US2189971A - Secondary electron emitting electrode - Google Patents
Secondary electron emitting electrode Download PDFInfo
- Publication number
- US2189971A US2189971A US169172A US16917237A US2189971A US 2189971 A US2189971 A US 2189971A US 169172 A US169172 A US 169172A US 16917237 A US16917237 A US 16917237A US 2189971 A US2189971 A US 2189971A
- Authority
- US
- United States
- Prior art keywords
- secondary electron
- electron emitting
- emitting electrode
- copper
- curve
- 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
Links
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 7
- 229910052802 copper Inorganic materials 0.000 description 7
- 239000010949 copper Substances 0.000 description 7
- 229910052751 metal Inorganic materials 0.000 description 6
- 239000002184 metal Substances 0.000 description 6
- ATBAMAFKBVZNFJ-UHFFFAOYSA-N beryllium atom Chemical compound [Be] ATBAMAFKBVZNFJ-UHFFFAOYSA-N 0.000 description 5
- 229910045601 alloy Inorganic materials 0.000 description 4
- 239000000956 alloy Substances 0.000 description 4
- 229910052790 beryllium Inorganic materials 0.000 description 4
- 229910000952 Be alloy Inorganic materials 0.000 description 3
- 229910052792 caesium Inorganic materials 0.000 description 2
- TVFDJXOCXUVLDH-UHFFFAOYSA-N caesium atom Chemical compound [Cs] TVFDJXOCXUVLDH-UHFFFAOYSA-N 0.000 description 2
- QSHDDOUJBYECFT-UHFFFAOYSA-N mercury Chemical compound [Hg] QSHDDOUJBYECFT-UHFFFAOYSA-N 0.000 description 2
- 229910052753 mercury Inorganic materials 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- 229910000881 Cu alloy Inorganic materials 0.000 description 1
- 229910052783 alkali metal Inorganic materials 0.000 description 1
- 150000001340 alkali metals Chemical class 0.000 description 1
- 239000002585 base Substances 0.000 description 1
- DMFGNRRURHSENX-UHFFFAOYSA-N beryllium copper Chemical compound [Be].[Cu] DMFGNRRURHSENX-UHFFFAOYSA-N 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 229910052709 silver Inorganic materials 0.000 description 1
- 239000004332 silver Substances 0.000 description 1
- 238000007669 thermal treatment Methods 0.000 description 1
Images
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J1/00—Details of electrodes, of magnetic control means, of screens, or of the mounting or spacing thereof, common to two or more basic types of discharge tubes or lamps
- H01J1/02—Main electrodes
- H01J1/32—Secondary-electron-emitting electrodes
Definitions
- This invention relates to secondary electron emitting electrodesisuitable for use in so-called electron multipliers.
- a basis metal such as copper alloyed with a.
- metal having low work function such as beryllium.
- the above alloys is treated by heating in a high vacuum so as to drive off occluded gases. This process imparts a physical structure which greatly improves its secondary electron emission power.
- the proportion. of beryllium to the copper can be varied within fairly wide limits and maybe from 1% to 10% by weight of the alloy. 7
- the accompanying drawing shows curves connecting the secondary emission factor n (ratio of the number of secondary electrons emitted per incident primary electron) with velocity v (abscissae) of primary electrons expressed volts.
- the curves I, 2, 3, 4 and'5 were obtained with An electrode made of or covered with one of an electrode of an alloy of copper and beryllium with 2.4% of beryllium; the curve I at ordinary temperature, the curve 2 at 700 C., the curve 3 at 800C and the curve 4 at 900 C. In each case the electrode was first thermally treated and de- 5 gassed as above stated.
- Curve 5 was obtained for the same conditions as curve I that is to say cold, butafter 100 hours of operation.
- Curve 0 is a curve for pure copper. 1O
- a secondary electron emitting electrode for electron multipliers and the like having'asurface composed of an alloy of which the secondary electron emissivity is several times that of copper and is substantially independent of temperature and which consists of from 1% to 10% of berylliumand the balance of copper.
- a secondary electron emitting electrode for 3 electron multipliers and the like having a surface of high secondary electron emissivity and composed of a copper beryllium alloy consist ing of 2 beryllium and the balance copper.
Description
Feb. 13, 1940. I R WARNECKE 2,189,971
SECONDARY ELECTRON EMITTING ELECTRODES Filed Oct. 15, 1937 v COEFFICIENT OF SECONDARY ELECTRON EMISSION COPPER BERYLLIUM ALLOY 500 I I000 @500 p INVENTOR ROBERT WARNECKE BY ATTORNEY usual practice in electron multipliers to increase Patented Feb. 13, 1940 UNITED STATES PATENT OFFlCE SECONDARY ELECTRON EMITTING ELECTRODE Robert Warnecke, Paris, France, assignor to Compagnie Generale de Telegraphic Sans Fil,
a corporation of France Application October 15, 1937', Serial Ni), 169,172,
In France October 23, 1936 r 2 Claims. (Cl. 250-474) This invention relates to secondary electron emitting electrodesisuitable for use in so-called electron multipliers.
