Program - Brookhaven National Laboratory

GF 4 2:40 PM
The Limits of the GAINS Spectrometer
A. Negret, C. Borcea
IFIN-HH, Bucharest ROMANIA
A.J.M. Plompen, C. Rouki, N. Nankov
EC-JRC-IRMM, Geel, BELGIUM
The Gamma Array for Neutron Inelastic Scattering (GAINS) [1] is currently operating at the GELINA
neutron source producing highly precise neutron data. The setup was used during the last years to
determine the neutron inelastic cross sections on 28 Si, 24 Mg, 23 Na, 90 Zr and other isotopes of importance
for the development of the next generation of nuclear reactors. Some of these data are still under analysis
while other were already published [2,3]. More recently we performed several experiments pushing the
technical capabilities of the experimental setup to the limits. We will present the preliminary results
obtained for 12 C and 57 Fe. The first case is the lightest nucleus ever studied with the present setup.
We aimed the determination of the cross section for the 4438 keV gamma ray produced in the inelastic
excitation of 12 C using large volume HPGe detectors. On the contrary, in case of the 57 Fe isotope, the
measurement attempted the determination of a gamma ray of the energy as small as 14 keV using the
same array of detectors. The second part of the presentation will focus on the recent development of an
analysis technique meant to produce covariance matrices for the inelastic cross section data from GAINS.
During this effort we also explore the uncertainty limits and the technical capabilities of the setup. We
will show the main steps of our analysis technique together with the first covariance matrices produced for
the test case of 28 Si.
[1] D. Deleanu, C. Borcea, Ph. Dessagne, M. Kerveno, A. Negret, A.J.M. Plompen and J.C. Thiry, Nucl.
Instrum. and Meth. in Phys. Res. A624, 130 (2010) [2] A. Negret, C. Borcea and A.J.M. Plompen, J.
Korean Phys. Soc. 59, 1765 (2011) [3] C. Rouki, P. Archier, C. Borcea, et al., Nucl. Instrum. and Meth.
in Phys. Res. A672, 82 (2012)
Session HA Neutron Cross Section Measurements
Tuesday March 5, 2013
Room: Met East at 3:30 PM
HA 1 3:30 PM
The CERN n TOF facility: Neutron Beams Performances for Cross Section Measurements
E. Chiaveri, on behalf of the n TOF Collaboration
CERN
The existing CERN n TOF neutron beam is characterized by a very high instantaneous neutron flux,
excellent TOF resolution at the 185 m long flight path, low intrinsic backgrounds and coverage of a wide
range of neutron energies, from thermal to a few GeV. These characteristics provide a unique possibility
to perform neutron-induced cross-section and angular distribution measurements for applications such as
nuclear astrophysics, nuclear reactor technology and basic nuclear physics. This paper presents in detail all
the characteristics of the present neutron beam in the different available configurations, which correspond
to two different collimation systems and two choices of neutron moderator. The features include shape
and intensity of the neutron flux, beam spatial profile, in-beam background components and the energy
resolution broadening. The description of these features is based upon both dedicated measurements as well
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