US2373661A

US2373661A - Electron discharge vessel

Info

Publication number: US2373661A
Application number: US518379A
Authority: US
Inventors: Phillips Henry Alfred De
Original assignee: Individual
Current assignee: Individual
Priority date: 1944-01-15
Filing date: 1944-01-15
Publication date: 1945-04-17
Anticipated expiration: 1962-04-17
Also published as: GB592015A; FR911147A; BE459389A

Description

H'. A. DE PHILLIPS ELECTRON DISCHARGE VESSEL April 17, 1945.

Filed Jan. 15, 1944 2 Sheets-Sheet l we w,

April 7, 45- H. A. DE PHILLIPS ELECTRON DISCHARGE VESSEL Filed Jan. 15, 1944 2 Sheets-Sheet 2 INVEN TOR HEN/FY A. flE/ H/LL/P6 Patented A r. 17, 1945 STATE-s ELEotrnoN DISCHARGE VESSEL Henry Alfred DePhi llips, Belleville, N. Application January 15, 1944, Serial No. 518,379

' 20' Claims. (01. 250-154) a v My present invention relates to electron discharge vessels and more particularly to discharge vessels for emitting electrons into the space outside of these vessels.

It is an object of my, present invention to provide an electron discharge .vessel .withan electron transmittingwind'ow of an entirely new type per mitting' passage of a relatively large percentage of'th'e electrons; created by the cathodein this vessel into the space outside of the same.

'It is a.further object of my present invention to providega new type of electron transmitting windows for-electron discharge vessels which are simple in construction and reliable in operation.

Itis still a further object of my presentinve'ntion to combine electron transmitting windows.

with an accelerating electrode of entirely-new type in such a manner that this accelerating-electrode serves for supporting and reinforcing the fragile sheet of which this window consists.

It is another object of my present invention to provide anew electron tube emitting electrons through an electron transmitting window which needs a much lower voltage and has much larger electron output than otherknown electron tubes of similar type. r i

It is still another object of my present invention to provide anewtype of'accelerating electrorle which is arranged inside of the electron discharge vessel, e. g;,'electron tube, avoiding the danger of electrical shocks created by accelerating electrodes of customary type which up to now were usually arranged outside of the discharge vessel'ortube.

With the above objects in view, my present invvention relates to. an electron discharge vessel.

' the discharge vesseladjacent to the above mentioned'thin wall'portion, covering the same.

This accelerating electrodemight of course be shaped in the most different ways; One of the preferred embodiments of such an accelerating electrode is a very thin accelerating electrode plate provided with a great number of small ap erturesserving'for the passage of electrons. An other embodiment of such an accelerating electrode consists-era flat accelerating electrode grid forming. a'plurality of grid apertures through which the electrons accelerated by the-'gridare passing. i

I have found'that the thin electron transmitting wan portionin' the wall of the discharge vessel, e. g., in the wall of the electron or cathode ray tube, is extremely fragile since itis subjected to considerable stress by'the vacuum inside the discharge vessel or cathode ray tube. Ofcourse, the electron bo'rnbardme'nt to which this thin wall portion is subjected during use also deteriorates the material of which this thinwall portion consists and causes b-reaking of the; same after a rel- 1 5 atively'short periodofuse."

- I have found that this thin wall portion 'of the discharge ,vessel can be substantially reinforced by sealingthe above-mentionedaccelerating electrode to it, i. e., combining this wall portion with this accelerating electrode in such a manner that they'form practically a single unit; Of course, it

is practically also" possible to embed the-accelerating electrode-'particularly if ithas" the shape of a gridat least partly into thethin wall portion, thereby forming a composite sheet servin simultaneously as wall and electrode. Such a combined" electrode-and wall might be subjected to much greater stresses than not reinforced electron transmitting wall portions, so-called Lenard windows'of usualtype;

In order to enable sealing of the electrode to the electrontransmitting' wall portion, both'these parts haveto be made'ofmaterials having at least substantially the same temperature co-efiicient, i. e;, thematerials ofwhich the electrode "and wall portion consisthaveto expand in the same way and degree-whensubject ed to equaltemperature variations.

