DE1523079A1 - Method and device for determining elements, in particular for determining and determining elements by means of X-ray fluorescence analysis - Google Patents

Description

PATENT ADVOCATE DIPL-ING. ERICH SCHUBERT

Abi. Patent attorney Dipl.-Ina. SCHUBERT, 9 Sicgtn (WhH.), Poitfodi325 OraniwMtrae 14

64 012 üe / 's ofam

A COO Λ 7 Q

I OtOU / v3

T * l «feni 23102 TfUgramnvAdr.i Patschub, Sitgen

PottKtocfckonteni Cologne ICK »», Emmi 203ä

■ anktarfWi

DwttdM fcwlk AO.,

rilitlwi Si * g * n u.Ob * rhaui «n (RhId.)

United kingdom Atoinio Energy Authority, Patents Branch, 11-12, Charles II Street, London, SVH, England

For this application priority is derived from British patent application IFr. 1012/63 of January 9, 1963 claimed. Jt

Method and device for determining elements, in particular for determining and determination of elements by means of Hont genstraiu .en-. fluorescence analysis.

The invention relates to the determination and determination of elements, in particular a \: f the determination and Determination or etching of elements by means of Ron ;; gene-radiation-F-fluorescence analysis / X-ray fluorescence analysis /.

The liquidity of the Höntgenstrah.Lexi-ji ¹ luoresü32izana.l. / Se

BATH ORIGINAL

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is sometimes di.roli interele-nent-L. feicbe /i.Mter-ej.biuuut exx'eo '^ j / very limited, the most important dissar effect is the lviatrix absorption effect / "matrix absorption" effect /, in which the intensity of the characteristic X-rays from an element, its concentration is determined or determined ./ird (iui the following uiit "gesuoiites LLerneut" denote ^, diu / oh ^ Ine Zunaiime of the concentration ei.es aucier-ai .oj.emeutia -, vfejci..ej "u Lachst - slienuen i.iit" I ^ 'sert'e. -Enzele-iient "denotes .vira-verri -'-'- tfer L v / ir;., Desseii j-adsöiiaosorotioiiükofef .'iaieu'':;;! - uei u-jti in . consideration ku, uüni: iden ^ _{uer_;;} i3u / euü: & 1β3 o ± i.it ^ rist j-calibration zj / in comparison to that of the ^ ori ^ -m ia, -; rix aiiid uer "verstärkuiigseffer;;.! "/"iiia.trIx eiui ^ iioaiaeiit" ei 'ect / -.rzüu _e jtä: Li; .e der I..tj. -lität der Röntgengei ·. jtraiixen von daa

: .er infox ^ e of the inner A ± c? e .-; O.ur / iiJ) .vueij. duron rested the i-Lörisgensi & hxen of i_j.t ^ ri ^v erenzelementes; my iiöntgona. Since in the I.iehrzaiij. uer jj ^l nlle the i..atrIa- / erstaritiuigjüefifekt iiii comparison z \ '. iü! ». atrix-Absorptionsefx'eiCt ü> v-ruauhx ..ssigen is the I; e"to-Sna'.:; rix8fle ^: t a soxcliar of the ausorotion, and the amplification effects can be used for dis ueisteii purposes for eight different purposes.

As J? Oj-ge this lietto-absorption sejrx'eKtes niuuut .iij-Uoreuzenz-Hnntgenstrahleii-lnteixyit i ^J j from the healthy clem with increasing concentration of the inference exemented iu ..er luatrix to. domit h.:n ^ t the intensity; the jj'xuoreszeiiZ-lLÖntgieustraße does not depend on the concentration of the searched jjeaentea aixein, but is also dependent on the concentration of the inferred element. _BATH

. 909830/1150

The purpose of the "- <; rfi. · Κ1λι.ι £ is the ociiaffuiig of a process -. ■■ ία a Yo rri ch hung χ ir die tfiiroreszenz-Rontgenstranj-enanod./se, in which or which the Iiiferelei.ie. ..- t-iSffeicte he'biiüi- are reduced or completely switched off.

