US2329320A

US2329320A - X-ray tube

Info

Publication number: US2329320A
Application number: US440516A
Authority: US
Inventors: Zed J Atlee
Original assignee: General Electric X Ray Corp
Current assignee: General Electric X Ray Corp
Priority date: 1942-04-25
Filing date: 1942-04-25
Publication date: 1943-09-14
Anticipated expiration: 1960-09-14
Also published as: FR942221A; BE475842A

Description

Sept. 14, 1943. z. J. ATLEE x-BAY TUBE y Filed Apil 25, 1942 Ill lll lltill- IN V EN TOR.

uw w

y l BY: Zedfafz, um

J dendsltea onf' erator...

Pfented Sept. `14, 1794.3.y y y .invention v.relates fnrgvgnenalftp eleeglouljnwcsk and has .more particulr {eferene ftp :an Xrray generator having lam anodeproviding 211, electron.

application .pff

Spnlyjomrg@ aline @rid then:

^ t ame 50 ateria'llin theispestmgraph of the 'materialbeinggexammed materials by `)bray diffraction, I have ,providedl y an'X-ray generator having means incorporated therein for changing, at will, the target material 'carried by `the anode Afor 'receiving electron ini- K' pingement in the generation of X-rays at the target; `and to illustratethe invention, IV, have shown on the'drawing anvX-ray tube I compris-` ing ananode I3 and a. cathode I5 ein facing relationship'` and enclosed", within Van jhermetically Vsealed and evacuated envelope I1 and having suitable electrical connections vextending through g the envelope for supplying the anode and cath- I ode with electrical power from a suitable external source. Thecatho'de I5 maycomprisevan ,elec-l tron emitting filament 25 mountedl on a ,head I9 which in turn is'supported and sealed upon a re-,entrant' envelope `portion.comprising afhfollow,

stern 2|. 'The filamentitsell may be supported through the openings `in the cathode skirt, 'the windows 41 and thesleeve openingslf The anode I3 comprises a base of suitable material, such as copper, forsllpporting an elec tron target thereon atl the target end 3| of the anode. I may employ any suitable-target matefA rial, such as chromium,V cobalt, ni::kel,-liron,k copper.manga.nese, vanadium, f nmlybdenum,y

tungstenor titanium. i' vThe anode I3l preferably Within the envelope of thegenerator` for applying Atargetmaterial tov-the target surface 3| of the 4anode,said `means ,being controllable from outside of the envelope; andthe invention contemplates means operablev to apply'any selected` one rof a d number oi" diiferentjtarget `materials upon ,the

at its opposite ends on stems, including rstemY at one 'end of the filament extending through a duct in the head IS and supported in suitable'clamp means behind'the head -wher'eb'y *to-f space and insulate the steinl fromthe'head. fAtthe other"v .f end ofthe iilament, the supportstem4 may vpass,

througha similar duct, :orthevstem ymay be'p'ress- `iitted ina socket inthe head whereby to 'electri-y cally connect the filament on theA head. Conductors 23` for energizingtljle electron emitting lament 25 are'sealed in Aand may extend through the stem 2| and outwardlyvof the envelopeatfone end of the generator.for'connectionr with a suitable externalsource of povverfor energizingfrthe for depositing the target' filament for electronl emission. LAs shown, 'chef n conductor 23 is connectedvvithmone vof the la- `ment stems whilethe,kothercconductor is con- K nect'edtothehead.

i It win benoted therme' filament ris. oreiongad character and is supported ina groove 21 formed in the cathode head whereby electrons emitted byf ythe `filament, VVWhen; energized," will be` focusedY uponthe facing ox" `targetfend. y3| ofL 'the anode.' The anode, near' its target remote end; is formed with'ashoulderitogwhichis sealedai rdiskV or washer 33having` 'anannularredgei forming a glass-tomctal seal`35 Withare-entrant envelope portion 14|","' the anode* having4 an rextension 43 rod of target material `51?'15 `ermmiediwir supportedby a preferablyhelically dispose projecting Vou'tvvardly.of theenvelope y'I'lhrfough the' conduits Y45 for the' circulation ofja ,cooling iluid into 'the anode and ,adjacentil the l target thereof forco'olingth'e anodef f washer 33lanclbeingtted,Witlr'finlet'andoutlet connectedl with4 jthefflieating*i'llanfierit IBilthrough .Y `its support nstems; the conductors` extending thence outwardly" of Athe yenvelopethrough'fthe hollow re-.entrant ste'mlZ I Aand Zthrough suitable to X-rays, the Windows K l41 being fpreferably.

locatedonthe envelope opposite the target end i of theanode inposition to project'XV-rays ema;-`

nating v,from the target end'of the" anode outwardly of .the envelope`- The cathode vheadvalso isfpreffv i erably provided withc'a skirt 3.49 iencircling. the Atarget'end of the anzode'and formed Withv openings 5 I jiori the transmission, of useful l Xeray, beams from the l, anode ,'to and through l*the windows 41,;

