrated in FIG. 1.
• the device illustrated in FIG. 3 represents in a more detailed way a device implementing a electronic bombardment of the front face of the matrix.
• This device comprises an envelope 11 maintained under vacuum in which the matrix 8 is mounted on a support 12 which can be cooled by a cooling circuit 13, for example with water, in the event of use of the high intensity device.
• An electronic gun 3 emitting a beam of electrons with low energy and adjustable intensity is mounted on the envelope so as to direct this beam on the matrix.
• the angle of incidence between the beam and the plane of the matrix is calculated so that the emitted photons can propagate through the exit opening 14 formed at one of the front ends of the envelope 11.
• This end is provided with a flange 15 which is used to connect the device according to the invention to an apparatus in which ultraviolet light will be used.
• An electrical connection 16 makes it possible in particular to measure the electronic current in the matrix.
• An electronic screen 17 can be provided in the outlet opening 14 intended to prevent any exit of electrons through this opening, this electronic screen 17 then also being connected to the outside by an electrical connection 18.
• the casing 11 is maintained under vacuum, either by a pumping device, not shown, connected to the casing by the flange connection 19, or by the pumping device now holding the vacuum device, not shown, connected to the flange 15 .
• the matrix material must meet two main conditions: the insolubility of the gas in the matrix and relatively low absorption by the matrix of the gas emission continuum.
• the material of the matrix must preferably have optical properties such that the depth of escape of the photons produced is compatible with the depth of implantation. Therefore, the electron beam penetration depth need not exceed this photon escape depth and electron energies in the range of 0.1 to 20 keV are sufficient, even for surface bombardment before, with a relatively grazing incidence. This property of the photon source makes it possible to avoid the high costs necessary for carrying out high energy ionic and electronic bombardments, such as those used in known methods and devices. Excitement can be produced in particular by the use of a low energy electronic gun.
• the source is substantially planar and the surface and the shape of the source can be simply adjusted by structuring the electron beam.
• metals such as Sn, Mg, Al
• semiconductors such as Si, Ge or certain insulators.
• the emission depth of the source is very small, the source is substantially planar and the surface and the shape of the source can be simply adjusted by structuring the electron beam.
• an effectively point source can be obtained; by scanning or spreading the beam, it is possible to obtain an extended source compatible, for example, with the slit geometry used in certain spectroscopic work.
• a time-varying fluorescence intensity can easily be obtained by modulating the electron beam in pulses, which allows the use of the source in servo-control techniques (of the "lock in” type).
• the duration of existence of the fluorescence is less than 10 nsec.
• a source of Al / He-based photons is prepared in the manner described above and implemented according to the invention under an electron bombardment having an energy of 3800 V.
• This source produces, as shown in FIG. 4, a continuous spectrum of fluorescence which extends from 580 to 900 ⁇ , which is similar to what is obtained with conventional discharge sources.
• the production of photons from the matrix was compared with the synchrotron source SURF II and this compa reason indicates an efficiency greater than or equal to 10 -4 photons per electron. With sufficient electronic current, the brightness can reach that obtained by discharge lamps.
• photon source for example for photoelectronic spectroscopy in the ultraviolet, for studies of reflectivity, absorption and photoconductivity, etc.
• the source according to the invention can be incorporated into a large number of new, more complex systems.
• a) particle detectors by detecting the fluorescence induced in the device by the passage of charged particles.
• the methods and devices according to the invention have the advantage of not requiring differential pumping, gas replacement and cryogenic cooling. In addition, they are very easy to implement and flexible in operation.
• the source according to the invention offers the advantage of a brightness, which can vary by six orders of magnitude or differentiation, by modification of the intensity of the electron beam. It allows a specific geometry by concentration. Finally, its implementation is relatively inexpensive. It should be understood that the present invention is in no way limited to the embodiments described above and that many modifications can be made thereto without departing from the scope of this patent.

Landscapes

• Physical Or Chemical Processes And Apparatus (AREA)
• Physical Vapour Deposition (AREA)
• Particle Accelerators (AREA)
• Luminescent Compositions (AREA)

Priority Applications (1)

Applications Claiming Priority (2)

Publications (2)

Family

ID=19729876

Family Applications (1)

Country Status (6)

Families Citing this family (5)

• 1982
  • 1982-05-07 LU LU84136A patent/LU84136A1/fr unknown
• 1983
  • 1983-05-05 JP JP58501427A patent/JPS59500838A/ja active Granted
  • 1983-05-05 EP EP83901325A patent/EP0107686B1/de not_active Expired
  • 1983-05-05 US US06/576,386 patent/US4574198A/en not_active Expired - Fee Related
  • 1983-05-05 WO PCT/BE1983/000010 patent/WO1983004099A1/fr active IP Right Grant
  • 1983-05-05 DE DE8383901325T patent/DE3366001D1/de not_active Expired

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events