' Since the-thin walltportion forming part'of the i 0 electron transmittingtwindow consists preferably of an electricallyv non-conductive material, I make it of glass. The electrode has to be electrically conductive and therefore I use an electrically well-conductive materialior making it, such as a metal or an alloy. In a preferredv embodiment of my new tube, ,1 make the thin wall portionof lead glass and use an alloy comprising nickel, iron, chromium, andtraces of cobalt for the ac,- celerating'electrodeflsealed to the same. I have found that this alloy has at least substantially the, same temperature co-efiicient as lead glass. Thus, if such an allcy'is sealed to'lead glass and exposed to temperature variations within certain limits, it will expand in thesame way as the glass and'thusnot become detached from the same.

The novel features which I consider as characteristic for my invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings, in which:

Fig. 1 is a longitudinal section through a part of an electron discharge tube having an electron transmitting window comprisinga thin wall por tion and an accelerating electrode sealed thereto in accordance with my present invention;

Fig. 2 is an end view of the accelerating electrode shown in Fig. 1, seen in direction of arrow 2 on Fig. 1;

Fig. 3 is an end view of a grid-shaped enibodb ment of my new accelerating electrode;

Fig. 4 is a side View of an entire electron emitting vacuum tube, partly in section, provided with a modified electronv transmitting window according to my present invention; and

Fig. 5 is a side view of still another modification of my new electron transmitting window particularly adapted for irradiating substances passing through an irradiating tube arranged within the discharge vessel.

As shown in Figs. 1 and 4, the evacuated electron tube 10 used for the purposes of my present invention contains electron emitting means II and a first accelerating electrode I2. Both these electron emitting means I I and accelerating electrode l2 are of usual type, well-known to everybody skilled in this art, and therefore need not be described in detail. The metallic coating l3 on the inner wall of the evacuated electron tube In serves as second accelerating electrode and is connected with an electric circuit in well-known way by means of an electric contact I4 and an electric conductor, not shown in the drawings.

As mentioned above, I provide in wall lb of the electron tube I an extremely thin wall portion [6 made of an electron transmitting electrically non-conductive material, e. g., glass. This wall portion II; has preferably a thickness of less than one thousandth of an inch and is sealed into a corresponding opening in the wall ii for instance in the way shown in Fig. 1.

It, has been found that a Window of such extreme thinness is preferably produced by separately making a glass foil thin enough for the.

purposes of the present invention. Such a thin glass foil can be made by blowing a glass bulb having a wall of the required thinness and then sealing a portion of this bulb wall into the open end of wall l of the electron tube ID. This sealing process is preferably executed by heating circular edge I! of the opening in wall 15 and then contacting the glass tube blown in the above described way with this heated edge portion of wall 15. This contact causes the extremely thin wall of the glass tube to melt along the contacting edge and to adhere permanently to the same, thereby covering the opening at the end of the tubular wall IS with the needed eX- tremely thin wall portion I5.

Adjacent to this'extremely thin wall portion I6 I arrange the thin plate-shaped accelerating electrode l8 shown in Fig. 2. This accelerating electrode is provided with small apertures l 9 enabling passage of the electrons 20 emitted by the electron emitting means H and concentrated on the accelerating electrode [8 by means of the electrodes 12 and I3.

As shown in Fig. 1, this accelerating electrode 3 is sealed to the extremely thin glass wall portion It supporting andreinforcing the same as well as to the adjacent wall portion 2| of the tubular wall 45 of electron tube It. This accelerating electrode I8 is connected with the corresponding contact member 23 by the conductor 22 in the usual manner. This contact 23 is then connected with an electric circuit supplying the accelerating current for the accelerating electrode I8.

I wish to mention that I might produce an electron transmitting window of the above described type also by first inserting into the opening at the end of the tubular wall 15 the accelcrating electrode I 8, heating the same and there aftercontacting a thin glass foil of the type described above with the outer surface of the thus arranged heated electrode 13, thus causing this glass foil to melt and to adhereto the electrode l8 and the edge I! of the tubular wall l5. In this case, part of the molten glass will enter the apertures i9, thus forming a single composite unit consisting of the electrode 18 and the glass foil it partly penetrating into and filling the apertures IS in the electrode and firmly adhering to the same.

As mentioned above, I might use also a gridshaped electrode 24 of the type shown in Fig. 3 instead of the plate-shaped electrode 18 for the purposes of my present invention. Such a gridshaped electrode is then arranged in the same way as the plate-shaped electrode shown in Fig. 1 and thus need not be described in detail. I wish only to mention that it is important that the wires or narrow straps 25 of which this grid 24 consists are connected with each other at their intersection points in such a manner as to form one single electrically conductive unit. Of course, such a grid-shaped accelerating electrode will also concentrate the electrons 20 so as to force them through the grid apertures 25 against and through the thin glass wall l6 behind the grid. In case such a grid is used as accelerating electrode, it might be made of extremely thin wire and practically embedded into the thin glass wall 16, thus forming a combined wire reinforced glass wall portion serving as accelerating electrode.

