@article{oai:repo.qst.go.jp:00045220,
 author = {Sakama, Makoto and Kanai, Tatsuaki and Fukumura, Akifumi and 坂間 誠 and 金井 達明 and 福村 明史},
 issue = {1},
 journal = {Japanese Journal of Medical Physics},
 month = {May},
 note = {Abstract 
We developed and performance-tested a portable graphite calorimeter designed to measure the absolute 
dosimetry of various beams including heavy-ion beams, using a flexible and convenient means of measurement. 
This measurement system is fully remote-controlled by GPIB systems. The control system uses digital PID 
(Proportional, Integral, Derivative) control methods based on a LabVIEW program1). It was possible to attain 
stable conditions in a shorter time by this system. The standard deviation of the measurements using the 
calorimeter was 0.79 % at a dose rate of 0.8 Gy/min in seventeen calorimeter runs of a 60Co photon beam. The 
overall uncertainty for the absorbed dose to graphite and water of a 60Co photon beam using the developed 
calorimeter was 0.89 % and 1.35 %, respectively. Estimations of the correction factors due to vacuum gaps, 
impurities in the core, the dose gradient and the radiation profile were included in the uncertainty. The 
absorbed doses to graphite and water irradiated by a 60Co photon beam were compared with dosimetry using 
ionization chambers. The absorbed doses to graphite and water estimated by the two dosimetry methods agreed 
within 0.1 % and 0.3 %, respectively.},
 pages = {1--14},
 title = {Development of a Portable Graphite Calorimeter for Radiation Dosimetry},
 volume = {28},
 year = {2008}
}