Letter | Published:

Electron Multiplier as an Electron Counting Device

Nature volume 141, page 1011 (04 June 1938) | Download Citation



IN an earlier communication1, I have described the possibility of using an electron multiplier, based on the secondary emission principle, for the detection of individual electrons by cooling the multiplier for the purpose of suppressing the thermal emission in liquid air. I stated there that this method of counting individual electrons does not necessarily require the use of liquid air, provided multiplying electrodes, with fairly great secondary emission factor and sufficiently high work function are used. There is a large discrepancy in the data of various papers published on the subject of work function and secondary emission of a surface. Experiments had to be carried out to determine whether a surface satisfying our requirements could be found, and we found the following surface satisfactory from the above point of view:

Very thin layers of barium oxide on a nickel base activated by the method normally used for oxidecoated cathodes will easily give a multiplication factor of T = 2·5, with a primary electron velocity of 200 volts. A multiplication of about 10,000 times was achieved in a ten-stage multiplier. The thermionic emission (at room temperature) and field emission of the active surfaces in this multiplier are negligible.

Access optionsAccess options

Rent or Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.


  1. 1.

    , NATURE, 141, 287 (1938).

Download references

Author information


  1. Tungsram Research Laboratories, United Incandescent Lamps and Electrical Company, Ujpest, nr. Budapest. April 25.

    • Z. BAY


  1. Search for Z. BAY in:

About this article

Publication history





By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.