US2786156A - Corpuscular beam apparatus - Google Patents

Description

219"121 Sire w C MTROS March lg, 195-? 2,786,156

A. LORENZ CORPUSCULAR BEAM APPARATUS Filed Dec. 29, 1953 FiG. I.

INVENTOR ALBERT LORENZ BY 7 M ATTORNEYS iinited States Patent 6 CORPUSCULAR BEAM APIARATUS Albert Lorenz, Hanan (Main), Germany, assignor to W. C. Heraeus G. in. b. H., Hanan (Main), Germany, a German body corporate Application December 29, 1953, Serial No. 400,986

Claims priority, application Germany January 9, 1953 15 Claims. (Cl. 313-63) consisting of compact matter, for example, of metal foil,

and the generally detrimental heating of parts of the apparatus resulting therefrom and generally to make available in a reaction chamber or working chamber a sharply concentrated unweakened corpuscular beam.

A further object is not only to reduce to the largest possible extent anyv dilfusion and also collision of the corpuscular beams with gas molecules but also to prevent gases, vapours, or dust particles participating in the reaction which takes place in the working chamber under, for example, atmospheric pressure from being lost by diffusion in a direction opposite to the direction of the beam and exerting a detrimental influence upon sensitive parts of the apparatus;

The improved corpuscular beam apparatus according to the invention, which serves for producing high energy transformations, adapted to be controlled in an inertialess manner, in sharply localised parts of space comprises, on the one hand, a known per se source of corpuscular radiation located within a chamber that is under highvacuum pressure and is closed apart from an aperture for the passage of the corpuscular beam, with known per se devices for the concentration and focussing of the corpuscular beams and a reaction chamber connected in series with it in the direction of the corpuscular beam, said reaction chamber having a relatively high gas density comparable with atmospheric pressure, and on the other hand, a pressure-stage system interposed between the said two chambers and having at least two pressure-stage chambers of a pressure increasing step by step, said pressure-stage chambers being arranged in series with each other with partition walls between the individual chambers, these walls having fine bores aligned in the direction of the corpuscular beam so that the concentrated corpuscular beam may pass through the aligned bores without being impeded by any compact matter, at least the last pressure stage chamber which is arranged immediately in front of the reaction chamber being arranged to serve as a protective chamber by being filled with a gas not disadvantageously influencing the reaction in the working chamber and having a pressure which is at least equal to that prevailing in the working chamber, and all individual chambers being connected to devices serving for the production and generation of the gas densities corresponding to the required pressure ratio or arranged to form part of the passages through which the reaction partners participating in the energy transformations are supplied and withdrawn. The term reaction partners in this specification should be understood to describe 2,786,155 Patented Mar. 19, 1957 any substance participating in or formed by the reaction in the working chamber.

The corpuscular beam apparatus according to the invention shall now be explained with reference to the accompanying drawing, the Figures 1 and 2 of which respectively show two embodiments in a schematic manner.

in one simple embodiment, illustrated in Fig. 1, the main components of the apparatus are arranged in a housing 22 closed in a vacuum-proof manner and include a chamber 1 containing the source of radiation 2, at least one pressure-stage chamber 5, the reaction chamber 7, and finally the interposed protective or lock chamber 6. in the radiation generation chamber 1 there is generally a high vacuum, that is to say, a pressure lower than 1 Torr., which is generated and maintained by a pump 10 connected thereto. For the generation of the corpuscular beam 3 one of the known cathode, anode or canal (ion) ray sources, for example, an incandescent cathode and, in addition to the further known per se means 4 for the acceleration of these rays in the desired-direction of the beam also electrostatic or magnetic electronoptical devices with their current supply lines 4a, which permit the corpuscular beam to be concentrated and to be focussed.

It should be understood that the term electronoptical device is used in the present specification irrespective of whether the afifected radiation consists of electrons or ions. Since high voltages are required for the acceleration of the beam, special care is required to ensure a wellinsulated introduction of the current supply conductors 2a. The pressure-stage chamber 5 is connected to a further vacuum pump 11 in order that a gas pressure intermediate between 1 Torr. and atmospheric pressure may be produced and maintained, while the protective chamber 6, in which a substantially higher gas density, exceeding in some cases even the pressure in the reaction chamber 7, is required to prevail, communicates in the illustrated example with the external atmosphere through a connecting stud 12; the gas pressure required inrthe reaction or working chamber 7 is controlled by suitable devices, represented in the illustrated example, by the pipe conduits 8a and 8b, equipped with regulating valves 9:: and 9b, through which the substances participating in the reaction or the reaction products are supplied or withdrawn, and which at the same time serve for the maintenance of the desired gas pressure.

