Design of the 50 kW Neutron Converter for SPIRAL2 Facility
Nuclear Instruments and Methods in Physics Research Section A
||Neutron sources, Nuclear reaction, Radioactive ion beams
Budker Institute of Nuclear Physics SB RAS
Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Legnaro
Boreskov Institute of Catalysis SB RAS
Trofimuk Institute of Petroleum Geology and Geophysics Sibirian Branch of the Russian Academy of Sciences
212692 FP7-INFRASTRUCTURES-2007-1 SPIRAL2PP
International Science and Technology Center
SPIRAL2 is a facility for the study of fundamental nuclear physics and multidisciplinary research.
SPIRAL2 represents a major advance for research on exotic nuclei. The radioactive ion beam (RIB)
production system is comprised of a neutron converter, a target and an ion source. This paper is
dedicated to the designing of the 50 kW neutron converter for the SPIRAL2 facility.
Among the different variants of the neutron converter, the one based on a rotating solid disk seems
quite attractive due to its safety, ease in production and relatively low cost. Dense graphite used as
the converter’s material allows the production of high-intensity neutron flux and, at the same time, the
heat removal from the converter by means of radiation cooling.
Thermo-mechanical simulations performed in order to determine the basic geometry and physical
characteristics of the neutron production target for SPIRAL2 facility, to define the appropriate beam
power distribution, and to predict the target behaviour under the deuteron beam of nominal
parameters (40 MeV, 1.2 mA, 50 kW) are presented.
To study the main physical and mechanical properties and serviceability under operating conditions,
several kinds of graphite have been analyzed and tested. The paper reports the results of such
Radiation damage is the most important issue for the application of graphite as neutron converter. It
is well known that the thermal conductivity of the neutron-irradiated graphite is reduced by a factor of
10 from the initial value after irradiation. Difference in volume expansions between the matrix and the
fiber results in serious damage of neutron-irradiated C/C composites. Calculations showed that at high
temperature the effect of neutron radiation is not so critical and that the change in thermal conductivity
does not prevent the use of graphite as neutron converter.