The invention is a development of the i ^ -uorescence-Röiitßensirah-ie '&na.; yse for the determination ¹ : the concentration ei es. 'esuoiiten element in a jcterial, the sion follow from the 7erffc, lireij.3st., fen zasauuiiens;

Üibntgens "rails are passed into a sample from the ha eriax uü-dj 'gesühiclct, vvc.uinjö contains the sought-after -uxeiüeirc; from the EÖiitgens;: rah.i.en, which are scattered back from the sample, v / ground The fluorescent X-ray str, iiieii the element sought iso.iiertj the intensity (Im) of these fluorescent X-ray stralils and the intensity (Im) ^ sr passed through the sample! d- \ s "Verlil.Ltnis I" to I, "or a multipliJfcative .cation of I-, or I ^ against the (or relative to) concentration. of the element sought, the concentration of the element sought is determined again practically free of inter-element effects.

In addition, a device for the fluorescence X-ray radiation, which has a radiation source, and a detector for back-generated reflections, is created - ■ $ shine, means for a Jt'iuoreüz-Höntgeiistrahle-n-energy selection, a detector for

BATH ORIGINAL

909830/1150

"•; ransinittierte or transferred. ..E Roiitge .-. Jsti'au-. En unu. It" ^1. , El zviii π; α .. 'ce: i der zc. aii & j. 'si3rej.10.en sample.

The erfi.ad.-UrSsge.ui? E / orriohtvng niai. ·.,! au oh a ho .. ijaator zr .Creation of a scn: iia.-en ray (enbünuei) s oruusiUi he t ü iert gens ττ ah j. en avf white.

The j.-itte. '.. fr <.i.ie HUv.ores ^ eiiZ
. ■ iuswahi grains a..s a .- "a, ar jjiffereiitia.,. Fixter & \ .3 _L .ebiidet, which are two separate JPiIt ^ r, one of which is effectively av.roh.Lt.ssig for aie ^ liLoreszexiZ-liöncgenstrari-ien from the gesovii-!; en 'i-eiuent vnd der tu j the e effectively üxid ^ jirciu-üssi, ;; / opt-que / · ist. Vorzv.gsv / eise are the i ^ ateriai.ien, uas ae ... en the j'ixter hergescelj.t, so certain that'i only aiix en ^ er ^ ner ^ iebreiuh aiej.j. ao3ürp ': ionsicanT, en der i ^{< l} i

It is jedooh hingewivsen that aie i.iittel for ■ ^{ö'.i.uoresüenz-Wöntgens:} rah - enausvvah.L not necessarily a ± ^J aa.r Differentiaj.filter must be iaog_.iche Other methods aer Höntgenstrah-s-en-xinersieaiiswahi consist in the use of a entweaer ivristaii spectrometer (this is only / ER. ^rr endv_ng a Rö.ntc-instrahi Engener at or mögxloh s), a single-Hoixtgenatrah .enfij.ters, a eriergieeiapfindiiohen detector, which stands with aer liapulsliöhenanalyse in / eroinuwig, or something like that.! without selecting. ief he ^ uei. ' e and detector that only the he-.i'ürderiiohe Höntgeiistrahj. zur -tüire ^ i.ai .. ·; ^ e or eight and is determined »

BAD ORiGiMAL

909830/1150

_5-

- ^ ie -rf indung so ...... mmmanr ü

j3estijiL..LiLii {j oaer jj'esas;& 1. ·. n ~ from him. ύί 1t irtv / er de. ι.

^ ßaz: g on in is.enwarx of

iJiö otrah.ieni.ief erci "j'.ü.i ... 3 _t y / eiohe fi'r di; fluorescent Hönj ^ enstrah. en from deüi ^ s ^. used v / ird, sox ... te under i
Si-Jhtspunkfce auotjew '.h. Is:

^ xuj. ■ from

e-

1. Vw the iC-X-ray _i; ; enscrah-en des esv.onjöx ^ - ^. e ^

(eg «iLupfer) to reach-, eiL, α, Λΐβ uie x ^ ier ^ ie der diran.enfi :: eL ο larger;. ,, '_ ■.: s die 2nerijie aer ..- Abso -." p _:: aes iojiSiCcüa.te ei es..LC ¹ it s ^ .erneutes be (ϊ r x .. .ox'er they iat c, 9 - ^ etj.

2. i'Lir j, axi% il-. ^ iatuu jsfuhi ^ lceit ba './. -Wirkun-3.- ₃ ra.a - id die i> bra.hj.ena "-. e.; .. eienei \: ie so iiiedriij as Jio ^ 'j-iuii & 3in, v / - ^: .iirend die jtieaing'L; *: ^ (1) jedouh oefoj. ^ L uz ·. · :, eix ^ ehaltsn v / ird.