In Fig. 4 another embodiment of an electron tube with an electron transmitting window of the new type proposed by me is shown. In this tube, the electroneinitting means are provided in the usual way. However, the electron transmitting window 2'! is not arranged in the wall l5 of the tube but I provide an additional glass tube 28 sealed into a corresponding opening 29 of the tubular wall 15 as shown at the top of Fig. 4. The bottom part of this tube 28 consists of an extremely thin wall portion 36. The cupshaped accelerating electrode 3! is placed over the bottom portion of the tube 28 entirely enclosing the same and sealed to the wall of this tube 28 as well as to the thin wall portion 30 at the bottom of the same in the way described above. Of course, this electrode 3| is also provided with small apertures 32 of the type described above and thus operates in the same way as the electrode shown in Figs. 2 and 3. This embodiment of my present invention enables placing of substance, e. g., fluid, into tube 28 and irradiation of the same by electrons while the irradiated substance is arranged in direct contact with the elect'ron transmitting wall portion 30 The embodiment shown I in 5' is par-ticw larly adapted for irradiatlng 'fluid's during passage of thefsamethrough an irradiating tube M a-r rangedf. within- 'electron- 'tube For: this: pur

pose, this irradiating. tube 32 -isconnected with an inlet' tube 33 'and anoutlet tube=3Land-all three tubes 'jare isealed into the wall- I5: of the electron tube W in the way shown in Fig; 55..

In: the wallof the irradiating tube 32, .I provide an: extremely thin glass 2 wall portion 35 oflthe type described above. This glass waillportionifil:

and the adjacent-portions of the outer surface I of"-irradiating*tube 32 are covered. by a; semitron-transmittingelectricallynon-conductivematerial, and a flat accelerating electrode grid-forming: a ..p1uralitys of grid apertures for the passage of:electronsbeingiarranged: adj acent to that surfacezoflsaidzthin' wall 'portion' w'hich is inside said I electron' discharge vessel covering said?v surface and :thus' supporting sai'd'rthin 'wallipo'rtion of said cylindrical acceleratingelectrode 35 of thetype described} Of-course, this: accelerating electrode 1 35 is =seaied-to1the'thin: glas's wall portion 35:3116' to the adjaxient wall portions of irradiating tube 32? in the way explained and descrihed" above." By

means of conductor 31 this accelerating electrode aesconnect-ed to-contact 38 which in turn is" connected to: an electric circuit supplying the needed acceleratingcurrent by a conductor: not:

showninthe drawings;

It=will he understood that" each .of:' the elements spiritof'my-invention.

Without further analysis, the foregoing; will so fully reveal the 1 gist-of" my invention that. others canby applying: current'knowledge read? ilyadapt it" for various applications without electron dischargeevessel.

In an: electron discharges vessel discharge vessel, said electron transmittingwinzd'ow'comprisinga thin walltportioniof an electron transmitting: electrically non-conductive material.

and azflat accelerating electrode. providedwith a plurality of: apertures for the; passage of electrons beingrarranged adjacent to that surface-oi" said" thin wall..portion-.whi'ch is inside of said.

electrona'discharge vessel, saidxflat accelerating electrode beingsealdto-said thin wall portion forming one single; unit with: the same and thus supporting said. thinwallportion of saidselectron dischargesvessel. I

5'.--Inan-ele'ctron discharge vessel for emitting.- electrons into the space outside said. vessel an electron-transmitting. windowin the wall of said discharge vessel, said;electrontransmitting window- -comprisinga thin wall portion :of an electron transmitting electrically non-conductive. mate rial, and a thin accelerating electrode plate provided with a plurality'of' apertures for the passageof.electronsbeing arranged adjacent to that surfaceof said thin wall-portion which is'inside said; electron discharge'vesseLi said: thin accelomitting features that, from the standpoint of prior"'art, fairly constitute essential characteristics of the generic or specific aspects of thisin' vention and,"therefore, such adaptations should and are intended to be comprehendedwithinthe meaningand range of 'equivalence of the following claimsi 1 g i What I" claim as new and.desire-to= secure'by Lett'ersPatntiSz' 1. In'an electron discharge vesselforemitting: electrons into the space outside said vessel an electrontransmittingwindow in the wall of said:

discharge" vessel, said electron transmitting win;- dow comprising a thin wall portion of an electron transmitting electrically non-conductive material, and a fiat accelerating electrode'provided with a "plurality of apertures: for: the pas:

sage of electronsbeing arrangedadjacent tothat" surface of 'said' thin wall portion. which: is inside said electron discharge. vessel covering said surface and thus supporting said thin 'wallportion of saidfelectron discharge vessel.

