Program - Brookhaven National Laboratory

Impact of the Energy Dependent DDXS on Determination of Resonance Parameters
Ron Dagan, KIT-INR, Hermann von helmholtz Platz 76344 Egg. Leopoldshafen, Germany. Peter
Schillebeeckx, Bjoern Becker, Stefan Kopecky, EC-JRC-IRMM, Retieseweg 111, B-2440 Geel. Frank
Gunsing, Christos Lampoudis, CEA Saclay, Irfu, F - 91911 Gif-sur-Yvette, France France. Yaron Danon,
RPI, 110 8th St., Troy, NY 12180-3590. Mick Moxon, Hyde Copse 3, Marcham, United Kingdom.
This paper is sequential to former studies dealing with the impact of the resonant Double Differential
Cross Section-DDXS on core parameters and in particular on the line shape of resonance fitting with
which resonance parameters are being tested (or modified). The introduction of the Doppler Broadening
Rejection Correction - DBRC into Monte Carlo codes enabled a better insight of simulation of the multiple
scattering effect in Time of Flight - ToF measurements. Previous studies have shown that experimental
line shapes could be better fitted by introduction of a better DDXS model. Nevertheless, it was shown in
some cases that the quality of the models could be simplified as far as the complexity of the full DDXS
is concerned. Strictly speaking, on can get a better fitting by introduction only the correct temperature
without the energy dependency in the vicinity of the resonance or sometimes a higher multiple scattering
order (Y n , n=1..20), yet with the corrected asymptotic model (0 K) could suffice. This study extends the
above and is based on dedicated measurements to investigate in more detail the quality of the physical
model of the DDXS (temperature or/and resonance or/and solid state effect) and in return to analyse if
and how could the resonance parameters themselves be updated to get a better quality of specific resonant
nuclear data. In contrary to further measurements we focus in this work mainly on the resonance wings
via a combined self indication measurement and a DBRC based MC simulation. Examples based on
measurements of 197 Au and 238 U will be given.
LF 4 4:40 PM
The LENOS Project at Laboratori Nazionali di Legnaro of INFN-LNL
P. Mastinu, J. Praena, G. Martin-Hernández, N. Dzysiuk,
INFN, Laboratori Nazionali di Legnaro, Italy, Universidad de Sevilla, CNA, Sevilla, Spain, Centro de
Aplicaciones Tecnologicas y Desarrollo Nuclear, La Habana, Cuba, International Nuclear Safety Center of
Ukraine, Kyiv, Ukraine
G. Prete, R. Capote, M. Pignatari, J. M. Quesada Molina, A. Ventura, F. Gramegna
INFN, Laboratori Nazionali di Legnaro, Italy, NAPC-Nuclear Data Section, International Atomic Energy
Agency, Vienna, Austria, Department of Physics, University of Basel, Switzerland Universidad de
Sevilla, CNA, Sevilla, Spain ENEA, Bologna and INFN Sezione di Bologna, INFN, Laboratori Nazionali
di Legnaro, Italy
LENOS (Legnaro NeutrOn Source) project at the Laboratori Nazionali di Legnaro of INFN (Italy) is
a neutron irradiation facility for nuclear astrophysics studies and validation of evaluated nuclear data
libraries. It is based on a high current low energy RFQ. The facility under construction will use the 5
MeV, 50 mA proton beam of RFQ under test at LNL to produce an unprecedented neutron flux, precisely
shaped to a Maxwell- Boltzmann energy distribution at variable temperature kT. A new method has been
proposed to obtain the desired neutron spectra at different stellar energies and a dedicated target, able to
sustain a very high specific power, has been developed. We will present the facility, the method used to
shape the neutron beam, the preliminary results of the high power test of the micro-channel water cooled
target and the preliminary results of the validation measurement. Waiting for LENOS facility, currently
we are carrying out measurements at existing low power electrostatic accelerators, using other degrees of
freedom available in order to shape accurately the proton beam to a desired distribution. An overview of
recent measurements together with the capability of using additional degrees of freedom to achieve more
accurate Maxwellian distributions at temperatures higher than 50 keV will be presented.
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