US2783385A - X-ray fluorescent spectrometry - Google Patents

X-ray fluorescent spectrometry Download PDF

Info

Publication number
US2783385A
US2783385A US389448A US38944853A US2783385A US 2783385 A US2783385 A US 2783385A US 389448 A US389448 A US 389448A US 38944853 A US38944853 A US 38944853A US 2783385 A US2783385 A US 2783385A
Authority
US
United States
Prior art keywords
crystal
rays
detector
circle
shaft
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
Application number
US389448A
Other languages
English (en)
Inventor
Wytzes Sjoerd
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Hartford National Bank and Trust Co
Original Assignee
Hartford National Bank and Trust Co
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Hartford National Bank and Trust Co filed Critical Hartford National Bank and Trust Co
Application granted granted Critical
Publication of US2783385A publication Critical patent/US2783385A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • 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
    • 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

  • This invention relates to an X-ray fluorescent analysis apparatus employing a focussing crystal.
  • Compounds of materials may be examined by X-ray techniques by exposing the same to X-ray so as to excite the elements thereof into a condition where they emit secondary X-rays having wavelengths which are characteristic of the nature of the elements. Thus, a poly-chromatic radiation is obtained which is characteristic of the material concerned. By measuring the wavelengths of this radiation and the associated intensities, the elements of the material and their proportions can be determined.
  • a single crystal plate For separating X-rays of equal wavelength from the poly-chromatic radiation, a single crystal plate may be employed in which the lattice planes are parallel or substantially parallel to the surface. The rays emitted by the material strike the crystal, and if the angle of incidence of the rays at the lattice planes corresponds to the so-called Bragg angle for a wavelength of the mixture of rays, reflection takes place and a beam of monochromatic X-rays of this wavelength is produced.
  • a transmission crystal plate may be employed, in which the lattice planes are at right angles or substantially at right angles to the surface, this plate being positioned relative to the rays emitted by the material such that the rays pass through the crystal.
  • the lattice planes deflect only rays of a definite wavelength, which strike the lattice planes at an angle at which the aforesaid Bragg formula is fulfilled.
  • a known apparatus of the foregoing type employs a focussing or curved single crystal for separating and in creasing the intensity of the various component wave lengths of the poly-chromatic fluorescent radiation.
  • the X-ray responsive detector is positioned along the arc of a circle, the center of which lies in the crystal surface, and is rotatable about that center along the arc of the circle.
  • the focussing crystal is rotatable about an axis through this center, parallel to the lattice planes and at right angles to the plane of the circle, the angular speed of the rotation of the crystal being half the angular speed of the detector.
  • a collimator is also provided between the material to be examined and the single crystal, so that direct rays are prevented from striking the detector.
  • the known apparatus suffers from the drawback that the are along which the detector is moved does not correspond to those positions at which the smallest sectional area, i. e. the focal spot, of the focussed beam of rays deflected by the crystal is located.
  • the known apparatus provides for continuously changing the radius of curvature of the focussing crystal for each position of the X-rays detector which neatent O" vide an apparatus of the foregoing type which eliminates the need for providing means for varying the curvature of the single focussing crystal as a function of the position of the detector.
  • the X-rays' falling at different angles on the curved crystal and de flected by reflection from the lattice planes will, in principle, converge to form line shaped images having cross sections located on the circumference of a circle defined by the curved crystal surface and having a diameter equal to the radius of curvature of the crystal, which will be referred to hereinafter as the measuring circle.
  • the detector is arranged to be rotatable about the center of this measuring circle.
  • the focussed X-ray spots Upon rotation of the curved crystal about its axis in the concave surface, which axis is at right angles to the plane of the measuring circle, the focussed X-ray spots will define a kind of cycloidal path.
  • Means are provided so that rotation of the detector about the center of the measuring circle will cause it to follow the same cycloidal path and, thus, always occupy the optimum position for receiving the X-rays, which involves rotating the detector with twice the angular speed of the crystal about its point of rotation, which moves with the crystal.
  • One embodiment of the apparatus according to the invention comprises a curved transmission crystal which is rotatable about a rotary shaft provided with an arm secured rigidly thereto having an extension pivotable about the free end of the arm.
  • the opposite end of the extension supports the detector, which is also guided by a slotted member which does not move with the rotation of the crystal.
  • the arm and extension have dimensions and are linked so that upon rotation of the crystal shaft, the angle between the arm and the extension is always double the angle through which the crystal has rotated.
  • the extension may be provided with a toothed wheel secured thereto and centered relative to the free end of the arm and engaging a stationary circular toothed rack, which is centered relative to the shaft about which the crystal rotates, the pitch circle of this toothed rack having twice the diameter of the toothed wheel. rack, use may be made of a combination of rope discs.
