放医研医用重粒子加速器施設における放射化ビームラインの設計

概要

論文の詳細を見る
A design of radioactive beam line and the analysis of expected beam quality have been made. In the heavy ion cancer therapy, radioactive beam (positron emitter) can be used to verify the range of the charged particles in tissue, because the radioactive nuclei which are produced by the peripheral fragmentation of relativistic heavy ions, have a similar characteristics with the primary particles. For example, about 1 % of 20Ne will be converted into 19Ne (half life 17.4 S) in a 5cm thickness of beryllium target.19Ne are magnetically selected and purified from other fragments, then transported to the experimental area. To increase precision of the range measurement, the momentum spread of the 19Ne beam will be reduced to ±0.2 % by a wedge degrader. Around 50 % of the primary particles pass through the target, then are deflected by a super-conducting coil and wasted at a beam dump. Other unuseful particles are stopped at slits. The shielding of the neutrons produced at the target and slits are also discussed.
Japan Society of Medical Physicsの論文