Review of Scientific Instruments
Feedback | Help | Exit
Review of Scientific Instruments
Search:
   
 
 
 
Previous Article
A Phase-Shift Refractometer
This paper describes a refractometer for measuring small changes in the dielectric constant or index of refraction of atmospheric air. The method employed is that of measuring the change in phase of a...
Next Article
A New Type of Electromagnet. Part I. Operation at 20-kw Level
An improved iron core magnet for general laboratory use, weighing two tons, has been designed and several units have been constructed. The design incorporates the desirable features of a number of ear...

Magnetic Electron Multipliers for Detection of Positive Ions

Rev. Sci. Instrum. 22, 166 (1951); doi:10.1063/1.1745871

Issue Date: March 1951

You are not logged in to this journal. Log in

Lincoln G. Smith
Brookhaven National Laboratory, Upton, Long Island, New York
Two designs of 15-stage electron multiplier wherein focusing from one beryllium copper dynode to the next occurs in crossed electric and magnetic fields have been developed particularly for detection of weak beams or pulses of positive ions in magnetic fields. One, with dynodes [fraction three-eighths] in. wide, is usable in fields between about 250 and 460 oersteds while the other, with dynodes [fraction one-eighth] in. wide, is usable in fields between about 300 and 1100 oersteds. It appears likely that, by using still narrower dynodes, such multipliers can be constructed to operate in fields of several thousand oersteds. Advantages of these designs over previously described multipliers employing crossed fields are the use of about half the number of insulated plates and less tendency, because of uniformity of the electric field, for breakdown and noise, due to ion feedback, to occur. The uniformity of the electric field also allows quite reliable calculation of the spread in transit time. From this it is concluded that, with a modified collecting system, a multiplier could be built with a rise time between 10−11 and 10−10 sec, which is very probably less than could be obtained with a static multiplier. Review of Scientific Instruments is copyrighted by The American Institute of Physics.
History: Received September 25, 1950
Permalink: http://link.aip.org/link/?RSINAK/22/166/1
BUY THIS ARTICLE   (US$24)
Download PDF (651 kB) View Cart

RELATED DATABASES


To view database links for this article,
you need to log in.
To view database links for this article,
you need to log in.

PUBLICATION DATA

ISSN:
0034-6748 (print)   1089-7623 (online)
Publisher:
AIP is a member of CrossRef AIP

REFERENCES (15)
View in Separate Window/Tab
For access to fully linked references, you need to log in. For access to fully linked references, you need to Log in.
  1. S. A. Goudsmit, Phys. Rev. 74, 622 (L) (1948).
  2. Paul I. Richards and E. E. Hays, Rev. Sci. Instr. 21, 99 (1950).
  3. Throughout this paper the term “magnetic multiplier” will be used to designate the multiplier that employs crossed electric and magnetic fields to achieve focusing from dynode to dynode. The type employing grids between which electric fields are established parallel to a magnetic field will not be considered.
  4. Lincoln G. Smith, Rev. Sci. Instr. (to be published).
  5. In relations (1) to (3c), the undefined symbols have their usual meanings and E is expressed in volts/cm while H is in oersteds.
  6. In Reference 1, the coefficient 652 is erroneously given as 670.
  7. Walker, Bleakney, and John A. Hipple, Jr., Phys. Rev. 53, 521 (1938).
  8. V. K. Zworykin, G. A. Morton, and L. Malter, Proc. Inst. Radio Engrs. , 24, 351 (1936).
  9. So far as I am aware, all previous designs have been based on that described in Reference 8. Magnetic multipliers of this type have also been described by W. H. Rann, J. Sci. Instr. 16, 241 (1939),
    10. by J. Coutancier, Rev. gén. élec. 48, 31 (1940),
    and by H. Schnitger, Electrotech. Z. 63, 41 (1942).
  10. Calculations of orbits in the non-uniform electric field between a simplified configuration of electrodes of this general type has been made by D. Charles, Compt. Rend. 216, 556 (1943). These show the space focusing to be materially worse than if the electric field is assumed to be uniform.
  11. James S. Allen, Rev. Sci. Instr. 18, 739 (1947).
  12. R. Kollath, Ann. Physik 436, 357 (1947).
  13. I am indebted to Dr. Earl Hays of this laboratory for suggesting employment of this feature.
  14. It should be noted that extra high potentials, but no extra power, are required for the rail plate (or plates). Design MI requires no more overall voltage than the design of Reference 8 while MII does require somewhat more.
  15. The rise time of a static multiplier has been determined to be <5×10−9 sec (G. Papp, Rev. Sci. Instr. 19, 568 (1948)).

CITING ARTICLES
For access to citing articles, you need to log in.
For access to citing articles, you need to Log in.


Copyright © American Institute of Physics