2. In an electrondischarge vessel for emitting electrons into the-space outside saidvesselanelectron 1 transmittingxwin'dow in the" wall of said discharge vessel, said electron transmittingwim doW cOmprising a thin wall portion of an ele.ctron transmitting "electrically: non-conductive material, and a thin passage'of'electrons being arranged adjacent to that surfaceof said thin wall portion which. is

inside said electron discharge vessel covering said surface and thus supporting said thin wall portion of I said electron discharge vessel.

acceleratingelectrodeplate provided'with a plurality of aperturesfor the eratingelectrodeplate beingsealed to said-thin wall'portion forming one single unit with the. same rand thus supporting-said, thin wall portion I of said electron discharge vessel.

6; In; an electron .discharge'vessel for emitting electrons; into the space outside; said vessel an electrontransmitting window in-the- Wall of said discharge: vessel, said-electron transmitting window comprising a. thin wall portion of an electron transmitting electrically non-conductive material; andiazflat'accel'erating electrode gridforming:a pluralityofgridiapertures. for the passage of electrons being--. arranged adjacent to. that surface of i said; thinwall partion which 2 is inside. said electron; discharge vessel, .saidlfiat acceleratingelectrod'e grid'being' sealed'to said thin wall portion: forming one single: unit with the same 'and'thus supporting saidzthin wall portion-of said electron: discharge; vessel.

7.1 Inian: electron discharge. vessel for emitting electrons into the space: outside said vessel, an

eletrontransmitting window.- in the: wall of said discharge. vessel; said electrontransmitting wine dow. comprisingzathin glass wall: portion, and a flatv acceleratin electrode: provided: with a plurality of apertures for-the passage ofelectrons arranged; inside said discharge vessel= adjacent to'said'thin' glass wall :portionsealed to and forming Onecsihgleuhit with thesame: and thus supporting 'said thin wall portion of saidelectron discharge vessel.

81 Intan. electrondischargevessel for emitting. electrons into thefispace' outside said. vessel an.

electrontransmitting windowinthe wallof said discharge vessel, saidzelectron transmitting window: comprising. athin glassxwall portionyand:

3; In: an electron discharge vessel -for' emitting: electrons intothe space 0utside='-said vessel an electron transmittingrwindow in the wallet i said I discha-rgevvessel, said electron: trans!hittingv winit dow comprising a thinwall portion of an elecfor: emitting electrons intnthe: space outside said: vessel an; electrontransmittingv wind-ow inlthe wall of said a thin accelerating electrode plate provided with a pluarlity of small apertures for the passage of electrons arranged within said discharge vessel adjacent to said thin glass wall portion sealed to and forming one single unit with the same,

and thus supporting said thin wall portion of said electron discharge vessel.

9. In an electron discharge vessel for emitting electrons into the space outside said vessel an electron transmitting window in the wall of said discharge vessel, said electron transmitting window comprising a thin glass wall portion and a flat accelerating electrode grid forming a plurality of grid apertures for the passage of electrons being arranged in said discharge vessel covering said thin glass wall portion and being sealed to the same and thus supporting said thin Wall portion of said electron discharge vessel.

10. In an electron discharge vessel for emitting electrons into the space outside said vessel an electron transmitting window in the wall of said discharge vessel, said electron transmitting window comprisin a thin wall portion of an electron transmitting electrically non-conductive material, and a flat accelerating electrode consisting of an electrically conductive material ex panding when exposed to temperature variations in the same way as the material of which said thin wall portion consists, said fiat accelerating electrode being provided with a plurality of apertures for the passage of electrons and being arranged inside said discharge vessel adjacent to said thin wall portion, sealed to said thin wall portion and forming one single unit with the'same and thus supporting said. thin wall portion of said electron discharge vessel.

