JAEA-Conf 2011-002 - 日本原子力研究開発機構

JAEA-Conf 2011-002
forward angles. The measured DDXs were compared with the calculated ones by PHITS code.
2. Experimental set up
The experiments were carried out at the heavy ion accelerator facility HIMAC (Heavy Ion
Medical Accelerator in Chiba) of the National Institute of Radiological Sciences in Japan. Fig.
1 shows the experimental setup. Oxygen beams were accelerated by a ring synchrotron up to
290 MeV/u and bombarded the targets. The thicknesses of carbon, aluminium and copper
targets were 4 mm. A thin plastic scintillator (beam monitor) was placed upstream of the
target in order to measure the number of incident oxygen ions. The size of the plastic
scintillator was 1 mm thick and 150 mm × 150 mm square. The active collimator is a plastic
scintillator of 10 mm thick and 40 mm × 40 mm square with a circular aperture of 15 mm in
diameter at the centre. The diameter of the aperture defined the solid angle of the
measurement.
Fig.1. Schematic experimental arrangement
The deuterons emitted from the nuclear reactions in the targets were detected by stacked
scintillator spectrometer placed at 5, 10 and 15 degrees relative to the beam line. The flight
path between the target and detectors was 600 mm at 5 degrees, and it was 325 mm at 10 and
15 degrees.
Fig. 2 shows the configuration of the spectrometer. The spectrometer were in principle a
ΔE-E counter telescope consisting of a plastic scintillator, four cubic GSO(Ce) crystals and a
cylindrical GSO(Ce) crystal. The plastic scintillator was 10 mm thick and served as ΔE
detector. The cubic crystals had 43 mm edge length. The cylindrical crystal was 60 mm in
diameter and 120 mm in length. Photomultiplier tubes (PMTs) viewed one faces of the plastic
scintillator and GSO(Ce) crystals.