US3857038A - Glow-tube for x-ray spectrometry with directly excited samples - Google Patents
Glow-tube for x-ray spectrometry with directly excited samples Download PDFInfo
- Publication number
- US3857038A US3857038A US00318198A US31819872A US3857038A US 3857038 A US3857038 A US 3857038A US 00318198 A US00318198 A US 00318198A US 31819872 A US31819872 A US 31819872A US 3857038 A US3857038 A US 3857038A
- Authority
- US
- United States
- Prior art keywords
- tube
- glow
- anode
- cathode
- casing
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
- 238000000441 X-ray spectroscopy Methods 0.000 title claims abstract description 8
- 229910052751 metal Inorganic materials 0.000 claims description 6
- 239000002184 metal Substances 0.000 claims description 6
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 claims description 6
- 238000010894 electron beam technology Methods 0.000 claims description 5
- 229910052697 platinum Inorganic materials 0.000 claims description 3
- 229910052702 rhenium Inorganic materials 0.000 claims description 3
- WUAPFZMCVAUBPE-UHFFFAOYSA-N rhenium atom Chemical compound [Re] WUAPFZMCVAUBPE-UHFFFAOYSA-N 0.000 claims description 3
- 229910052703 rhodium Inorganic materials 0.000 claims description 3
- 239000010948 rhodium Substances 0.000 claims description 3
- MHOVAHRLVXNVSD-UHFFFAOYSA-N rhodium atom Chemical compound [Rh] MHOVAHRLVXNVSD-UHFFFAOYSA-N 0.000 claims description 3
- 238000007789 sealing Methods 0.000 claims description 3
- 238000004458 analytical method Methods 0.000 abstract description 6
- 238000012916 structural analysis Methods 0.000 abstract description 3
- 230000005540 biological transmission Effects 0.000 description 4
- 230000005855 radiation Effects 0.000 description 4
- 239000000203 mixture Substances 0.000 description 3
- 230000000644 propagated effect Effects 0.000 description 3
- 230000004907 flux Effects 0.000 description 2
- 150000002500 ions Chemical class 0.000 description 2
- 238000004611 spectroscopical analysis Methods 0.000 description 2
- 238000001228 spectrum Methods 0.000 description 2
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 1
- 229910000831 Steel Inorganic materials 0.000 description 1
- 230000004075 alteration Effects 0.000 description 1
- 239000004411 aluminium Substances 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 239000004020 conductor Substances 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 238000007872 degassing Methods 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000005684 electric field Effects 0.000 description 1
- 230000003628 erosive effect Effects 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 238000001465 metallisation Methods 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 230000003071 parasitic effect Effects 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 239000008188 pellet Substances 0.000 description 1
- 239000010959 steel Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
Images
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J35/00—X-ray tubes
- H01J35/02—Details
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N23/00—Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups G01N3/00 – G01N17/00, G01N21/00 or G01N22/00
- G01N23/22—Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups G01N3/00 – G01N17/00, G01N21/00 or G01N22/00 by measuring secondary emission from the material
- G01N23/223—Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups G01N3/00 – G01N17/00, G01N21/00 or G01N22/00 by measuring secondary emission from the material by irradiating the sample with X-rays or gamma-rays and by measuring X-ray fluorescence
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J3/00—Details of electron-optical or ion-optical arrangements or of ion traps common to two or more basic types of discharge tubes or lamps
- H01J3/02—Electron guns
- H01J3/021—Electron guns using a field emission, photo emission, or secondary emission electron source
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J35/00—X-ray tubes
- H01J35/02—Details
- H01J35/20—Selection of substances for gas fillings; Means for obtaining or maintaining the desired pressure within the tube, e.g. by gettering
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2223/00—Investigating materials by wave or particle radiation
- G01N2223/07—Investigating materials by wave or particle radiation secondary emission
- G01N2223/076—X-ray fluorescence
Definitions
- Tubes used for X-ray spectrometry include ones which operate in a deep vacuum, of about 10 mm Hg,
- Vacuum tubes with a heated filament require a deepvacuum installation, and emitting efficiency is low, because of the electrical energy expended in detaching the electrons from the filament.
- These fluorescent tubes are either sealed, with a slit, or can be dismantled to allow the sample to be inserted into the vacuum chamber.
- the presence of the slit prevents the passage of retrodiffused electrons and soft X-photons with a long wavelength, needed to analyse elements with low atomic weight, while the need to place the sample in a vacuum enclosure means that only materials which will not produce degassing can be analysed.
- the sample, acting as anode is exposed to intense bombardment by electrons, and can begin to melt, altering its surface composition.