= Ihetubealso is'preierably enclosedinfanannular s ,Sleve 53#whiamwwmprise.split Yparissili: ably 'Clampedffigiher around Window por-1 tion- `of` theenvelope, thefsle'eve,` 53 being provided with `openings. 55;fcr receivingl the. windowfcazrryf ing envelopeprojections. If dasired,"the1sleeve 53 `may be formed. of material opaquetofX-rays :for

.the purpose `of' confining. therein all'k X-rays except the :beams which emanate'frorn thev anode d t6 cover adeiinitey area of the target',"suriya y -Iby shaping the'notch orvslo'tg` 69; substantially? plc'- i "s and opening on Saidflld'n. direction fa cinThg4 `target surface, said Amaterials being applicable.

successively and atr anytime, throughout ,the

' service' life of the generator-,j whereby the characterl 'of the anode target, Aand"jconfseouer itly the {.eslcfthe seawater- X-ray spectralcharacteris may rbe' 'changedl` atfvvill.;

., To this fend,LIyprovide"Within:l

toward the targetfsurfacem of lietaiiod ing niament 6l wincvhfwitnftnerodi- 51;

posed lwithin thec'avity 59;V *i

i cludmg erstem at Oheen'd" Q ihelmenfex ,'tendingfthrough-'a ductinthe head 'IB-a dj'supf ported in l suitable cljamp`means1behindthefheag a tpe-stemrromtne" fllament'; the sup-V l Whereby'to spaceand111511119X?.Vj

port steinE `inavd pass4 through the head whereby to electrically crmect ther ima! v may Abe Separate orwhicii may? thefhadl 'con-` nected yfilament conductor 23,are dielectrically the conductors 23? lByf'cofnrle' ating theheating lament conductors with? 'l v. electricalpower `oi'itW-ai'dlyfi l ffth of -the rod 51.); The'.vaporized'fmateal'soi-generated in the' cavity 59.6will be expelledjherehjorn.

as indicated in' dotted lines in Flgilreythrolighf the loprenisaf; the cavity .5S-.and bus-'dlr te upon.r4 the targetg.surface 3| fof the. a a will condense l threonandadh 'thertd cordance with the Vconiiguration'of Ath'e-"fl'zx'ia""ci.

first-finished to a desired size and shape andris then` assembledL.` andsealed inftheenvelope, g-Meansis provided *suitable source" -1 of Y Y ",r1velnSe-.-y AVthrough suitabler current fcontrolldevicesthznlal 1 ment 6| may be heatedvg'to any; desired; temper.-v

ature necessary to lvaporize': the LA target 'material Y the target surface to vbe coated with target material. In this connection, where the electron emitting filament 25 of the cathode comprises an elongated element, as shown in Figure 3` of the drawing, electrons emitted bysaid filament will impinge uponfthe target surface 3| withinV length as the elongated cavity which contains the cathode filament 25, and by making the rod of target material 51 substantially the same length as the filament 25.

The film of target material should be applied to the anode while the latter is at a temperature causing the vaporized target material readily to condense and adhere upon the target surface of the anode. The temperature ofv the anode, however, should not be high enough to promote solution of the vaporized material with the material of the anode base to any degree more than necessary to allow the target material to wet and adhere on the anode base, as otherwise the target material in the film 65 may become contaminated by the material of the base should alloying occur to any extent throughout the thickness of the film. For this reason, it is desirable that the anode base be held at a temperature but slightly higher than normal room temperature while the film 65 is being applied. The film 65, of course, may be applied by depositing superposed layers of material on the anode base.

In order to facilitate the assembly of the rod 51 and filament 6| in the slot 59 which, it will be noted, is inclined in the head I9 to face the medial portions of the target surface 3l, the head may be formed with a demountable segfrom the foregoing description, and it is obvious that numerous changes may be made in the form, construction and arrangement of the several parts Without departing from the spirit or scope of the invention, or sacricingany of its attendant advantages, the form herein disclosed being 'ay preferred embodiment for` trating the invention. f

The invention is hereby claimed as follows:

l. An X-ray generator comprising a sealed envelope, an electron emitting cathode and a co-operating anode baseforming a target surface insaid envelope facingsaid cathode, said 'cathode having a head provided with a cavity in spaced relation with theelectron emitting portion of the cathode, a supply of target ma.- terial in saidcavity, heating means for vaporthev purpose of illusf izing said target material, means for energizing the heating means from a controllable source ment 61 which, when in place, defines one side of the cavity 59. By removing the segment 61, the filament and rod -51 may be easily assembled in position on the head I9. After the filament and rod are thus assembled on the head I9, the segment 61 may be replaced and secured on the head by suitable preferably threaded fastening members.

It is thought that the invention and its numerous attendant advantages will be fully understood wherein the cavity is provided with an opening toward the medial portions of said target surface and said supply of target material and the means `for vaporizing the same are supported in said cavity. v

6. An X-ray generator as set forth in claim l, wherein thecathode head has ademountable section deiininga sideof the cavity whereby to facilitate the assembly of the target material and the means for vaporizing the same in said cavity.

7. An X-ray generator as set forth in claim 1, wherein a plurality of unlike target materials are supported within the envelope so that a selected target material may be applied to said target surface at will during the service life o-f the generator.

ZED J. ATLEE.