http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Prompt gamma detection for range verification in proton therapy
Shunsuke Kurosawa,Hidetoshi Kubo,Kazuki Ueno,Shigeto Kabuki,Satoru Iwaki,Michiaki Takahashi,Kojiro Taniue,Naoki Higashi,Kentaro Miuchi,Toru Tanimori,김도균,김종원 한국물리학회 2012 Current Applied Physics Vol.12 No.2
It is an on-going challenge to verify the proton range in situ during proton therapy. Since the protons stop in target tissue, measurement of gamma-rays emitted either promptly from nuclear de-excitation or in pair from positron annihilation is the feasible method to monitor the proton range in-vivo. Using the technique of gamma collimation, we empirically demonstrated that the proton range and prompt gamma distribution are well correlated in the therapy energy range, and that measuring prompt gammas is a viable method for the clinical application. However, this collimation technique appears not to be applicable to passively scattered proton beams. The device chosen for gamma imaging in 2D is an electron tracking Compton camera, which images single-emission photons employing a gas chamber to induce Compton scattering. Images of prompt gammas were attained at the proton beam energy of 140 MeV. Measurements showed that gamma image in the energy range of 800e2000 keV provides a better match with the proton range compared to the image by lower energy gammas.
Pejchal, Jan,Babin, Vladimir,Beitlerova, Alena,Kucerkova, Romana,Panek, Dalibor,Barta, Jan,Cuba, Vaclav,Yamaji, Akihiro,Kurosawa, Shunsuke,Mihokova, Eva,Ito, Akihiko,Goto, Takashi,Nikl, Martin,Yoshika Elsevier 2016 Optical Materials Vol.53 No.-
<P><B>Abstract</B></P> <P>Ce-doped lutetium aluminum garnet Lu<SUB>3</SUB>Al<SUB>5</SUB>O<SUB>12</SUB> (LuAG) nanoceramics were fabricated at 1600°C and 1700°C by spark-plasma sintering (SPS) method from nano-powders prepared by radiation synthesis. Both undoped and Ce-doped LuAG ceramic samples were also prepared from the nano-powders at 1700°C with significantly increased pre-heating rate. The backscattered electron images revealed large amount of pores in all the Ce-doped samples causing their significant opacity. On the other hand, very large grains and no pores were revealed in the undoped sample, which was the only transparent one. The radioluminescence measurements revealed superior overall scintillation efficiency of the samples sintered at the temperature 1700°C, and their defect emission in the UV region was ascribed to oxygen-vacancy-related defects such as F<SUP>+</SUP> centers. The photoluminescence decay of the defect emission was characterized by an extremely fast decay time of a few nanoseconds. Influence of sintering procedure and subsequent annealing on the luminescence and scintillation properties is discussed.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Ce-doped scintillation nanoceramics were prepared by a Spark-Plasma-Sintering method. </LI> <LI> High overall scintillation efficiency was found. </LI> <LI> For samples prepared with slower pre-heating, scintillation efficiency can be increased by annealing. </LI> <LI> Higher sintering temperatures and slower pre-heating stages positively influence scintillation efficiency. </LI> </UL> </P>