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Title: Development of nanosecond time-resolved infrared detection at the LEAF pulse radiolysis facility

When coupled with transient absorption spectroscopy, pulse radiolysis, which utilizes high-energy electron pulses from an accelerator, is a powerful tool for investigating the kinetics and thermodynamics of a wide range of radiation-induced redox and electron transfer processes. The majority of these investigations detect transient species in the UV, visible, or near-IR spectral regions. Unfortunately, the often-broad and featureless absorption bands in these regions can make the definitive identification of intermediates difficult. Time-resolved vibrational spectroscopy would offer much improved structural characterization, but has received only limited application in pulse radiolysis. In this paper, we describe in detail the development of a unique nanosecond time-resolved infrared (TRIR) detection capability for condensed-phase pulse radiolysis on a new beam line at the LEAF facility of Brookhaven National Laboratory. The system makes use of a suite of high-power, continuous wave external-cavity quantum cascade lasers as the IR probe source, with coverage from 2330 to 1051 cm{sup −1}. The response time of the TRIR detection setup is ∼40 ns, with a typical sensitivity of ∼100 μOD after 4-8 signal averages using a dual-beam probe/reference normalization detection scheme. This new detection method has enabled mechanistic investigations of a range of radiation-induced chemical processes, some of which aremore » highlighted here.« less
Authors:
; ; ; ;  [1] ;  [2]
  1. Chemistry Department, Brookhaven National Laboratory, P.O. Box 5000, Upton, New York 11973-5000 (United States)
  2. Department of Mathematics and Computer Science, Dowling College, 1300 William Floyd Parkway, Shirley, New York 11967 (United States)
Publication Date:
OSTI Identifier:
22392463
Resource Type:
Journal Article
Resource Relation:
Journal Name: Review of Scientific Instruments; Journal Volume: 86; Journal Issue: 4; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY; ABSORPTION; ABSORPTION SPECTROSCOPY; BEAMS; DETECTION; ELECTRON TRANSFER; KINETICS; LASERS; PROBES; PULSES; RADIOLYSIS; REACTION INTERMEDIATES; SENSITIVITY; TIME RESOLUTION