- glow-tubes with a cold cathode emitting a mixture of electrons and hard X-rays, and with no slit, which operate in a partial vacuum of 10 to 10' mm Hg, comparable to the vacuum prevailing in v a spectrometry chamber.
- Exciting of the sample comes from a mixed source, since it receives a simultaneous beam of X-rays and electrons retrodiffused by the anode. During this retrodiffusion, ions are removed from the anode metal and deposited on the sample.
- This metal-coating effect is a disadvantage, creating a film which absorbs the X-rays emitted by the sample, and distorting the results of spectrometric analysis.
- at short wavelengths and large amounts of energy transmitted to the sample and needed to excite its characteristic lines could damage substances affected by heat.
- the present invention concerns a glow-tube without a slit, which overcomes these drawbacks, emitting electrons directly, and with high efficiency. More specifically, it concerns a tube containing a cathode consisting of a metal disc, and a grid-shaped anode, both electrodes being located in the axis of the tube, with an opening on the same axis behind the anode, through which the electron beam is propagated by inertia, in the direction of the target.
- the tube defined in this invention allows a sample to be excited directly, by direct emission of electrons, without any photons.
- the energy spectrum of direct, non-retrodiffused electrons is narrower than for retrodiffused electrons, so that energy is saved, since the flux needed to excite any line in the sample is much smaller. This ensures much higher emission efficiency, and prevents damage to the sample from heat.
- the anode is in the form of a grid, so that the sam plc is not exposed to any direct trajectory starting at the wires of the anode grid receiving the electron impacts.
- the tube described in the invention ensures high emission efficiency, up to in contrast to conventional fluorescent tubes (the ratio of energy absorbed to energy emitted is approximately 10 Compared with existing direct-emission tubes, it offers many advantages, operating without a deep vacuum, in a partial vacuum of approximately l0" to 10 mm Hg; and since the sample does not form part of the electronic optical system, it need not be a conductor.
- the use of a grid-shaped anode offers many advantages. Its role is to attract the electrons in the direction of the tube-casing axis, and allow the electron beam to pass through the grid without loss of energy.
- the electrical field set up between the cathode and anode results only from the potential between them and, in the absence of any conducting body in the space through which this beam passes, radiation is perfectly rectilinear and trajectories are parallel. This means that the surface even of a large'sample is subjected to uniform radiation, preventing localized temperature rises that could damage the surface.
- the electrons are propagated in a parallel beam, so that their velocities are not subject to localized variations. Since the energy spectrum emitted is narrow, the exciting efficiency for a characteristic line remains high.
- Choice of the transmission coefficient of the grid allows the intensity of the radiation flux to be controlled for a given amount of electrical energy, notably if there is a possibility of heat damaging the sample.
- Choice of the surface-area of the grid allows it to be adapted to the size. of the samples being subjected to radiation, without altering the electrical. and energy characteristics of the beam emitted;
- the tube described in the invention thus allows great versatility in the use of equipment, which is also dependent on a fixed energy-supply source.
- FIG. 4 shows a tube according to the present invention attached to a base for mounting it in a spectrometer.
- FIG. 1 shows, in diagrammatical form, the positioning of the electrodes inside the insulating casing 1.
- the cathode 2 is a disc or pellet made from metal with a high electron-emitting capacity and good resistance to ionic erosion, such as aluminium.
- the anode 3 is a metal-grid made from rhodium, rhenium or platinum, and connected to earth.
- the electron beam 4 emitted by the cathode travels towards the anode, and is propagated by inertia in the direction of the sample 5 placed in its path.
- the X-ray beam emitted by the sample following exciting of the characteristic lines of the elements of which it is formed, is then treated by standard spectrometric methods, using a collimator, crystal and meter, arranged as a goniometer.
- FIG. 2 shows the constructional details of the tube, according to a recommended embodiment of the invention.
- the casing is in two parts (1a and lb), which slide inside each other.
- a cathode 2 fixed to a threaded rod 6, the length of which can be adjusted and which is held by nuts 7 in the end of the casing.
- the electrical connections 8 are placed inside a flexible insulating covering 9.
- the cathode rod may be attached to a radiator with cooling fins.
- the outer casing lb has an anode 3 near the end, in the form of a grid connected with earth, with a ring 10, which holds it in a groove on the inner surface of the casing.
- the otuer casing has a capillary inlet pipe 1 1 through which an adjustable flow of gas can be fed in, and the inner casing has an outlet 12, so that pressure inside the tube can be kept constant or vary.
- An O-ring 13 between the two casings ensures proper sealing.
- the distance between the electrodes can be adjusted by sliding cent tube with the slit 16 in a transverse direction in relation to the axis of the tube 1 and its cylindrical base 17.
- the surface 18 provides a seal during fitting to a spectrometer.
