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Journal ArticleDOI

Design and performance of a pulse radiolysis system capable of picosecond time resolution.

01 Mar 1970-Review of Scientific Instruments (American Institute of Physics)-Vol. 41, Iss: 3, pp 333-340
TL;DR: A unique stroboscopic pulse radiolysis system is described which detects the transient light‐absorbing species formed in solutions by individual fine structure pulses from a 40 MeV linear accelerator, and meets its expected performance capability.
Abstract: A unique stroboscopic pulse radiolysis system is described which detects the transient light‐absorbing species formed in solutions by individual fine structure pulses from a 40 MeV linear accelerator. A measured time resolution of 23 psec is attained by using, as the analyzing light, the short (<10 psec) Cerenkov light flashes produced in air by the fine structure pulses of the electron beam. This light is suitably delayed by an optical system in which the path length is slowly changed, then passed through the irradiated sample. The integrated light passing through the sample id detected, and variations in the optical absorption at varying times after the irradiation pulse are observed. The design and performance of the optical, mechanical, and electronic devices which retrieve the absorption signal out of the noise are described in some detail. As an integrated unit, this system meets its expected performance capability, being able to successfully detect absorption signals as small as 0.2%.
Citations
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Journal ArticleDOI
28 Feb 2011-Water
TL;DR: A brief history of the development of the understanding of water radiolysis is presented in this paper, with a focus on the H2 production, and different parameters accounting for this behavior are presented.
Abstract: The radiolysis of water due to ionizing radiation results in the production of electrons, H· atoms, ·OH radicals, H3O+ ions and molecules (dihydrogen H2 and hydrogen peroxide H2O2). A brief history of the development of the understanding of water radiolysis is presented, with a focus on the H2 production. This H2 production is strongly modified at oxide surfaces. Different parameters accounting for this behavior are presented.

432 citations


Cites background from "Design and performance of a pulse r..."

  • ...The time resolution was then lowered to the nanosecond [32] and then picosecond time scale [33-38]....

    [...]

Journal ArticleDOI
TL;DR: The BNL Laser-Electron Accelerator Facility (LEAF) uses a laser-pulsed photocathode, radio-frequency electron gun to generate pulses of 8.7 MeV electrons for pulse radiolysis experiments.
Abstract: The BNL Laser-Electron Accelerator Facility (LEAF) uses a laser-pulsed photocathode, radio-frequency electron gun to generate ⩾7 ps pulses of 8.7 MeV electrons for pulse radiolysis experiments. The compact and operationally simple accelerator system includes synchronized laser pulses that can be used to probe or excite the electron-pulsed samples to examine the dynamics and reactivity of chemical species on the picosecond time scale.

130 citations

Journal ArticleDOI
TL;DR: In this article, the decay of solvated electrons in various aqueous solutions was studied using a stroboscopic pulse radiolysis technique with a time resolution of 24 psec.
Abstract: The decay of solvated electrons in various aqueous solutions was studied using a stroboscopic pulse radiolysis technique with a time resolution of 24 psec. High concentrations of solutes such as H2O2, acetone, CdCl2, NaNO2, and NaNO3 decreased the initial solvated electron yield, while high acid concentrations did not. Reasons for this reduction in yield are discussed, and the conclusion reached is that the scavengers must be reacting with a precursor to the solvated electron. We believe that this precursor is probably a low‐energy electron which reacts prior to solvation.

126 citations

Journal ArticleDOI
TL;DR: In this paper, the initial yield of solvated electrons in all solvents studied was reduced in the presence of a high concentration of scavengers, and exhibited a semilogarithmic dependence on the scavenger concentration.

