title: Compensation for beam intensity fluctuation in determination of P(ion) the ion-recombination correction factor for ionization chambers, by the two-voltage technique.
abstract: We have developed a method of compensation for fluctuations in beam intensity that may occur during measurement of Pion, the ion-recombination correction factor, by the two-voltage technique. The method requires signals proportional to beam intensity during measurement. We used a parallel-plate ionization chamber, whose Pion was known, and a vacuum chamber to obtain signals that were proportional to the beam intensity. Experiments were conducted using pulsed proton beam providing doses that ranged from 0.16 to 0.01 cGy/pulse. The value of Pion of a thimble ionization chamber was measured. With these measurements, the validity of the method which we proposed for pulsed beam was verified experimentally.
authors.affiliation: Institute of Basic Medical Sciences, University of Tsukuba, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Hayakawa
authors.forename: C P
authors.initials: CP
authors.lastname: Loch
authors.forename: J
authors.initials: J
authors.lastname: Tada
authors.forename: T
authors.initials: T
authors.lastname: Inada
mesh_terms: D010315:Particle Accelerators; D011522:Protons; D011874:Radiometry / Q000295:instrumentation* / Q000379:methods; D011882:Radiotherapy, High-Energy; D012984:Software
chemical_list: D011522:Protons