5. -U ^{1 For} an axxinal scattering, -i · e 6 .raiLLenii.ej— enenergy must be as low as possible.

A fourth limitation, however, is given by the requirement that the intensity of the transmitted radiation must be determined, it being necessary that I m should not be too low for an accurate measurement.

In practice there are several sources of radiation available

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and ζ..ar an idöritgenstrah. angonerator (uer eine v.; i η der iche --asrgia ergiüt) and Radioisotooenouex. en, rfie Delüoic'-Sweiue - ^J roiiiethiuiii 147 / A-.wuiniiiJii (1u-6ü .e / efx'eiciv), ^ üierxci- iu-241 (11-22 and 60 kaY effective), l'ritiusi / "Zirkoni - m and Tritium .. Titaniuu (ö, 93 - 12 keV effective) -.aid οα.αωΐ. ^ - 1ΐ; 9 C <: 2 .-. c / ef:. 'eict Proriexüi: u! i-147, ----> iiiiui! 'm' ..na Λίώβΐϋϊ'ΛΕϊ 241 icöatiien aioh used. ■ lerdeii., er ^ eoen siber Dei low :! iarpferkonzen ^ ratioiifcjivvvi ^ the low ^ mission av.s aiesen ά ^ ηάύ.ΰ ^ ·,. & 1 len. Whose vert / j, .. · '! - ny doniit is üadmii> m-109 which vc / r ^ ezogeiie , -süu, aoon aau _;; .jueriji: u-241 eoenso be used lia is ersichtlioli, _f DAT for .. · Jaüuiiun-109 Lrre; ungsenergie (2 ^) mid transmitted Lner _o ie (ώ +) GL: are iioneri, je-dojh in J = -e al vn A, .eriüir.jx-241 ^v '_ · nü i'. efiecbiv be different iCömiten, η ... ΐΛ i eg »the i / iearige ji iccnuponente (^) or the iiohr- uuergiekoniponerite (ii ₊ ).

The food as well as the fjuorescent a ... s ancih i'jr transmitted x-ray ens "rail, .en delivers a; transfer rate correction / • 'tranamiabion correction" / » '» calibrate the effects infox _ri e uer interferences.i. switches off elements, ^ ua -'- itatively goes the) üer ~ ra ^ n- _; .sicorreictür as necessary in front of you: pie iluoressenz-Intensitat of the xcö radiate from the element sought, for example, eide iLvpfer, with increasing concentration of the lion, nij, .... t however uit Z'jnehiaynder concentration of the interference expression, for example . The transmitted intensity decreases with increasing concentration of both copper and iron. iooniit icann da.s ratio of fluorescent intensity to transmitted l

/ "Too much dispersion. Tritium / Zirconium and Tritium Titanium Can used // earth, but at low copper concentrations

9 0 9 8 3 0/1150 BAD OHiGiNAL

(I ₁ ,:. ,,) -> MieiE "-f iiidiiüii against - oer Atiüerunjen eier -konZeutrK ei es liiterierenae. Eiii ^ xibes ^ eiancht, aie iu :: ^r aolis;: enenaen: .j ..kr eri i.utero ndrd.

Jie Tsrv / e-Mdim. ^ Sinögliori-ieitöii the arf indan, s ■ - ,. · ..- 3: c. 'i ^ onnik /: _- ji - irL.-er}:.-... b of the bereiohs of the X-ray ■ "-rrh-: en-jVraoreszsiiz -. ^ .-. 1 / ee - vöi.li, · · General / couoxetel / general /, provided -_ ■ · ■ '"."' ■ samples of kus santer jasse "oro ^ ¹ I xcheiiunit use -; will,

, .- .. sr alternatively that an unabli'n ^ i .e readsimuu ι from ic ^ a

'.j''x'"four m c. about üiiie ^ .u ^ level Ui.sse; ro jj ^1. .-. che ^ unit eri'c. --t. boiiii ι:" i - ü4iii, v ; enn dua above luiirisoe.ie / erf-dliren ver ■■■ vadet we α, das / erli ..tiiis I,. · I, _n so - eiuacht weraen that it was l ^ ai ^ Üüli from the IConze : traaion des ^ esi'oaten J_omei..tes depends, vorat ^; .sgese "; zt that the lasae pro Plaohenei -. ^ isit of the analyzing ... sample has given a pre-.sti ^ below, but for an effective anal ... e zweokia ßi. / UEDE opciuale fund per i \. _ ic Ij s unit is.