- the tube described in the invention can be used not only for X-ray spectrometric analysis, but also for structural analysis by diffraction (lattice of a crystalline phase or the structure of a liquid) or by scattering (measurement of the dimensions of particles, mixtures, etc.).
- a glow-tube for use in X-ray spectrometry with directly excited samples, said glow-tube comprising at least one elongated insulating casing having an opening in one end thereof and containing a disc-shaped cathode and a grid-shaped anode, said cathode and anode being aligned longitudinally of said casing with said anode between said cathode and opening, said tube being adapted to propagate an electron beam which passes through said opening when said cathode is connected to a high voltage source and said anode is connected to ground.
Landscapes
- Physics & Mathematics (AREA)
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Chemical & Material Sciences (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- General Physics & Mathematics (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Analysing Materials By The Use Of Radiation (AREA)
- X-Ray Techniques (AREA)
- Luminescent Compositions (AREA)
- Lasers (AREA)
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
FR7147290A FR2166539A5 (pt) | 1971-12-29 | 1971-12-29 |
Publications (1)
Publication Number | Publication Date |
---|---|
US3857038A true US3857038A (en) | 1974-12-24 |
Family
ID=9088303
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US00318198A Expired - Lifetime US3857038A (en) | 1971-12-29 | 1972-12-26 | Glow-tube for x-ray spectrometry with directly excited samples |
Country Status (23)
Country | Link |
---|---|
US (1) | US3857038A (pt) |
JP (1) | JPS4881585A (pt) |
AR (1) | AR193002A1 (pt) |
AT (1) | AT346434B (pt) |
AU (1) | AU467584B2 (pt) |
BE (1) | BE793443A (pt) |
BR (1) | BR7209161D0 (pt) |
CA (1) | CA994480A (pt) |
CH (1) | CH569362A5 (pt) |
CS (1) | CS174866B2 (pt) |
DD (1) | DD102860A5 (pt) |
DE (1) | DE2264191A1 (pt) |
ES (1) | ES410109A1 (pt) |
FR (1) | FR2166539A5 (pt) |
GB (1) | GB1409309A (pt) |
HK (1) | HK14077A (pt) |
IL (1) | IL41186A (pt) |
IT (1) | IT972979B (pt) |
LU (1) | LU66756A1 (pt) |
NL (1) | NL7217759A (pt) |
NO (1) | NO139394C (pt) |
OA (1) | OA04232A (pt) |
ZA (1) | ZA729131B (pt) |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CS268377B1 (en) * | 1988-04-08 | 1990-03-14 | Emil Ing Vratnicek | Electron gun for electron microscope |
Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2521656A (en) * | 1945-12-13 | 1950-09-05 | Emilio G Segre | Ionization chamber |
US3118064A (en) * | 1961-08-30 | 1964-01-14 | Frank H Attix | New type of free air ionization chamber |
US3373283A (en) * | 1963-06-11 | 1968-03-12 | Commissariat Energie Atomique | Device for triggering a nuclear particle detector of the gas type |
US3601612A (en) * | 1969-08-22 | 1971-08-24 | Atomic Energy Commission | Wire spark chamber with magnetostrictive readout |
US3681600A (en) * | 1969-10-24 | 1972-08-01 | Perkin Elmer Corp | Retarding field electron spectrometer |
-
0
- BE BE793443D patent/BE793443A/xx unknown
-
1971
- 1971-12-29 FR FR7147290A patent/FR2166539A5/fr not_active Expired
-
1972
- 1972-12-13 OA OA54779A patent/OA04232A/xx unknown
- 1972-12-25 JP JP48004561A patent/JPS4881585A/ja active Pending
- 1972-12-26 US US00318198A patent/US3857038A/en not_active Expired - Lifetime
- 1972-12-27 LU LU66756A patent/LU66756A1/xx unknown
- 1972-12-27 BR BR9161/72A patent/BR7209161D0/pt unknown
- 1972-12-27 AR AR245866A patent/AR193002A1/es active
- 1972-12-27 IL IL41186A patent/IL41186A/en unknown
- 1972-12-28 NO NO4811/72A patent/NO139394C/no unknown
- 1972-12-28 AU AU50557/72A patent/AU467584B2/en not_active Expired
- 1972-12-28 ES ES410109A patent/ES410109A1/es not_active Expired
- 1972-12-28 CH CH1893772A patent/CH569362A5/xx not_active IP Right Cessation
- 1972-12-28 NL NL7217759A patent/NL7217759A/xx not_active Application Discontinuation
- 1972-12-28 CA CA160,017A patent/CA994480A/fr not_active Expired