  • the detector is rotatably secured to the extension and is provided with a directional arm, which remains always orientated towards the rotary shaft of the crystal so that where the detector responds only to rays incident in a definite direction, the central rays of the deflected beams will be deflected in that direction.
  • Fig. 1 illustrates the principle of operation of the ap-" paratus according to the invention
  • Fig. 2 shows the cycloidal path described by the de- I tector
  • Fig. 3 shows diagrammatically one structural embodi for example, of quartz or mica, is positioned in the path Patented Feb-26, 1957.
  • This crystal has lattice planes-lying in the direction of thickness of the plate.
  • the initially flat plate is curved in a known manner such that these lattice planes are directed towards a point 8. h'l he pointed andthecurved crystal-define .a circle,
  • the points were the rays are deflected are dispersed in the transmission crystal 7 and not all of them lie on'the same circle going through the point 8. Although, therefore, the deflected rays are not focussed to a single point, they do form a beam, the sectional area-of which at the point 9 in the measuring circle is very small.
  • Rays having a different wavelength are united in beams which are deflected at different angles and converge to points distributed along the circle circumference- Their intensities may be measured, and then the whole X-ray spectrum may be scanned by displacing a detector 10 along the circumference of the measuring circle.
  • the angle-of incidence of the rays with the lattice planes may be varied by rotating the crystal 7 about a shaft 11 (Fig. 2) lying in the concave surface of the crystal, at right angles to the plane of the drawing and parallel to the lattice planes.
  • the portion of the specimen material surface 1-2 serving as a source of the rays to be measured may then be small, and provision may be made of a directional body 13, for example, a Seller slit collimaton'betweeii the surface of the material and the crystal in order to confine the range in which the detector 10 is struck by direct rays.
  • Fig. 3 illustrates one form of apparatus for achieving the desired relative motions.
  • the detector ll! is secured to an extension 15 of an arm 16 rigidly secured to a shaft 17, on which is seated the curved crystal '7.
  • the extension 15 is pivotably connected to the arm 16, and is adapted to rotate relative to this arm about a shaft 18.
  • the detector 10 which may be the conventional Geiger-Muller tube, has a cylindrical shape and is provided with a circular inlet window for the rays.
  • two diaphragms 23 and 24 In front of the window are provided two diaphragms 23 and 24, which are in turn provided with rectangular apertures.
  • the aperture 25 in the first diaphragm is shaped in the form of a narrow gap, parallel to the rotary shaft 17 of the crystal 7. This gap is located at the area where the beam of rays deflected and focussed by the crystal 7, and emitted by the object specimen surface 12, has its smallest sectional area.
  • the aperture 26 of the diaphragm 24 together with the gap 25 constitute a collimator for retaining stray rays.
  • the former is secured, together with the two diaphragms 23 and 24, to a directional arm 27, which is connected rotatably via a stud 28 to the extension 15 0f the arm 16.
  • the directional arm 29 is provided with an elongated slot 29, which engages the shaft 17 of the crystal 7.
  • An X-ray fluorescent analysis apparatus comprising a thin curved crystal for deflecting and converging to a point a mono-chromatic beam of X-radiation, said curved crystal having a given radius of curvature and defining a circle of diameter equal to said given radius, detecting means responsive to X-radiation located at said focal point of said X-ray beam to receive said X-radiation, first means for rotating said crystal about an axis extending therethrough at a given angular speed, and second means coupled to said first means for rotating said detecting means about an axis parallel to said crystal and passing through a point substantially at the center of said circle at twice the angular speed of rotation of said crystal;
  • An X-ray fluorescent analysis apparatus as claimed in claim 1, wherein said second means includes a pair of arms pivotable about a common shaft, one of said arms being secured to said crystal, the other of said arms being secured to said detector, said common shaft passing substantially through the center of said circle.
  • An X-ray fluorescent analysis apparatus comprising a thin curved focussing transmission crystal for deflecting and converging to a point, a mono-chromatic beam of X-radiation, a rotary shaft supporting said crystal, said curved crystal being rotatable about said rotary shaft and having a given fixed radius of curvature and defining a measuring circle having a diameter substantially equal to that of said given radius, detecting means responsive to X-radiation located approximately at the focal point of said X-ray beam to receive said X-radiashaft and rotatable therewith, 'a stationary first rotary disc aligned with said rotary shaft, an extension pivotably 5 connected at a pivot point to the other end of said arm and secured to said detector, a second rotary disc rigidly secured to said extension and aligned with said pivot point, and means for rotating said rotary shaft, said first and second rotary discs co-operating to impart a rotation to said detector about said pivot point at an angular speed twice the angular speed of said rotary shaft
  • An X-ray fluorescent analysis apparatus as claimed in claim 3 in which the first rotary disc is a toothed wheel and the second rotary disc is a toothed rack in engagement with said toothed wheel, the diameter of the pitch circle of said toothed wheel being half that of said toothed rack.
  • An X-ray fluorescent analysis apparatus as claimed in claim 3 in which the detector is rotatably secured to said extension, and a. directional arm having a slotted aperture engaging the rotary shaft is secured to said detector to insure that the detector is always properly oriented to said crystal.
  • An X-ray fluorescent analysis apparatus as claimed in claim 3 in which the detector includes a collimating slit located at the focal spot of the X-ray beam and a Geiger-Muller tube for receiving the radiation passing through said slit.

