Department seminar

Date and time: 11 May 2016 (Wednesday), 4:00 pm
Venue: Seminar Hall

Title: Electron imaging with a microchannel plate detector

Speaker: Dr. Devinder Siwal, Post Doctoral Fellow, Dept. of Physics, Indiana University, Bloomington, USA

Abstract: In this talk I would summarize the research work which I have pursued at Indiana University, Bloomington, USA, for a research project dealing with a microchannel plate detector (MCP). A MCP detector has proven its capability to detect the incident electrons, photons, and ions with high resolving power in space, at the same time maintaining the temporal resolution of ∼100-300 ps. It can be used in variety of applications such as γ-ray tomography, neutron imaging, radioactive ion beam imaging, 3D atom probe tomography, astronomy etc. MCP detector can also be used as a optical image intensifier (with a exponential multiplication of the incident electron intensity) used in night vision goggles. Geometrical parameters of a MCP determines the intrinsic spatial and temporal characteristics of an electron cloud emanates from the exit surface. This charge cloud can be triggered by the incident electron, whose position is determined by a sense wire (or Resistive Anode) detector, providing the position resolution (FWHM) of 466 μm. A detailed study of the charge cloud radius has been performed with a simple slice current model to get the quantitative measure of electron charge cloud size. Results are used to optimize the position resolution of a resistive anode (RA) detector place behind the MCP detector. Further efforts are made to minimize the position resolution by digital pulse processing and Pulse Shape Analysis of RA detector. A simple analysis, by using joint use of risetime and charge division of RA signals reveals the position resolution (FWHM) of 64 μm which is comparable to more complex arrangement of MCP and RA detector.