- 1972-12-28 DD DD167954A patent/DD102860A5/xx unknown
- 1972-12-28 ZA ZA729131A patent/ZA729131B/xx unknown
- 1972-12-28 GB GB5978772A patent/GB1409309A/en not_active Expired
- 1972-12-28 IT IT33655/72A patent/IT972979B/it active
- 1972-12-29 AT AT1116072A patent/AT346434B/de not_active IP Right Cessation
- 1972-12-29 DE DE2264191A patent/DE2264191A1/de active Pending
- 1972-12-29 CS CS9062A patent/CS174866B2/cs unknown
-
1977
- 1977-03-24 HK HK140/77A patent/HK14077A/xx unknown
Patent Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2521656A (en) * | 1945-12-13 | 1950-09-05 | Emilio G Segre | Ionization chamber |
US3118064A (en) * | 1961-08-30 | 1964-01-14 | Frank H Attix | New type of free air ionization chamber |
US3373283A (en) * | 1963-06-11 | 1968-03-12 | Commissariat Energie Atomique | Device for triggering a nuclear particle detector of the gas type |
US3601612A (en) * | 1969-08-22 | 1971-08-24 | Atomic Energy Commission | Wire spark chamber with magnetostrictive readout |
US3681600A (en) * | 1969-10-24 | 1972-08-01 | Perkin Elmer Corp | Retarding field electron spectrometer |
Also Published As
Publication number | Publication date |
---|---|
NO139394C (no) | 1979-02-28 |
HK14077A (en) | 1977-04-01 |
DE2264191A1 (de) | 1973-07-05 |
ES410109A1 (es) | 1975-12-16 |
GB1409309A (en) | 1975-10-08 |
ZA729131B (en) | 1973-11-28 |
BE793443A (fr) | 1973-04-16 |
CA994480A (fr) | 1976-08-03 |
OA04232A (fr) | 1979-12-31 |
AR193002A1 (es) | 1973-03-21 |
CH569362A5 (pt) | 1975-11-14 |
ATA1116072A (de) | 1978-03-15 |
FR2166539A5 (pt) | 1973-08-17 |
IL41186A0 (en) | 1973-02-28 |
AT346434B (de) | 1978-11-10 |
AU5055772A (en) | 1974-07-04 |
IT972979B (it) | 1974-05-31 |
DD102860A5 (pt) | 1973-12-20 |
AU467584B2 (en) | 1974-07-04 |
LU66756A1 (pt) | 1973-02-27 |
JPS4881585A (pt) | 1973-10-31 |
IL41186A (en) | 1976-04-30 |
NO139394B (no) | 1978-11-20 |
CS174866B2 (pt) | 1977-04-29 |
NL7217759A (pt) | 1973-07-03 |
BR7209161D0 (pt) | 1973-09-25 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US4075526A (en) | Hot-cathode x-ray tube having an end-mounted anode | |
Oliphant | The liberation of electrons from metal surfaces by positive ions. Part I.—Experimental | |
Dos Santos et al. | Development of portable gas proportional scintillation counters for x‐ray spectrometry | |
Mattson et al. | The application of a soft X-ray spectrometer to study the oxygen and fluorine emission lines from oxides and fluorides | |
US4701941A (en) | Radiation source | |
US2720593A (en) | Scintillation-type ion detector | |
US3857038A (en) | Glow-tube for x-ray spectrometry with directly excited samples | |
Samson et al. | Duoplasmatron as a vacuum ultraviolet light source | |
Ahlberg et al. | Experimental comparison of photon‐and particle‐induced X‐ray emission analysis of air particulate matter | |
US3011060A (en) | X-ray spectrograph | |
DOWbING et al. | COUNTERS FOR X;. RAY ANALYSIS | |
JPH0756781B2 (ja) | 中空陰極放電管 | |
Alexander et al. | Characterization of a saddle-field discharge gun for FABMS using different discharge vapours | |
US6617771B2 (en) | Electron ionization ion source | |
US2347424A (en) | X-ray tube | |
Mori et al. | Photoelectric emission of metals by x-rays in the keV region | |
Luggar et al. | Electronically gated multiemitter x-ray source for high-speed tomography | |
Palmer | Recent advances in gas scintillation proportional counters | |
Duan et al. | Characterization of an improved thermal ionization cavity source for mass spectrometry | |
RU2291469C1 (ru) | Газовый пропорционально-сцинтилляционный детектор | |
Dershem | A Shielded Filament X‐Ray Tube for Pure X‐Ray Spectra | |
US3435211A (en) | Gaseous glow discharge tube with cathode means surrounding anode means | |
US3143679A (en) | Focussing arrangement for X-ray tubes | |
Machlett | An Improved X‐Ray Tube for Diffraction Analysis | |
Acar et al. | Experiences on production-usage reasoned malfunctions & development of X-ray tubes used in science and their effects on sediment measurements |