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)
US389448A 1952-11-08 1953-10-30 X-ray fluorescent spectrometry Expired - Lifetime US2783385A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
NL316826X 1952-11-08

Publications (1)

Publication Number Publication Date
US2783385A true US2783385A (en) 1957-02-26

Family

ID=19783831

Family Applications (1)

Application Number Title Priority Date Filing Date
US389448A Expired - Lifetime US2783385A (en) 1952-11-08 1953-10-30 X-ray fluorescent spectrometry

Country Status (7)

Country Link
US (1) US2783385A (zh)
BE (1) BE524089A (zh)
CH (1) CH316826A (zh)
DE (1) DE1027903B (zh)
FR (1) FR1090233A (zh)
GB (1) GB741854A (zh)
NL (2) NL85501C (zh)

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2835820A (en) * 1955-03-07 1958-05-20 Jr La Verne S Birks Curved crystal fluorescent x-ray spectrograph
US2898469A (en) * 1956-09-11 1959-08-04 Gen Electric X-ray diffraction apparatus
US2957079A (en) * 1957-12-27 1960-10-18 Gen Electric Penetrating ray emission coding
US2958776A (en) * 1957-09-11 1960-11-01 Vickers Electrical Co Ltd Mechanical linkages
US3012443A (en) * 1960-01-11 1961-12-12 Patent Man Inc Mechanical movement for translating rotary motion to linear motion
US3031571A (en) * 1956-05-21 1962-04-24 Well Completions Inc Apparatus and method for conditioning and analyzing earth components
US3073952A (en) * 1956-09-11 1963-01-15 Gen Electric X-ray diffraction apparatus
US20150177167A1 (en) * 2013-12-24 2015-06-25 Hitachi High-Tech Science Corporation X-ray fluorescence analysis apparatus

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4199678A (en) * 1979-01-31 1980-04-22 U.S. Philips Corporation Asymmetric texture sensitive X-ray powder diffractometer
DE3125803A1 (de) * 1981-06-30 1983-01-13 Siemens AG, 1000 Berlin und 8000 München Kristall-roentgen-sequenzspektrometer
JP3531098B2 (ja) * 1998-12-28 2004-05-24 理学電機工業株式会社 蛍光ｘ線分析装置