The apertures 19, 20 and 21, for: the passage of the corpuscular beam 3 from the beam generation chamber into the pressure-stage chamber and, from the latter into the reaction chamber are not, as hitherto usual, sealed by compact windows consisting, e. g., of metal foil, but are formed as fine bores or nozzles aligned with the corpuscuiar beam and having a diameter of fractions of a millimetre. It is advantageous for these fine passage apertures to be provided not direct in the partition walls but in diaphragms which are arranged in the partition walls at the points 19, 20 and 21 so that interchangeable diaphragms with holes of diiferent diameters may be employed. By the fact that the gas pressure in the protective lock chamber 6 is equal or higher than in the reaction chamber, the gaseous, vapourised or pulviform reaction partners participating in the reaction which takes place within extremely narrow space limits at 18 are prevented from penetrating in adirection opposite to that of the beam, through the fine nozzle apertures into the various series-connected pressure-stage chambers and reaching the source of radiation, which would not only lead to contamination, blocking or enlargement of the fine nozzle bores by reaction products becoming attached by suction to the walls of the bores or even reacting with the material of the'diaphragms and afiecting the surface quality, but might even reduce the output of the source of radiation and deteriorate insulation by forming conductive deposits.

The dimensions of the protective chamber 6 and of the line passage apertures. between the protective cham-. her on the one hand and the pressure-stage. chamber andthereaction chamber 7 onv the other hand are chosen only just large enough to:ensure the desired. lock effect. For example, the protective chamber needin many cases not be longer than 1 mm;, and the bore 20 leading to the next following pressure-stage chamber 5 need not be wider than()'.5 mm. The. passage aperture 21 leading to the reaction chamber may advantageously have a somewhat larger diameter inorder that the. corpuscular beam, which will sufiEer a certain amount of diffusion in the protective chamber due; to, the higherpressure there prevailing, may pass unobstructed. In any case, the invention obtains its technical importance. by the incorporation of a protective chamber between the pressure-stage chamber or chambers proper and the reaction chamber, since itis only when such av chamber is provided that it is possible for chemical reactions to be started or. maintained in: thereaction chamber within a narrowly confined-space portion 18 with the help of the corpuscular beam' as without incurring the. risk of detrimental influencesbeing exerted by reaction. partners upon the remainder of the apparatus. The protective chamber 6 may be filled with a gas that participates in the reaction occurring at 18: It is advisable for the protective chamber 6-to-be filled'with air or a different (inert) gas by the chamber 6 communicating through the stud 12 with a gas container. Particularly suitable for use in the protective chamber are also rare gases since these, apart from ionization, cannot sutfer any chemical modification by the action of thepassing corpuscular beam. In a number of cases of practical importance, however, an air filling withdirect connection of the protective chamber to the atmosphere is sufiicient.

Fig. .2 illustrates another embodiment of a corpuscular beam apparatus according tothe invention. In this modified embodiment, 5- communication passage 12a feeds the quantity of gas which has been withdrawn from the pressure-stage'chamber 5 bymeans of the pump 11, back to theprotective chamber 6-sothat in the latter a higher gas. pressure will be obtained which generally also exceeds that prevailing in the reaction chamber 7'. This: construction is particularly recommended when using indifierent (inert) gases, particularly rare gases, as filling of: the protective chamber, since in that case 95 to 99% of the quantityof gas penetrating from the protective chamber 6' through the aperture 20 into the pres sure-stage chamber 5 is pumped back again instead of being lost. A small residue will, however, flow through the fine'aperture 19-into the beam-generating chamber 1 and isthen-removed by the pump 10. This small loss is advantageously'made good by the controlled admission of further [gas quantities from the supply container 17 tlrough a communication passage equipped. with a valve 1 Inorder to reduce further the thickness of the layer of gas through which the corpuscular beam 3 passes on its way between the source of radiation 2 and theworking= chamber 18 and thereby further to reduce the already small diffusion losses still caused thereby, the length of the whole apparatus, and more particularly the thickness of the individual chambers, should be kept as small as possible. Further while the partition walls between the individual chambers may be plain they may alternatively be funnel-shaped; In many cases it is furthermore advisable to provide cooling arrangements for the partition walls or to form the partition walls additionally also as electric or magnetic deflector elements. Even the protective chamber may additionally be utilised for the incorporation of known per se beam deflecting or concentrating means. The walls and partitions may consist of metal, glass, quartz glass, or ceramic substances.

The insertion, according to the invention, of a protec tive chamber blocking the How of gas from the reaction chamber is recommended in all cases of the use of a beam device that is equipped with pressure-stage chambers instead of material windows, when beams of corpuscular radiation are intended to be used. Such beams may not only be employed for the generation of heat in narrowly confined small spaces, for example, for burner cutting or. for thermic. blasting of. holes in metallic and non-metallic objects, and for melting, evaporating, and sublimating dllicultly melting substances, but also for the priming andmaintenance of chemical reactions, and further for the generation of thermic pressure pulses and sound oscillations for the.- measurement of temperatures and gas densities, and for the generation of X-rays of vacuum-sensitive susbtances, and finally also for radiation-optical and medical purposes. The protective chamber according to the. invention in these cases prevents the entry of the gases, vapours, or dust-particles participating in or produced by these. reactions into. the. pressure-stage. stretch and beam generating device: thus protecting the whole apparatus with the result of greater reliability and: a longer operative life.

