A low pressure mercury vapor resonance ionization image detector

Abstract

Narrow-band spectrally selective image detection based upon the resonance ionization of mercury atoms in a low pressure cell is described. Image dimensions and intensities were measured versus the wavelength of ionizing laser radiation and the dependence upon the voltage applied to electrodes was studied. The position sensitive image of the electron beam, created by two-step resonance photoionization of mercury, was studied when the detected laser beam was scanned spatially. A distorting influence of space charge due to positive mercury ions on the electron beam image was observed. Means of eliminating these distortions are discussed.

Dual-Wavelength Time-Resolved Resonance Ionization Imaging with Cesium and Mercury Vapors

“…The configuration and detailed principle of operation of the RIID are described elsewhere. [1][2][3][4] Briefly, the detector, consisting of a partially metal coated input window and a microchannel plate coupled with a P20 phosphor screen, was assembled in a six-way cross-vacuum chamber. The chamber was evacuated to a pressure of ϳ1 torr.…”

“…The figure of merit of these detectors as well as their potential applications have been extensively discussed. 1 An RIID based on Hg vapor was first described by Matveev et al 2 and subsequently optimized by Pappas et al 3 Recently, another RIID using Cs as an active element was successfully demonstrated and its operational characteristics were evaluated. 4 The present note, as a continuation of the RIID development, describes a detector with two active elements (Cs and Hg), which exhibits dual-wavelength detection capability.…”

Direct visualization of molecular scale chemical adsorptions on solids using plasmonic nanoparticle arrays

“…A variety of techniques have been used to detect adsorbed species using optical or conductometric sensors, quartz crystal microbalance and cantilever [1][2][3][4][5][6][7][8]. The advent of nanostructured materials has created many opportunities to dramatically enhance the ability to detect adsorbed chemicals.…”