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2532810A (en) * 1950-01-13 1950-12-05 Gen Electric X-ray diffraction apparatus for use with radioactive materials
US2540821A (en) * 1949-04-19 1951-02-06 Gen Electric X-ray spectrometer
US2578722A (en) * 1950-05-18 1951-12-18 United States Steel Corp Apparatus for determining coating thickness

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2540821A (en) * 1949-04-19 1951-02-06 Gen Electric X-ray spectrometer
US2532810A (en) * 1950-01-13 1950-12-05 Gen Electric X-ray diffraction apparatus for use with radioactive materials
US2578722A (en) * 1950-05-18 1951-12-18 United States Steel Corp Apparatus for determining coating thickness

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2835820A (en) * 1955-03-07 1958-05-20 Jr La Verne S Birks Curved crystal fluorescent x-ray spectrograph
US3031571A (en) * 1956-05-21 1962-04-24 Well Completions Inc Apparatus and method for conditioning and analyzing earth components
US2898469A (en) * 1956-09-11 1959-08-04 Gen Electric X-ray diffraction apparatus
US3073952A (en) * 1956-09-11 1963-01-15 Gen Electric X-ray diffraction apparatus
US2958776A (en) * 1957-09-11 1960-11-01 Vickers Electrical Co Ltd Mechanical linkages
DE1131428B (de) * 1957-09-11 1962-06-14 Vickers Electrical Co Ltd Fuehrungsgestaenge fuer ein Roentgenspektrometer
US2957079A (en) * 1957-12-27 1960-10-18 Gen Electric Penetrating ray emission coding
US3012443A (en) * 1960-01-11 1961-12-12 Patent Man Inc Mechanical movement for translating rotary motion to linear motion
US20150177167A1 (en) * 2013-12-24 2015-06-25 Hitachi High-Tech Science Corporation X-ray fluorescence analysis apparatus
US9645100B2 (en) * 2013-12-24 2017-05-09 Hitachi High-Tech Science Corporation X-ray fluorescence analysis apparatus

Also Published As

Publication number Publication date
CH316826A (de) 1956-10-31
DE1027903B (de) 1958-04-10
BE524089A (zh)
FR1090233A (fr) 1955-03-29
NL173668B (nl)
NL85501C (zh)
GB741854A (en) 1955-12-14

Similar Documents

Publication Publication Date Title
US2540821A (en) X-ray spectrometer
US4446568A (en) Versatile focusing radiation analyzer
US2783385A (en) X-ray fluorescent spectrometry
JPS6020139A (ja) Ｘ線分析装置
JP3712531B2 (ja) Ｘａｆｓ測定方法及びｘａｆｓ測定装置
US2805342A (en) Diffractometer
US2805341A (en) Diffractometer
US3160747A (en) X-ray analysis apparatus comprising a fixed detector means and plural interchangeable analyzing crystals
US3566111A (en) Apparatus for varying the detector slit width in fully focusing x-ray spectrometers
US4199678A (en) Asymmetric texture sensitive X-ray powder diffractometer
US4580283A (en) Two-crystal X-ray spectrometer
US3073952A (en) X-ray diffraction apparatus
US2805343A (en) Diffractometer
US3005098A (en) X-ray emission analysis
US3124681A (en) Zingaro
US2528521A (en) Radiographic unit
US3486021A (en) Goniometer for x-ray diffraction apparatus
US3213278A (en) X-ray spectrograph having plural detectors
US3304427A (en) X-ray beam defining apparatus having adjustable collimator plates disposed in three parallel planes
US3906225A (en) X-ray spectrometer
US5115460A (en) X-ray analysis apparatus comprising an adjustable slit diaphragm
US3200248A (en) Apparatus for use as a goniometer and diffractometer
US3427451A (en) X-ray diffractometer having several detectors movable on a goniometer circle
US2666147A (en) Spectrometer
US3614425A (en) X-ray diffraction apparatus comprising a curved spectroscopic crystal with a rotatable x-ray slit at the focus thereof