TJm the ./irlcunga way of the invention η her zv. er.i ... age, the quantitative effect of the transferring corrective

The target, the final sample is made up of several elements seaen, we o.xo du.ruh d ..3 Symbox büw. Zeioneu "i" d arg es -: il._t be can, /

r. is the concentration of element 1 in the sample,

909830/1150

VSV.ü "vte..i j

jV "ifer) iji air ^ r

■. the j.assenabsorotionoitoefii ^ ienten aer. ~ i

represents E "is the fluorescence energy of the element sought,

/ uj. is the mass absorption coefficient of the elements i at the energy E ^,

E is the energy, the erforder ± I is rah_.e the Roentgen. ^. des ^ es cnten Lienientes z \, excite,

/ υ. aer j..assej.absorption) coefficient of rJ._ renewed i at aer .Mier, ie ^ is,

Lj ^ uii 5ner 'ie der' -LÖnt.ge.u8 '; rü.i- en iß:, .velcha d'.rüh die j / robe tr.i] 8Jj; i "J, iert v / erde., .,

, ",. aer iiassGnabsor-pxiOiis coefficient aer .-:. em." = hte i at aer

^ e L _t ,. ^.,
dii Inte ... sit.α · ;; aer fl 0res.2ieren.den iiöx..tgens \; raiij.en is,

'i.i. Intejxsit; .ot aer sinfaD. ■ end Dtr ^ ki- '· .-- j ..-: "and

. an ivons ^ ante is - .; sj one ν η the geometric j-eisV / ji ^ sf-vliigk-. · 't, the x / etektorleist "η.;. sf ihi ^ keit, the filter e:' - sxuii, jöf higiceit vmd der Hont ysnstro, h ..- en- F ^ -ores .-. enaerre ^ v.ii.aj-eis'ju ^ .- sf ^ hig ^ .bej, the device 'η abhunift ., then .yiit, v / enn dia i-atrixverst: rki'ii _-: seffekte veruachl'iasi · ::!; werueu.!

° ^{1 GU}

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909830/1 150

the j & l. be tr; .Jh: et ouer i -.-. Xeryi-oht v / iru,. <O i ..- L copper ores i ^ .- er / erv / end ^ u; Einsr Aiueriüi id-24-1-quelj-Θ determine i, so.l, ./eraen the values of ± ί ,, λ _ω iuiü, ^h J.

as follows aruienoiiiüiim:

^ = 8.05 keV (for the iu .pf er-Üet -Hö

= 15 keV
. = 60 keV

How later do we incline ao. = L, is'c aie used sample such of aattifster Iviaaae pro j? _Uu.oheneinrieit / "saturation" mass per raiit area / f ^: .r uie; j rahlcn- low energy. The ilbercra-gens intensity I ,,, isu danc-rs

I _rj} = I _o k ₂ exp - Mi (^ V) ₁ (2)

II the tiaase per tfläohenein'neit of the -crobe -.aid k _{2 is} a constant ännlioh of the constant k .., but without the exclusion of Höii'a ^ enstrahxen-excitement _: .s-Le istvingsf ähigkeit.

Therefore:

^θχρ

BAD OFiiGSHAL 90-830 / 1150

IC =

In jj ¹ al --- S aer ivripfer- ^ '. LUoresiseiiZ-Röiit ^ ens ^ rcui e_i is Ei3en a Iiioerf erevizeleuent, we.LOiiea in uer Latrix in, ^ roi Konzentry.tiji.eii (r- _lQ ) be present canoe and so.d ', βϊ.αί.η ι.a;, rix-Absor pt ionsef feiet causes.

^ o imUi, U; ii den i.iaurixei'.elct av.szug-.eiuheü, the xo. ^ end

Conditions-.j erf. ..Χι become:

yi _T > = ο (4)

ie the nairiaiij of Iji / 'lm ao.i.ite iinabh-u: i _; :: ig of aer the iron concentration aein.

