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Title: Faraday cup with nanosecond response and adjustable impedance for fast electron beam characterization

Abstract

A movable Faraday cup design with simple structure and adjustable impedance is described in this work. This Faraday cup has external adjustable shunt resistance for self-biased measurement setup and 50 {Omega} characteristic impedance to match with 50 {Omega} standard BNC coaxial cable and vacuum feedthroughs for nanosecond-level pulse signal measurements. Adjustable shunt resistance allows self-biased measurements to be quickly acquired to determine the electron energy distribution function. The performance of the Faraday cup is validated by tests of response time and amplitude of output signal. When compared with a reference source, the percent difference of the Faraday cup signal fall time is less than 10% for fall times greater than 10 ns. The percent difference of the Faraday cup signal pulse width is below 6.7% for pulse widths greater than 10 ns. A pseudospark-generated electron beam is used to compare the amplitude of the Faraday cup signal with a calibrated F-70 commercial current transformer. The error of the Faraday cup output amplitude is below 10% for the 4-14 kV tested pseudospark voltages. The main benefit of this Faraday cup is demonstrated by adjusting the external shunt resistance and performing the self-biased method for obtaining the electron energy distribution function. Resultsmore » from a 4 kV pseudospark discharge indicate a ''double-humped'' energy distribution.« less

Authors:
;  [1]
  1. Missouri University of Science and Technology (Formerly University of Missouri-Rolla), Rolla, Missouri 65409 (United States)
Publication Date:
OSTI Identifier:
22063686
Resource Type:
Journal Article
Journal Name:
Review of Scientific Instruments
Additional Journal Information:
Journal Volume: 82; Journal Issue: 7; Other Information: (c) 2011 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0034-6748
Country of Publication:
United States
Language:
English
Subject:
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY; 43 PARTICLE ACCELERATORS; AMPLITUDES; COAXIAL CABLES; ELECTRIC CURRENTS; ELECTRIC POTENTIAL; ELECTRON BEAMS; ELECTRONS; ENERGY SPECTRA; FARADAY CUPS; IMPEDANCE; PULSES; SIGNALS; TRANSFORMERS

Citation Formats

Hu Jing, and Rovey, Joshua L. Faraday cup with nanosecond response and adjustable impedance for fast electron beam characterization. United States: N. p., 2011. Web. doi:10.1063/1.3610649.
Hu Jing, & Rovey, Joshua L. Faraday cup with nanosecond response and adjustable impedance for fast electron beam characterization. United States. doi:10.1063/1.3610649.
Hu Jing, and Rovey, Joshua L. Fri . "Faraday cup with nanosecond response and adjustable impedance for fast electron beam characterization". United States. doi:10.1063/1.3610649.
@article{osti_22063686,
title = {Faraday cup with nanosecond response and adjustable impedance for fast electron beam characterization},
author = {Hu Jing and Rovey, Joshua L.},
abstractNote = {A movable Faraday cup design with simple structure and adjustable impedance is described in this work. This Faraday cup has external adjustable shunt resistance for self-biased measurement setup and 50 {Omega} characteristic impedance to match with 50 {Omega} standard BNC coaxial cable and vacuum feedthroughs for nanosecond-level pulse signal measurements. Adjustable shunt resistance allows self-biased measurements to be quickly acquired to determine the electron energy distribution function. The performance of the Faraday cup is validated by tests of response time and amplitude of output signal. When compared with a reference source, the percent difference of the Faraday cup signal fall time is less than 10% for fall times greater than 10 ns. The percent difference of the Faraday cup signal pulse width is below 6.7% for pulse widths greater than 10 ns. A pseudospark-generated electron beam is used to compare the amplitude of the Faraday cup signal with a calibrated F-70 commercial current transformer. The error of the Faraday cup output amplitude is below 10% for the 4-14 kV tested pseudospark voltages. The main benefit of this Faraday cup is demonstrated by adjusting the external shunt resistance and performing the self-biased method for obtaining the electron energy distribution function. Results from a 4 kV pseudospark discharge indicate a ''double-humped'' energy distribution.},
doi = {10.1063/1.3610649},
journal = {Review of Scientific Instruments},
issn = {0034-6748},
number = 7,
volume = 82,
place = {United States},
year = {2011},
month = {7}
}