CERN Accelerating science

Preprint
Report number	E1-2004-79 ; JINR-E1-2004-79
Title	Investigation of Neutron Spectra and Transmutation of ^{129}I, ^{237}Np and Other Nuclides with 1.5 GeV Protons from the Dubna Nuclotron Using the Electronuclear Setup "Energy plus Transmutation"
Author(s)	Krivopustov, M I ; Adam, J ; Balabekyan, A R ; Batusov, Yu A ; Bielewicz, M ; Brandt, R ; Chaloun, P ; Chultem, D ; Dwivedi, K K ; Elishev, A F ; Fragopoulou, M ; Henzl, V ; Henzlová, D ; Kalinnikov, V G ; Kievets, M K ; Krása, A ; Krizek, F ; Kugler, A ; Manolopoulou, Metaxia ; Mariin, I I ; Nourreddine, A ; Odoj, R ; Pavliouk, A V ; Pronskikh, V S ; Robotham, H ; Siemon, K ; Szuta, M ; Stegailov, V I ; Solnyshkin, A A ; Sosnin, A N ; Stoulos, S ; Tsoupko-Sitnikov, V M ; Tumendelger, T ; Wojecehowski, A ; Wagner, V ; Wan, J S ; Westmeier, W ; Zamani-Valasiadou, M ; Kumawat, H ; Kumar, V ; Zaverioukha, O S ; Zhuk, I V
Affiliation	(Veksler and Baldin Laboratory of High Energies, Dubna) ; (Nuclear Physics Institute of CAS, 250 68 \v{R}e\v{z}, Czech Republic) ; (Institute of Atomic Energy, 05-400 Otwock-Swierk, Poland) ; (Fachbereich Chemie, Philipps-Universitat, 35032 Marburg, Germany) ; (Arunachal University, Rono Hills, 791 111 Itanagar, India) ; (Physics Department, Aristotle University, Thessaloniki, Greece) ; (Joint Institute of Power and Nuclear Research, NASB, Sosny, 220109 Minsk, Belarus) ; (Institut de Recherche Subatomique, Louis Pasteur University, F-67037 Strasbourg, France) ; (Institut fuer Sicherheitsforschung und Reaktortechnik, FZJ, 52425 Juelich, Germany) ; (Northwest Institute of Nuclear Technology, Xian, China) ; (HENP Laboratory, University of Rajasthan, Jaipur, India)
Publication	2004
Imprint	23 Jun 2004
Number of pages	33
Published in:	Nucl. Instrum. Methods Phys. Res., A
Presented at	17th International Baldin Seminar on High Energy Physics Problems: Relativistic Nuclear Physics and Quantum Chromodynamics
Subject category	Particle Physics - Experiment
Abstract	Experiments which are part of the scientific program "Investigations of physical aspects of electronuclear method of energy production and transmutation for radioactive waste of atomic energetics using relativistic beams from the JINR Synchrophasotron/Nuclotron" (project "Energy plus Transmutation") are described. A large lead target surrounded by a four-section uranium blanket with total weight of 206.4 kg natural uranium was irradiated with 1.5 GeV protons from the new cryogenic accelerator Nuclotron. Radiochemical sensors were exposed to the secondary particle fluences inside and on top of the target assembly. Two long-lived radioactive waste of atomic energetics sensors ^{129}I and ^{237}Np (approximately 1 g weight each) and stable nuclides ^{27}Al, ^{59}Co, ^{127}I, ^{139}La, ^{197}Au and ^{209}Bi as well as natural and enriched uranium were used. In addition, various solid state nuclear track detectors and nuclear emulsions were exposed simultaneously. The experimental results confirm the theoretical estimations that the neutron spectra around the U/Pb-assembly are dominated by medium- and high-energy neutrons as shown by the observation of (n,xn)-reaction products in Co, Au and Bi sensors. The yield of thermal neutrons on the surface of the U-blanket is strongly reduced as compared to the surface of a smaller Pb target surrounded with paraffin. The latter data were determined with (n,\gamma) reactions in stable La sensors. In this experiment the technique of nuclear emulsions has been applied for the first time to measurements of neutron spectra in an accelerator driven system.
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