Program - Brookhaven National Laboratory

were chemically separated and the 227 Ac was quantified using alpha spectroscopy. These results, along with
previously published data and theoretical values, outline accelerator production pathways for 227 Ac, which
can be used as a 223 Ra generator, and for 225 Ac with a minimized level of 227 Ac impurity.
HB 3 4:20 PM
Cross Sections for Proton Induced Reactions on Thorium at 800 MeV
J. W. Engle, J. Weidner, S. G. Mashnik, B. D. Ballard, M. E. Fassbender, L. J. Bitteker, A. Couture, J.
L. Ullmann, K. D. John, E. R. Birnbaum, F. M. Nortier
Los Alamos National Laboratory, Los Alamos, NM 87545, USA
Cross sections were measured for the formation of 69 nuclei from natural thorium targets irradiated with 800
MeV protons in the Blue Room of the Los Alamos National Laboratory (LANL) Neutron Science Center.
Irradiated thorium foils were assayed by gamma spectroscopy to quantify produced radionuclides. The
formation of non-actinide isotopes by fission and spallation processes during irradiations of thick thorium
targets is germane to the development of radiochemical separations and routine irradiation procedures
necessary to produce 225 Ac for use in clinical trials. Predictions by the recent LANL Monte Carlo MCNP6
transport code using different models considered by its several event generators are compared with measured
data in order to Verify and Validate (V&V) MCNP6.
HB 4 4:40 PM
Nuclear Fragmentation Measurements for Hadrontherapy: 95MeV/u 12 C Reactions on H,
C, Al, O and nat Ti Targets
J. Dudouet, M. Labalme, J.C. Angelique, J. Colin, D. Cussol, J.M. Fontbonne., LPC Caen, ENSICAEN,
Université de Caen, CNRS/IN2P3, Caen, France. D. Juliani, C. Finck, M. Rousseau., IPHC Strasbourg,
Université Louis Pasteur, CNRS/IN2P3, Strasbourg, France. P. Henriquet, J. Krimmer., IPN-Lyon,
Université de Lyon, Université Lyon 1, CNRS/IN2P3, Villeurbanne, France. B. Braunn, CEA Saclay,
DSM/IRFU/SPhN, Gif sur Yvette, France. M.G. Saint-Laurent, GANIL, CEA/DSM-CNRS/IN2P3,
Caen, France.
The interest for hadrontherapy, the use of ion beams for the treatments of cancerous tumors, is increasing.
This can be attributed to the great accuracy of ion beams to target the tumor while sparing the surrounding
healthy tissues (due to the high dose deposition in the Bragg peak and the small angular scattering
of ions) as well as the potential biological advantage of ions for some tumor types compared to photons.
To keep the benefits of carbon ions in radiotherapy, a very high accuracy on the dose location is required.
The dose deposition is affected by the fragmentation of the incident ion that leads to a consumption of
the projectiles with their penetration depth in the tissues (up to 70% for 400MeV/u 12 C in water), to the
creation of lighter fragments having different biological effectiveness (RBE) and to the apparition of a fragmentation
tail behind the tumor. The constraints on nuclear models and fragmentation cross sections in
the energy range used in hadrontherapy (80 to 400MeV/u) are not yet sufficient to reproduce the fragmentation
processes with the required accuracy for clinical treatments. A first integral experiment, on thick
water equivalent targets has been performed by our collaboration on May 2008 at GANIL (France) [1]. The
goals were the measurements of energy and angular distributions of the fragments due to nuclear reactions
of 95MeV/u 12 C with thick PMMA targets. Comparisons between experimental data and Geant4 simulations
using different physics processes show discrepancies up to one order of magnitude for the production
rates of fragments. The shapes of the angular and energy distributions are also not well reproduced. To
110