I claim;

l. A. corpuscular beam, apparatus for producing spatially localised. high. energy transformations in narrowly. confined space. portions, comprising in combination a receptacle containing afirst chamber under high vacuum pressure, a. source of a beam of corpuscular radiation arranged in said chamber,. the. chamber being closed,

apart from an aperture for the passage of the corpuscular beam, means associated with the chamber for concentrating and focussi-ng the corpuscular beams, said receptacle further containinga; reaction-chamber, placed in line with said first chamber inthe direction of the corpuscular beam, means for maintaining in said reaction chamber a comparatively high gas density comparable with atmospheric pressure, a. pressure-stage. system formed in said receptacle so as to be, interposed between the two said chambers, said pressure-stage system. including at least two pressure-stage. chambers separatedby. partition walls and arranged in series, the last one of said pressure-stage chambers. immediately; preceding the. reaction chamber beinga protective chamber andsaid-partition-walls being provided with fine bores aligned in relation to the corpuscular beam so that the concentrated corpuscular beamtmay pass through the. aligned bores unimpeded by any compact matter; means for maintaining in said first chamber and: in the pressure-stage chambers diiferent pressures increasingfrom high vacuum pressure step by step in the. direction ofthebeam, and means for maintaining in. at least said protective chamber a gas. not disadvantageously influencing the reactiorrin the operating. chamber and under apressure which is at: least equal to that prevailing in the operating chamber.

2; Acorpuscular beam.apparatusas-claimedinclaim 1, wherein the means for maintaining the gas pressure in at least one pressure-stage chamber include means for passing. through said chamber at least one reaction partner of an energy transformation efiected in the working chamber.

3. A corpuscular beam apparatus as claimed in claim 1. characterised. in-that the protective chamber is formed with a passage through which it communicates direct with the external atmosphere.

4. A corpuscular beamapparatus as claimed in claim 1, comprising a= pump serving-for the evacuation of the pressure-stage chamber arranged. before the protective chamber, the latter being connected to the pressure side of said pump so that gas penetrating into the pressure stage system from the protective chamber is at least partly reintroduced into the protective chamber.

5. A corpuscular beam apparatus asclaimed in claim 4. further comprising a gas supply reservoir, conduit, means through which said reservoir communicates with the outermost pressure-stage chamber, and a regulable valve in said conduit means.

6. A corpuscular beam apparatus as claimed in claim 1, characterised in that at least some wall parts of the protective and pressure-stage chambers are constructed to constitute electronoptical means for influencing the beam.

7. A corpuscular beam apparatus as claimed in claim 1, further comprising electronoptical means for influencing the beam, said electronoptical means being arranged in the protective chamber.

8. A corpuscular beam apparatus as claimed in claim 1, characterised in that the protective chamber is so constructed that the length of path of the corpuscular beam across said chamber does not substantially exceed 1 mm.

9. A corpuscular beam apparatus as claimed in claim 1, characterised in that the protective chamber and the last pressure stage chamber has a bore for the passage of the corpuscular beam, the partition between this bore having a diameter not wider than 0.5 mm.

10. A corpuscular beam apparatus as claimed in claim 9, characterised in that the partition between the reaction chamber and the protective chamber has a bore, not less than 0.5 mm. in diameter, for the passage of a corpuscular beam.

11. A corpuscular beam apparatus as claimed in claim 1, characterised in that the partition between the reaction chamber and the protective chamber has a bore, not less than 0.5 mm. in diameter, for the passage of a corpuscular beam.

12. A corpuscular beam apparatus as claimed in claim 1, characterised by means for filling the protective chamber With a gas of higher pressure than that prevailing in the reaction chamber.) f

13. A corpuscular beam apparatus as claimed in claim 12, characterised by means for filling the protective chamber with a gas which will not affect or be atfected by the reaction taking place in the reaction chamber.

14. A corpuscular beam apparatus as claimed in claim 1, characterised by means for filling the protective chamber with a noble gas.

15. A corpuscular beam apparatus as claimed in claim 1, characterised by means for filling the protective chamber with a gas'which constitutes one of the substances participating in the reaction taking place in the reaction chamber.

References Cited in the file of this patent UNITED STATES PATENTS 2,570,124 Hernqvist Oct. 2, 1951 2,640,948 Burrill June 2, 1953 2,643,341 Leland June 23, 1953

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