99 citations

Journal ArticleDOI
TL;DR: In this article, the authors describe the construction and commissioning of ELYSE, the first machine of this type in Europe, which is a 4-9-MeV electron accelerator using RF gun technology.
Abstract: Recent years have seen an increasing interest in the use of intense, short pulse electron beams for pulsed radiolysis research. Laser driven photo-cathodes inserted in radio frequency (RF) guns are ideal candidates to provide electron beams for time-resolved spectroscopic observation of very fast chemical reactions. These guns have been developed through accelerator R&D programmes in the field of high brightness sources for other applications (linear colliders, free electron lasers). The Physical Chemistry Laboratory at the University of Paris-Sud has created a Fast Kinetics Centre for experimental pulse radiolysis with picosecond time resolution. At the heart of this new facility is a compact 4–9 MeV electron accelerator, ELYSE, using RF gun technology. It has been designed and built by the Linear Acclerator Laboratory at the University of Paris-Sud. We will describe the construction and commissioning of ELYSE, the first machine of this type in Europe.

95 citations

References
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Journal ArticleDOI
TL;DR: In this paper, a brief review of the original discovery of the radiation and the physical principles of the process that gives rise to it is given, followed by an elementary account of the theory of the effect.
Abstract: The paper opens with a brief review of the original discovery of the radiation and the physical principles of the process that gives rise to it. This is followed by an elementary account of the theory of the effect. A general survey of the practical applications to cosmic-ray and high-energy physics is then presented, with two examples of modern detectors discussed in greater detail. The article concludes with an account of recent experiments carried out on light pulses from the night-sky associated with cosmic-ray showers, found to be due to Cerenkov radiation in the atmosphere.

678 citations

Book
01 Jan 1958
TL;DR: In this paper, a brief review of the original discovery of the radiation and the physical principles of the process that gives rise to it is given, followed by an elementary account of the theory of the effect.
Abstract: The paper opens with a brief review of the original discovery of the radiation and the physical principles of the process that gives rise to it. This is followed by an elementary account of the theory of the effect. A general survey of the practical applications to cosmic-ray and high-energy physics is then presented, with two examples of modern detectors discussed in greater detail. The article concludes with an account of recent experiments carried out on light pulses from the night-sky associated with cosmic-ray showers, found to be due to Cerenkov radiation in the atmosphere.

581 citations

Journal ArticleDOI
TL;DR: In this article, an optical system, in conjunction with a light source, a photodetector and a cathode-ray oscilloscope, is used to investigate the time variation in concentration of optically absorbing chemical species produced by the radiation.
Abstract: Apparatus for investigating the kinetics of radiation induced chemical reactions is described. It is used with a 4 Mev linear electron accelerator which is arranged to give any dose from a few tens of rads up to about 10 kilorads, to a small liquid sample in a single pulse lasting either 2.0 or 0.2 μsec. An optical system, in conjunction with a light source, a photodetector and a cathode-ray oscilloscope, is used to investigate the time variation in concentration of optically absorbing chemical species produced by the radiation. The importance of proper design of the optical system, if maximum sensitivity is required, is stressed. Shot noise in the photodetector is a natural limitation to the sensitivity of the method, when measurements are made in the microsecond region, and it is therefore necessary to get as much light as possible through the irradiation cell.

219 citations

Journal ArticleDOI
TL;DR: The design and testing of a pulse radiolysis system with a resolving time of 2.5 nsec is described, using a 1P28 photomultiplier tube directly coupled to a sampling oscilloscope in conjunction with a 3-nsec 1.5-amp electron pulse from a3-MeV Van de Graaff generator.
Abstract: The design and testing of a pulse radiolysis system with a resolving time of 2.5 nsec is described. This system utilized a 1P28 photomultiplier tube directly coupled to a sampling oscilloscope to attain a rise time of 2.5 nsec. Random shot noise was kept small by using an intense xenon light source, and photomultiplier fatigue was reduced by means of a rotating sector which reduced the average light intensity by 72 times. This system was used in conjunction with a 3-nsec 1.5-amp electron pulse from a 3-MeV Van de Graaff generator. The formation and decay of the solvated electron in water were critically examined. There was no evidence that a delay of greater than 0.5 nsec in the formation of $e_{{\rm aq}}^{-}$ , or that a significant fraction of the solvated electrons showed a nonhomogeneous "spur" type of decay in times longer than 0.5 nsec.

65 citations