Open AccessOptical imaging of charged particle tracks in a gas. Final report
Author(s) -
James Turner,
R.N. Hamn,
S. R. Hunter,
William A. Gibson,
G. S. Hurst,
H.A. Wright
Publication year - 1995
Language(s) - English
Resource type - Reports
DOI - 10.2172/114038
Subject(s) - physics , detector , charged particle , optics , shutter , ionization , ionization chamber , particle detector , range (aeronautics) , alpha particle , image sensor , atomic physics , materials science , ion , quantum mechanics , composite material
The development of a new detector designed to optically image the track of a charged particle in a gas is outlined. In the detector, a pulsed high-voltage (up to {approx} 30--40 kV), high-frequency (f = 27.125 MHz) RF field is temporarily applied (pulse duration {approx} 1--3 {mu}s) across a pair of electrodes, immediately following, or alternatively, just prior to the passage of a charged particle through the chamber. The pulsed RF field excites the subexcitation electrons left along the particle`s path leading to excitation and ionization of the surrounding gas and the emission of light. The track is then imaged by a fast intensified digital camera (shutter speed {approx} 0.1--5 {mu}s). The image is recorded in a two-dimensional pixel array (512 {times} 512 pixels) within the camera, and transferred to a computer for later analysis. The detector has been operated over the total gas pressure range 2.5--100 kPa (20--750 torr) using a gas mixture of 2--10% N2 in Ar. Images of both {alpha} and {beta} tracks obtained with this detector are discussed to demonstrate the usefulness of the present technique in charged-particle track analysis for dosimetry and microdosimetry applications