Author: Kanai, T.
Paper Title Page
MOPB54 Development of the New Type MLIC with PMMA Plates and Graphite Electrodes 194
 
  • S. Iwata, C. Kobayashi, N.S. Shinozaki, A. Takubo
    AEC, Chiba, Japan
  • S. Fukuda
    NIRS, Chiba-shi, Japan
  • T. Kanai
    Gunma University, Heavy-Ion Medical Research Center, Maebashi-Gunma, Japan
 
  The MLIC (Multi-Layer Ionization Chamber) that has a lot of ionization chambers stacked in the depth direction is a useful detector for measuring the depth dose distribution (DDD). By using the MLIC, the measurement time and the amount of beam for dosimetry are drastically decreased. In HIMAC (Heavy-Ion Medical Accelerator in Chiba), the MLIC has been effectively used for QA (Quality Assurance) measurement of heavy-ion therapeutic beam since 2002. We are developing a new type MLIC that has electrodes made of graphite on the surface of the polymethyl-methacrylate (PMMA) plates for particle therapy. The purpose is to obtain the same results as the DDD in water. We will report on the progress of the development.  
 
MOPB58 Beam Quality Ensuring Instruments at the Gunma University Heavy-ion Medical Center 209
 
  • E. Takeshita, T. Kanai, M. Kawashima, Y. Kubota, A. Matsumura, A. Saito, H. Shimada, M. Tashiro, K. Torikai, S. Yamada, K. Yusa
    Gunma University, Heavy-Ion Medical Research Center, Maebashi-Gunma, Japan
 
  Since the carbon beam based cancer therapy started at the Gunma University Heavy-ion Medical Center in the year 2010, the total number of treated patients increased to 306 by the end of fiscal 2011. This year, already 82 patients have been treated. In order to control the medical beam qualities, i.e., position, size and intensity of the beam, monitoring devices were mounted on the high-energy beam transport line. The beam position and size can be measured and tuned with a screen monitor, which consists of a fluorescent screen and a CCD camera. Just before starting the treatment, the operators check for a proper beam position by strip-line monitor measurements placed close to the iso center. The irradiation dose is controlled using two secondary electron emission monitors placed before the wobbling magnets. This dose monitor is helpful for high fluence of the beam because it's less affected by the recombination effect. In the conference, we would like to report on details of each monitoring device.