, ■ Venn dia- 31eiohun _; ; (3) differentiated and auigslöat is, ru a soj.caen ./ert for the a.iasse pro ίχ ^ οϊιβηβϊχιηοχ. to determine that the differential is gieioh iiull, the op; iuiaj.9 i..asse per yiäohen unit received, Naiülioh

(, -υ f ⁷

It is ersiohtlioh that the foregoing overhead lines do not

909830/1150

_BAv0 o ^ h

- ■ rr i'Jr air ~ f, y ^ neaäcii-i an Anierici- in-2 41- ^ t rah- · on. e. ^ is üv.-tr; - "1'5LL, jüL / isr ^ χ '^ r each" ι ·' ¹ .- .. Il, υ / ο ".J: nu ^ _" .- ^ , ex'oc ieu .-. i siiiuo. ^: - .. ύ- υ ".η-- L. ^ eic.i bind, vi-. ea oei aer θ:" ί.αιαϊ "ι. ^; . ^ - 1Ο9" J "G _: &. Ii .: eiiO ..el e der j'al .: isü, ^ eI ''; ei., aie £ ■ -ic ::. ^1. · = .α osr.i5-.i "ai ^ en, a- ^ ei "d ^: -.ls'■" laifj. u.; are easy, uu souit v / i ..- aj

'"e

j. eiclum;,: (6). ^ - iriii daiui 2 ^ c-JaIa ₁ , as i'oi ^. 'c .oscriijjj weraeni

^L e ^ e

So it is for a given Dtrah-ienauel.e to i'itores- -Hb'iita-e-.s Jrralilenener ^ ie üiög ^ i, a ./erc r.'Ux aie i-ias.se oro jj ^l ja .clieneiiilieit (M. _{Vi) r |} ,) to f inuen the trobe, v / o I_-!, "unabiiclnyig from the concentration of the Interf erenzeiejaentes" 3 ".

jüs has horai'Si - ;; esbel, .t, dab in the weitava j? ^1. , Ien IiQp _T -i- 3? the ber ^ raGiingskorreirU'r _; sroiier a-.s the Satti guij.-3dicice / "s ^ buratiori thickness" / fo.r the fluorescence is. ^ ie "ohjfsika .. isehe thickness of the specimen has a ... a of practically a-Λΰχ iiX'-Diiren erI; in most ϊ'ύ- · .. en beraiis ^ estej. ■ ;. In htaii cliB / x Ji ¹ Jj. ^! en has the V / ei't of "^ prn a .--. rj ^ ieiiu..icn ^ soot or

909830/1150

Icein for a practical PfoDuiiuicke, but this one can by using; a ratio of

_1n Zf.

(I, ") instead of Im / I ™ r-berwunaeii. '^ Rue.!. eim. So I "/ (I,") is used, where η is a positive G-anzzahj. or is a, the i>. eichun ^ (5) in the al., in accordance with inen. Case of:

-1 Ve ⁺ /

u _f )

χ- ^

Sorait is the 1 / ert of Mqpm inn a J ¹ JCtor of η is reduced; for example, if one were to use (Ij ₁ ) v /, the value of L ₁ , - ha. o becomes as large as it would otherwise have been. , / if the value of η zi is still, werue.i ge dt oh jj'elu er in the measurement of I _m (soft Gewöiuu.ich ii.i Beζ. ■ =. .f diejenigeii in I ,, zu vernaohj ^: issi; ren are) ... great.

It should be noted that for a, -e .-, plane \ / ert of Mq ^ ,,,, an exact equalization will be achieved with aer i-'robejaz ... suiiiiuensatzung, for which M _O pm esp "iiuui; has been, but in practice it has been found that the ^,. so-called eich over a wide Z-Jsa.tuei.se! Le Lasse pro Ji ¹ J ^ .cheneiriheii ;, (L. _JM ), u <... ngt j.-dojh not only from the sample consistency: jaenser, z- ^ k, but a ·. On doing the kind of Strahxencuei.ej z. ^ .. is at an Amerioii ^ n-241-o; rah ^ enquelie M _Q p _T 6.25

g / ciii, w hifend i "I: ·? a Jadmii iü-1 oQ- ^ trah .encuelxe M, .pm 0> 43 g / om ⁴ " is.

