000033601 001__ 33601
000033601 005__ 20180127185137.0
000033601 0247_ $$2doi$$a10.5075/epfl-thesis-3132
000033601 02470 $$2urn$$aurn:nbn:ch:bel-epfl-thesis3132-5
000033601 02471 $$2nebis$$a4809056
000033601 037__ $$aTHESIS_LIB 000033601 041__$$aeng
000033601 088__ $$a3132 000033601 245__$$aMeasurements and Monte Carlo calculations with the extended-range Bonner sphere spectrometer at high-energy mixed fields
000033601 269__ $$a2004 000033601 260__$$aLausanne$$bEPFL$$c2004
000033601 300__ $$a196 000033601 336__$$aTheses
000033601 502__ $$aAbbas Aroua, Aurélio Bay, Harald Brune, Marco Silari 000033601 520__$$aThe use of spectrometry to provide information for neutron radiation protection has become an increasingly important activity over recent years. The need for spectral data arises because neither area survey instruments nor personal dosimeters give the correct dose equivalent results at all neutron energies. It is important therefore to know the spectra of the fields in which these devices are used. One of the systems most commonly employed in neutron spectrometry and dosimetry is the Bonner Sphere Spectrometers (BSS). The extended-range BSS that was used for this work, consists of 7 spheres with an overall response to neutrons up to 2 GeV. A 3He detector is used as a thermal counter in the centre of each sphere. In the context of this thesis the BSS was calibrated in monoenergetic neutron fields at low and intermediate energies. It was also used for measurements in several high energy mixed fields. These measurements have led to the calculation of neutron yields and spectral fluences from unshielded targets. Such data are very useful for shielding calculations and other radiation protection measurements. Furthermore, an upgrade of the response of the BSS to charged hadrons was achieved. Among the fields were the BSS has been tested, the CERF facility is of particular interest. It is installed in one of the secondary beam lines from the Super Proton Synchrotron (SPS) in the French site of CERN. The particle composition and spectral fluences outside the shielding of CERF simulate those in the cosmic radiation field at commercial flight altitudes. In the last decade interest has arisen in CERF from research institutions working in the space programme. There is therefore a need for setting-up a new exposure area reproducing the radiation environment found outside the atmosphere or inside a space vessel. The results from Monte Carlo studies that have been carried out for this purpose show a good agreement with experimental data taken inside the MIR space station. Therefore, CERF may prove to be a very useful tool for further tests with the BSS system, towards its upgrade for measurements in cosmic ray fields.
000033601 700__ $$0(EPFLAUTH)161477$$aDimovasili, Evangelia$$g161477 000033601 720_2$$aValley, Jean-François$$edir. 000033601 8564_$$iINTERNAL$$uhttps://infoscience.epfl.ch/record/33601/files/EPFL_TH3132.pdf$$xRESTRICTED$$zTexte intégral / Full text 000033601 909CO$$ooai:infoscience.tind.io:33601$$pthesis-bn2018$$pthesis
000033601 918__ $$aSB$$bSB-SPH$$cIRA 000033601 920__$$a2004-12-9$$b2004 000033601 970__$$a3132/THESES
000033601 973__ $$aEPFL$$sPUBLISHED
000033601 980__ aTHESIS