title: Fast neutrons produced by nuclear fragmentation in treatment irradiations with 12C beam.
abstract: In the framework of the heavy-ion tumour therapy project at GSI we investigated the nuclear fragmentation of 200 AMeV carbon ions stopping in a 12.78-cm thick water absorber. Fast neutrons and charged particles emerging from the target were registered at forward angles between 0 degrees and 30 degrees with a DeltaE-E-telescope consisting of an NE102 and a BaF2 scintillator. We obtained neutron energy spectra and angular distributions and derived the neutron yield in the energy range from 10 to 500 MeV in the forward hemisphere. In addition, we performed fragmentation measurements in actual patient treatment irradiations. The resulting angular distributions of neutrons and charged particles as well as their yields are similar to those obtained with the water absorber.
authors.affiliation: Gesellschaft für Schwerionenforschung, Planckstrasse 1, D-64291 Darmstadt, Germany. K.Gunzert@gsi.de
authors.forename: Konstanze
authors.initials: K
authors.lastname: Gunzert-Marx
authors.forename: Dieter
authors.initials: D
authors.lastname: Schardt
authors.forename: Reinhard S
authors.initials: RS
authors.lastname: Simon
mesh_terms: D001822:Body Burden; D002244:Carbon / Q000032:analysis* / Q000627:therapeutic use*; D005214:Fast Neutrons / Q000627:therapeutic use*; D006801:Humans; D017247:Neutron Capture Therapy / Q000379:methods*; D011835:Radiation Protection / Q000379:methods*; D011874:Radiometry / Q000295:instrumentation / Q000379:methods*; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods*; D012062:Relative Biological Effectiveness; D018570:Risk Assessment / Q000379:methods; D012680:Sensitivity and Specificity
chemical_list: D002244:Carbon