BATH ORIGINAL 909830/1150

The . transfer; 3korr9k ^; : i.ir-l'eo] i £ iiK Can also use > z ./erden, if a £ το .. ·, ϋ number from I_i: erferenze. ..menten is pre-Iiariden. . For every IL / saferenzeleüienc a, υ, ο ... is the u ·. eiotiung for M _O p "auciers, da

^(7a)

i ^s <.% " ^{! u} f ^} i ^r J ¹ i ¹ - ^ X ^ ^(7b)

¹ &quot; VV ^ e

909830/1 150

⁷ ORIGINAL BATHROOM

-H-

However, since E and ~ <i "are fixed and so chosen are sin-a, aa 'they

θ X

in the pnotoelectnuchen jiereic ^ lie, (sit; ne j and O)) "are the ratios (/ ^u f // ^u _e ) ^{i; ir} j ^ -des of the interference elements a, b, c ... die, lcior.en , ana t, ov / i .cd the value of M _{ü? fJ} , _{for which} elements the same sej.ii. The exception or deviation from this occurs when the interference element has an absorption edge between E ~ and ü. In this exceptional case, however, the Interele.iiei: tL "ifx" ect will be small, and few elements will fall into this category, the transfer correction technique is particularly advantageous if a large number of interference elements are present in the sample.

One form of application of the invention will now be explained in more detail with reference to the drawing reproducing it, for example, and that is reluctant

Pig. 1 is a schematic representation of the used Contraption,

3? Ig. 2 an ID curve in which the fluorescence intensity of copper K. X-rays - (X ₃ ) plotted against the copper concentration (r) under the presence of varying concentrations (rg,) of the interference element iron when using an americium 241 oil source is,

Fig. 3 is a curve in which the ratio

909830/1150

BATH ORIGINAL

against the copper concentration in the presence of ver ^s .nderlic: ien concentrations of

when using an Amerioium-241 Ötrali is worn away;

4 corresponds to J? Ifj. 2 using ej.ner cadmium-1 u9-t> tra] ilenquelie,

wälix'end

5 Fig. 3 using a cadmium 109

is equivalent to.

iäi Pig. 1 there is an X-ray source, ' the one Am-5riciuia-241 radiation source i-b, under a sample 2 to be analyzed. Sample 2 becomes the optimal one kasse oro iläcLeneinlieit have, v / ie you from the (xleiclmng

(5) is calculated if a matrix of OuO / Ji'e O./öiöp is assumed. The optimal mass per unit area can be calculated using known values of / u »/ U ^ and / U, for iron and unity. The value for 5 ( ax _& + / ^u f) -i ^r i> ^which corresponds to a sample containing 2.5 ^ copper and 2.5 '/> bis, can be calculated, with the result M _O pm = 6 , 25 g / cm ^ is.

o'rj ^ r of the sample 2 is a lead collimator 3 via \ isichern a road ^ lendetektor 4 is provided. A filter 5 is provided between the Iolli.-iator 3 and the detector, o, the purpose of which is to filter out low-energy and fluorescent X-rays from the transmitted radiation, ana v / tlcher zwec :: ioäöig an iron filter of the thickness of j, 2b mn can be. The collimator 3 produces a narrow

909830/1150 IAD original

len beam of transmitted radiation, which on the Detector 4 is noticeable, which can be of "any suitable type - a scintillation counter is in the Diagram shown - and which the intensity (ij the measures transmitted radiation.

A second radiation detector 6 is under the radiation source 1 and the sample 2 arranged, this detector measuring the intensity (1 ™) of the backscattered fluorescent X-rays measures. The detector 6, like the detector 4, can be of any suitable type is shown here as a proportional counter.

One of two differential filters 7 is arranged between the radiation source 1 and the detector 6. The filters 7 are used in series, one of which is effectively transparent to the oharac-teristic copper X-rays, while the other filter is effectively opaque. When copper is the energy of the fluorescent X-rays 8.05 keV, and the filters are selected such that a K-absorption edge among d, 05 keV, has as manganese 6,542 keV,> Jisen 7,113 keV or cobalt 7,713 keV, and the other has a K absorption edge of approximately 8.05 keV, e.g. nickel 8.337 keV, copper 3.932 keV or zinc 9.662 keV. The preferred materials for the twin filters are Kabalt and nickel, ie those with an absorption edge that comes closest to 3.05 keV.

909830/1150 bad or, g, nal

While it is absolutely necessary that the absorption characteristics of the two filters are very different in the energies range from 7.713 to 0.37 keV (i.e. between the respective absorption edges of the two filters), it is just as important that outside this range the absorption characteristics of the both filters are adjusted so that they are more or less the same. This can be achieved in that in the sample position / elements are used which give X-rays of energies that fall outside the energy range that comes between the absorption edges of the two filters. The thickness of the filter is then adjusted, for example by filing, etching or polishing, until the counting rate f ^for each filter is the same for a specific X-ray beam.