It is well known that most pure metals have rather slight secondary emission, and it is the the secondary electron emission by covering 'an ordinary metal electrodewith a layer of substance of more intense emission. For example, use has been made of a layer of a deposit of an alkali metal on an oxidised metal base, one
typical case being where caesium, oxide of caesium and silver are used.
ing good power of secondary emission while able to resist large rises of temperature.
In accordance with the invention use is made of a basis metal such as copper alloyed with a.
metal having low work function such as beryllium.
the above alloys is treated by heating in a high vacuum so as to drive off occluded gases. This process imparts a physical structure which greatly improves its secondary electron emission power. i
The proportion. of beryllium to the copper can be varied within fairly wide limits and maybe from 1% to 10% by weight of the alloy. 7
The accompanying drawing shows curves connecting the secondary emission factor n (ratio of the number of secondary electrons emitted per incident primary electron) with velocity v (abscissae) of primary electrons expressed volts. v
The curves I, 2, 3, 4 and'5 were obtained with An electrode made of or covered with one of an electrode of an alloy of copper and beryllium with 2.4% of beryllium; the curve I at ordinary temperature, the curve 2 at 700 C., the curve 3 at 800C and the curve 4 at 900 C. In each case the electrode was first thermally treated and de- 5 gassed as above stated.
Curve 5 was obtained for the same conditions as curve I that is to say cold, butafter 100 hours of operation.
Curve 0 is a curve for pure copper. 1O
These curves show that the secondary electron emissivity or multiplication effect does not;
exhibit appreciable fatigue and is practically independent of temperature up to about 1,000. The slight increase of the multiplication effect when 15 the temperature rises is probably attributable to the fact that the metal becomes gradually cleaner in proportion to the increase of temperature. l
The thermal treatment of the alloy for which curves I, 2, 3, 4, 5 were obtained, was carriedout as follows: the temperature was raised gradually (for about one hour) up to about 850 C. and
then maintained at this temperature for aboutv 2 /2 hours in a pressure below 8.10 mm. of mercury (during the first hour), the final pressur being less than 2.10-Tmm. of mercury.- I The power of secondary emission obtained is a little below that of electrodes covered with cer tain complex substances, but, on the other hand 30 the electrodes of this invention are moreeasy to manufacture and of much better thermal stability which last renders them very useful in high power v, tubes. i
i What I claim is:
1. A secondary electron emitting electrode for electron multipliers and the like having'asurface composed of an alloy of which the secondary electron emissivity is several times that of copper and is substantially independent of temperature and which consists of from 1% to 10% of berylliumand the balance of copper. 2. A secondary electron emitting electrode for 3 electron multipliers and the like having a surface of high secondary electron emissivity and composed of a copper beryllium alloy consist ing of 2 beryllium and the balance copper.
ROBERT WARNECKE
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| FR716974X | 1936-10-23 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| US2189971A true US2189971A (en) | 1940-02-13 |
Family
ID=9089828
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| US169172A Expired - Lifetime US2189971A (en) | 1936-10-23 | 1937-10-15 | Secondary electron emitting electrode |
Country Status (4)
| Country | Link |
|---|---|
| US (1) | US2189971A (en) |
| DE (1) | DE716974C (en) |
| FR (1) | FR824365A (en) |
| GB (1) | GB488688A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2585534A (en) * | 1945-11-07 | 1952-02-12 | Emi Ltd | Secondary electron emissive electrode and its method of making |
| US4792680A (en) * | 1987-01-12 | 1988-12-20 | Xerox Corporation | Corona device having a beryllium copper screen |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE744105C (en) * | 1939-09-14 | 1944-01-10 | Zeiss Ikon Ag | Process for increasing the secondary emission yield of secondary emission-capable layers |
| DE889812C (en) * | 1941-03-14 | 1953-09-14 | Telefunken Gmbh | Incandescent cathode for electric discharge tubes |
| NL97180C (en) * | 1953-05-21 |
-
1936
- 1936-10-23 FR FR824365D patent/FR824365A/en not_active Expired
- 1936-12-01 DE DES125152D patent/DE716974C/en not_active Expired
-
1937
- 1937-10-15 US US169172A patent/US2189971A/en not_active Expired - Lifetime
- 1937-10-18 GB GB28377/37A patent/GB488688A/en not_active Expired
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2585534A (en) * | 1945-11-07 | 1952-02-12 | Emi Ltd | Secondary electron emissive electrode and its method of making |
| US4792680A (en) * | 1987-01-12 | 1988-12-20 | Xerox Corporation | Corona device having a beryllium copper screen |
Also Published As
| Publication number | Publication date |
|---|---|
| GB488688A (en) | 1938-07-12 |
| DE716974C (en) | 1942-02-03 |
| FR824365A (en) | 1938-02-07 |
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