Monte Carlo Simulations of Microchannel Plate Detectors II: Pulsed Voltage Results

Journal Article · Fri Feb 11 00:00:00 EST 2011 · Review of Scientific Instruments

DOI:https://doi.org/10.1063/1.3530451· OSTI ID:1055237

Kruschwitz, Craig A. ^[1]; Wu, Ming ^[1]; Rochau, Greg A. ^[2]

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1. National Security Technologies, LLC. (NSTec), Los Alamos, NM (United States)
2. Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

This paper is part of a continuing study of straight-channel microchannel plate (MCP)–based x-ray detectors. Such detectors are a useful diagnostic tool for two-dimensional, time-resolved imaging and time-resolved x-ray spectroscopy. To interpret the data from such detectors, it is critical to develop a better understanding of the behavior of MCPs biased with subnanosecond voltage pulses. The subject of this paper is a Monte Carlo computer code that simulates the electron cascade in a MCP channel under an arbitrary pulsed voltage, particularly those pulses with widths comparable to the transit time of the electron cascade in the MCP under DC voltage bias. We use this code to study the gain as a function of time (also called the gate profile or optical gate) for various voltage pulse shapes, including pulses measured along the MCP. In addition, experimental data of MCP behavior in pulsed mode are obtained with a short-pulse UV laser. Comparisons between the simulations and experimental data show excellent agreement for both the gate profile and the peak relative sensitivity along the MCP strips. We report that the dependence of relative gain on peak voltage increases in sensitivity in pulsed mode when the width of the high-voltage waveform is smaller than the transit time of cascading electrons in the MCP.

• Research Organization: Nevada Test Site (NTS), Mercury, NV (United States)
• Sponsoring Organization: USDOE National Nuclear Security Administration (NNSA)
• DOE Contract Number: AC52-06NA25946
• OSTI ID: 1055237
• Report Number(s): DOE/NV/25946-1075
• Journal Information: Review of Scientific Instruments, Vol. 82, Issue 2; ISSN 0034-6748
• Publisher: American Institute of Physics (AIP)
• Country of Publication: United States
• Language: English