To prevent direct radiation from entering the Detector 6 enters or penetrates, the radiation source 1 is in a radiation source holder 8 made of suitable material, for example gold, and of a thickness which prevents radiation into the detector 6 directly from the supply source 1 enters, held.

. In operation, the device is constructed as shown, the filter 7 being the one which has an absorption edge below 8.05 keV, e.g. cobalt. The amount of radiation those on each of the detectors 4 and 6 in a given

909830/1150

If the time period falls, it is noti'.rt, and the S ¹ Hter 7 is then changed to the one that has an absorption edge of over 0.05 keV, aB wrap. The amount of radiation that falls on detectors 4 and 6 in the same period of time is again u.otja? T. The intensity (Im) of the radiation incident on the detector 4 will be the same in both cases, while in the case of the detector 6 the intensity (I-cm) of the radiation - using the ijic'rel filter, will be greater than the intensity ( Ipo) using the cobalt filter.

5fj BATH ORIGINAL

& 909830/1150

The intensity (I-,) of the fluorescent X-ray

shine is:
¹ F.

If I ~ and I ^ are known, the ratio Lp / Ιφ can be easily calculated, and the concentrations of copper in the sample can be easily determined from a calibration curve such as that shown in Fig. 3.

In FIG. 2, calibration curves are shown which, using an americium-241 radiation source, show 1 ^, plotted against r, where copper is the element sought. The copper concentration is in the range from 0 to 5 ° with an iron content that also varies in the range from 0 to 5 %. In normal analysis, the iron content will not be known, and the inter-element effect between the iron and the fluorescent rays of copper causes up to $ 1.5 uncertainty in copper content. For example, if I-, has a value such that

TT-4- x 100 = 1

then the copper concentration can be anywhere between 1.95 lh and 2.8 i> , depending on the concentration of the interfering iron. When the concentration of copper is closer to 5 #, the uncertainty becomes even greater.

909830/1150

If the method according to the invention is used, I- and I ™ are measured and the ratio 1 ^ / 1 ™ is plotted against the copper concentration, a result as shown in FIG. 3 is obtained when an americium-241 radiation source is used . From this curve the copper content can be measured to be about 0.02 <$> , even though the iron content is completely unknown in the range of 0 to 5 % .

The technique of using a cadmium 109 radiation source is the same as for the americium-241 radiation source, with the difference that the sample thickness in this one

ρ
Case is 0.43 g / cm and the filter 5 is not required. The results obtained with a cadmium 109 radiation source are shown in FIGS. 4 and 5, from which the effect of the "transmission correction" can be seen.

It can be seen that in practice it is necessary to test the device prior to use to verify that samples of known composition and of the same mass per unit area are used. It is desirable but not required that the Apparatus is calibrated and used at a sample mass which is the optimum as calculated from equation (5). However, it is necessary that the device is calibrated and used at a constant sample mass since the Calibration is only correct if the sample mass is constant and inaccuracies are introduced by changing the sample mass.

BATH ORIGINAL 909830/1150

Although the invention has been described with reference to a sample containing copper in the range of O- 50 and iron in the same range, it will be appreciated that the technique can be extended to other concentrations of copper, iron, or both, as well to other elements such as zinc in a matrix of zinc sulphide, lead sulphide, iron sulphide, silica and calcium carbonate, with nickel and copper being used as differential filters.

Although the inventive method based on Has been described ores, it can be seen that the method according to the invention also applies to other materials could be used, such as a solution, a slurry / or a powdered solid.

For a sludge, for a material of "saturation thickness", where E = E ₊ , equations (1) and (2) are modified so that:

L ViWs ^ _ ... (1O)

l1 - T _a ) + r _B. * [( / i)

_t ■ / U r + / u (1 -

T - lc T 6yt> - 7 χ / SS / W ^v

¹ T - Vo ^e * P ^ίχ · ι _ _{rs (} i _

r_ the fraction by weight of pesticides in

the mud
r is the fraction by weight of copper in the solids,

909830/1150

r. is the weight fraction of element i in the solids,

P _{3 is} the specific weight of the solids, χ the sample thickness,
/ U ₃ = -C / Ug.r). is and
the suffix "w" refers to water.

When the invention is applied to a slurry or a solution, a flow cell / flowcell / used for the "transfer correction" measurements. In such a case the sample thickness χ would be constant, but the density could either be as a result of changes in the composition of the solid or as a result of Changes in the solids content of the sludge vary. The density would have to be determined separately and this can be done using a gamma ray densimeter or other suitable densimeter.