11. In an electron discharge vessel for emitting electrons into the space outside said vessel an electron transmitting window in the wall of said discharge vessel, said electron transmitting window comprising a thin wall portion of an electron transmitting electrically non-conductive material, and a thin accelerating electrode-plate consisting of an electrically conductive material having the same temperature coefficient as said electrically non-conductive material of which said thin wall portion consists, said'thin accelerating electrode platebeing provided with a plurality of apertures for the passage of electrons and being arranged inside said discharge vessel adjacent to said thin wall portion, sealed to said ing the same temperature coefficient as said electrically non-conductive material of which said thin wall portion consists, said flat acceleratingelectrode grid forming a plurality of grid apertures for the passage of electrons and being arranged inside said discharge vessel adjacent to said thin wall portion, sealed to said thin wall portion and forming one single unit with the same and thus supporting said thin wall portion of said electron discharge vessel.

13. In an electron discharge vessel for emitting electrons into the space outside said vessel an electron transmitting window in the wall of said discharge vessel, said electron transmitting window comprising a thin glass wall portion, and a fiat accelerating electrode consisting of a metal havingthe same temperature coeflicient as said glass of which said thin glass wall portion consists, said flat accelerating electrode being provided with a plurality of apertures for the pas-. sage of electrons and being arranged inside said discharge vessel adjacent to said thin wall portion, sealed to said thin wall portion and form-- ing one single unit with the same and thus supporting said thin wall portion of said electron discharge vessel.

14. In an electron discharge vessel for emitting z electrons into the space outside said vessel an side said discharge vessel adjacent to said thin wall portion, sealed to said thin wall portion and forming one single unit with the same and thus supporting said thin wall portion of said electron discharge vessel.

15. In an electron discharge vessel for emitting electrons into the space outside said' vessel an electron transmitting window in the Wall of said discharge vessel, said electron transmitting window comprising a thin glass wall portion, and a flat accelerating electrode grid consisting of a metal having the same temperature coeflicient as said glass of which said thin glass wall portion consists, said flat accelerating electrode grid forming a plurality of grid apertures for the passage of electrons and being arranged inside said discharge vessel adjacent to said thin wall portion,-sealed to said thin wall portion and forming one single unit with the same and thus sup porting said thin wall portion of said electron discharge vessel.

16. In an electron discharge vessel for emittin electrons into the space outside said vessel an electron transmitting window in the wall of said discharge vessel, said electron transmitting-window comprising a thin lead glass wall portion, and a flat accelerating electrode consisting of an alloy having the same temperature coefiicient as said lead glass of l which said thin lead glass wall portion consists, said flat accelerating electrode being provided with a plurality of apertures for the passage of electrons and being arranged inside said discharge vessel adjacent to said thin wall portion, sealed to said thin wall portion and forming one single unit with the same and thus supporting said thin wall portion of said electron discharge vessel.

1'7. In an electron discharge vessel for emitting electrons into the space outside said vessel an electron transmitting window in the wall of said discharge vessel, said electron transmitting window comprising a thin lead glass wall portion, and a thin accelerating electrode plate consisting of an alloy having the same temperature coefiicient as said lead glass of which said thin lead glass wall portion consists, said thin accelerating electrode plate being provided with a plurality of apertures for the passage of electrons and being arranged inside said discharge vessel adjacent to said thin wall portion, sealed to said thin wall portion and forming one single unit with the same discharge vessel, said electron transmitting window comprising a thin lead glass wall portion, and a flat accelerating electrode grid consisting of an alloy having thesame temperature coefficient as said lead glass of which said thin lead glass wall portion consists, said flat accelerating electrode grid forming a plurality of grid apertures for the passage of electrons and being an discharge vessel, said electron transmitting window comprising a thin lead glass wall portion, and

a thin accelerating electrode plate consisting of,

an alloy comprising mainly nickel, iron, chromium, and traces of cobalt, said thin accelerating electrode plate being provided with a plurality of apertures for the passage of electrons and being arranged inside said discharge vessel adjacent to said thin wall portion, sealed to said thin wall portion and forming one single unit with the same and thus supporting said'thin wall portion of said electron discharge vessel.

20. In an electron discharge vesselfor emitting electrons into the space outside said vessel an electron transmitting window in the wall of said discharge vessel, said electron transmitting wiridow comprising a thin lead glass wall portion, and a flat accelerating electrode grid consisting of an alloy comprising mainly nickel, iron, chromium, and traces of cobalt, said'flat accelerating electrode grid forming a plurality of grid apertures for the passage of electrons and being arranged inside said discharge vessel adjacent to said thin wall portion, sealed to said thin wall portion and forming one single unit with the same and thus supporting said thin wall portion of said electron discharge vessel.

HENRY ALFRED DE PHILLIPS.