scispace - formally typeset
Search or ask a question
Author

B. Tamain

Bio: B. Tamain is an academic researcher from Centre national de la recherche scientifique. The author has contributed to research in topics: Nucleon & Charged particle. The author has an hindex of 34, co-authored 113 publications receiving 2904 citations.


Papers
More filters
Journal ArticleDOI
04 Nov 2001
TL;DR: In this paper, the authors describe the development and testing of a low-cost radiotherapy dosimeter (SDM) based on scintillating fibers and signal processing to reduce the effect of Cerenkov radiation background.
Abstract: Radiation therapy accelerators require highly accurate dose deposition and the output must be monitored frequently and regularly. Ionization chambers are the primary tool for this control, but their size and fragility make them unsuitable for use during patient treatment. In collaboration with a French center for cancer treatment in Caen, we describe the development and testing of a low-cost radiotherapy dosimeter (SDM) based on scintillating fibers and signal processing to reduce the effect of Cerenkov radiation background. The employment of photodiodes for light collection reduces the cost relative to systems using photomultipliers (PMTs). However, we have also developed a highly sensitive system that uses PMTs for very low-dose deposition for Brachytherapy. Comparison with standard ionization chambers shows about a 1% difference over a range of 6- to 25-MV photons. This dosimeter is 1 mm in diameter and can be placed where ever required including inside the body. Its small size and flexibility make it useful for delimiting critical regions, where organs may be very radiation sensitive.

189 citations

Journal ArticleDOI
TL;DR: In this paper, the authors used the transverse energy of light particles as an impact parameter selector and compared the results with dynamical models with which a good agreement was obtained. But the results were not compared to dynamical model with which good agreement is obtained.
Abstract: Experimental data obtained with the 4{pi} multidetector system INDRA are used to study the light charged particle (LCP, Z{le}2) and intermediate mass fragment (IMF, Z{ge}3) production in peripheral and semicentral collisions of Xe and Sn at 50 MeV/nucleon. It is found that a sizable fraction of the detected LCP`s and IMF`s originates from the midvelocity region. These fragments can be seen to come either from a prompt (preequilibrium) mechanism or from a slower but dynamically influenced emission process. The relative magnitude of the dynamically influenced emission relative to the isotropic statistical evaporation is presented as a function of the transverse energy of light particles, used as an impact parameter selector. The results are compared to dynamical models with which a good agreement is obtained. {copyright} {ital 1997} {ital The American Physical Society}

90 citations

Journal ArticleDOI
TL;DR: In this paper, the INDRA multidetector was used to study multifragmentation processes in central collisions for the Xe + Sn reaction at 50 A MeV, and the fragment kinetic energy spectra indicated a fast disintegration of the system with a radial collective motion of about 2 A MEV.

86 citations

Journal ArticleDOI
TL;DR: In this article, the relative weight of the interaction channel C-12(n,n'gamma) in the organic liquid scintillator was determined experimentally, taking into account observed saturation effects in the detector output, a calibration method was proposed for high light outputs, based on the energy loss of cosmic ray muons.
Abstract: DEMON is a detector array for neutrons emitted in heavy ion induced reactions at low to intermediate energies. The neutron detection efficiency of some single DEMON modules has been measured in the energy range 8-21 MeV, with detection thresholds down to 0.1 MeV equivalent-electron (MeVee). The influence on the efficiency of cross talk, neutron-gamma and neutron-charged particle discrimination techniques was found to be negligibly small. Monte Carlo simulations have been performed and are compared with the experimental data. The relative weight of the interaction channel C-12(n,n'gamma) in the organic liquid scintillator was determined experimentally. Taking into account observed saturation effects in the detector output, a calibration method is proposed for high light outputs, based on the energy loss of cosmic ray muons.

86 citations

Journal ArticleDOI
TL;DR: In this paper, the mass distribution of the fission fragments has been measured and it has been found that their width strongly increases with angular momentum especially when the Fission barrier has vanished.

85 citations


Cited by
More filters
Journal ArticleDOI
01 Apr 1988-Nature
TL;DR: In this paper, a sedimentological core and petrographic characterisation of samples from eleven boreholes from the Lower Carboniferous of Bowland Basin (Northwest England) is presented.
Abstract: Deposits of clastic carbonate-dominated (calciclastic) sedimentary slope systems in the rock record have been identified mostly as linearly-consistent carbonate apron deposits, even though most ancient clastic carbonate slope deposits fit the submarine fan systems better. Calciclastic submarine fans are consequently rarely described and are poorly understood. Subsequently, very little is known especially in mud-dominated calciclastic submarine fan systems. Presented in this study are a sedimentological core and petrographic characterisation of samples from eleven boreholes from the Lower Carboniferous of Bowland Basin (Northwest England) that reveals a >250 m thick calciturbidite complex deposited in a calciclastic submarine fan setting. Seven facies are recognised from core and thin section characterisation and are grouped into three carbonate turbidite sequences. They include: 1) Calciturbidites, comprising mostly of highto low-density, wavy-laminated bioclast-rich facies; 2) low-density densite mudstones which are characterised by planar laminated and unlaminated muddominated facies; and 3) Calcidebrites which are muddy or hyper-concentrated debrisflow deposits occurring as poorly-sorted, chaotic, mud-supported floatstones. These

9,929 citations

Journal ArticleDOI
TL;DR: In this paper, the authors review the major progress achieved during the last decade in isospin physics with heavy ion reactions and discuss future challenges to the most important issues in this field.

940 citations

Journal ArticleDOI
TL;DR: In this article, the authors focus on the possibilities of detecting the various subtypes of (excited) BSs: possible signals include gravitational redshift and (micro-)lensing, emission of gravitational waves, or, in the case of a giant BS, its dark matter contribution to the rotation curves of galactic halos.
Abstract: There is accumulating evidence that (fundamental) scalar fields may exist in nature. The gravitational collapse of such a boson cloud would lead to a boson star (BS) as a new type of a compact object. As with white dwarfs and neutron stars, a limiting mass exists similarly, below which a BS is stable against complete gravitational collapse to a black hole. According to the form of the self-interaction of the basic constituents and spacetime symmetry, we can distinguish mini-, axidilaton, soliton, charged, oscillating and rotating BSs. Their compactness prevents a Newtonian approximation; however, modifications of general relativity, as in the case of Jordan?Brans?Dicke theory as a low-energy limit of strings, would provide them with gravitational memory. In general, a BS is a compact, completely regular configuration with structured layers due to the anisotropy of scalar matter, an exponentially decreasing 'halo', a critical mass inversely proportional to the constituent mass, an effective radius and a large particle number. Due to the Heisenberg principle, a completely stable branch exists, and as a coherent state, it allows for rotating solutions with quantized angular momentum. In this review, we concentrate on the fascinating possibilities of detecting the various subtypes of (excited) BSs: possible signals include gravitational redshift and (micro-)lensing, emission of gravitational waves, or, in the case of a giant BS, its dark matter contribution to the rotation curves of galactic halos.

628 citations

Journal ArticleDOI
TL;DR: In this paper, the results of ab initio simulations of n -rich, n -poor, heavy-ion collisions, using stochastic isospin-dependent transport equations, are analyzed as a function of beam energy and centrality.

534 citations

Journal ArticleDOI
TL;DR: In this paper, the Boltzmann Langevin Equation (BLE) is used to describe the dynamics of nuclear particle de-excitation by thermal fission in the presence of particle evaporation.

322 citations