If a powdered solid is used, the procedure is similar to that where an ore sample is used wherein the pulverized solid is presented in a constant mass per unit area.

The invention also relates to modifications of the im attached claim 1 outlined embodiment and relates above all to all features of the invention, which individually - or in combination - are disclosed throughout the specification and drawings.

Claims. 909830/1150

Claims (22)

1. Fluorescence X-ray analysis method for the! estixuiiiurig the aonzeutration of a sought element in a material, characterized in that X-ray len into a sample of what you are looking for entiia.lt end en Ka- terials conducted ν / ε-rden, the fluorescent X-rays of the searched 'JIe me nt it. ax x-ray iso-Ii. rt, which are backscattered by the sample, the intensity (ij,) of these fluorescent X-rays and the intensity (I ₁ J of X-rays that are passed through the material, are measured and from an Alich curve which The ratio of I- _n to In ₁ or a multiplicative coinage of I_ or L ·, plotted against the concentration of the element sought, gives the concentration of the element sought practically free without inter-element effects. 2 , method according to claim 1, characterized in, 909830/1150 BATH ORIGINAL - '4T- that the fluorescent X-rays of the element sought is thereby isolated from the backscattered X-rays such backscattered x-rays will alternately pass through one of a pair of differential filters for equal periods of time, with one of these Filteijpermpermert for the fluorescent X-rays of the element sought and the other effectively (light) opaque. 3. The method according to claim 1 or 2, characterized in that the sample of the material to be analyzed "Saturation Density" for excited X-ray fluorescence 4. The method according to any one of claims 1 to 3 »characterized in that the material for the analysis as solid sample of known mass per unit area is presented. 5. The method according to any one of claims 1 to 3, characterized in that the material as a sludge of known thickness and density of the analysis is presented. 6. The method according to claim 5, characterized in that the density of the silt is determined independently with the aid of a gamma ray Dichtö & esser. 909830/1150 7. "The method according to claim 1 to 6, characterized in that that the x-rays directed into the sample are essentially monochromatic. ö. The method according to any one of claims 1 to 6, characterized indicated that the X-rays guided into the sample a high energy component and a low energy component exhibit. 9. The method according to claim 8, characterized in that ^: 3 v / ground the fluorescent x-rays with low energy from the transmitted x-rays with the aid of a filter. 10. The method according to claim 8, characterized in that daid a narrow beam of transmitted radiation durcii Koilimatormittel is generated. 11. Apparatus for fluorescence X-ray analysis, characterized in that it has a radiation source, a detector for backscattered X-rays and means for holding the sample to be analyzed. 12. The device according to claim 11, characterized in that that it also includes a collimator for generating a narrow beam of transmitted x-rays. 909830/1150 -Jr- 13. Yorrio. ".Tan £ nacl · .. .ans pr lic'ι. 11 oo.-r lc, a. \ A \: x: oL · gekemnz, -: lo. R ·. / J, Gy, :; a: .Q i'ixttei to choose whether fluorescence X-ray beam energies have a pair of differentialiilt-r. 14. Device naoh .ans ^ i'uch 13 »characterized in that that the sample to be analyzed is an i; upj: obtained Material is. 15. Device according to Ansoruch I4, characterized in that because the differential fil was made up of cobalt and nickel are. 1b. Device according to claim 13 »characterized by: '.: e.': Ermzeicnnet, The sample to be analyzed is a zinc-containing material is. 17. The device according to claim 1o, characterized in that because: 3 are the differential filters from liickel and liupfor. 18. Device according to one of claims 11 to Vi ₁ characterized in that the radiation source is the cadioisotope Cadmiuin-109. 19. Device according to one of Ansor'.ch.e 11 to 17, characterized in that the radiation source is a radioisotope selected to be components 909830/1150 _BAD ORIGINAL of »radiation with lower and radiation with contains high energy. 20. The device according to claim 191, characterized in that that the radioid stop is Americiuin-241. 21. Apparatus according to claim 19 or 20, characterized in that a filter is provided to the filter out low energy fluorescent x-rays from the transmitted x-rays. 22. The apparatus according to claim 21, characterized in that when the sample contains copper, the filter for the transmitted x-rays jüisen with a thickness of 0.25 mm. BATH ORIGINAL 909830/1150 -it * Blank page