EBT2 dosimetry of x-rays produced by the electron beam from a Plasma Focus for medical applications

Abstract

The electron beam emitted from the back of Plasma Focus devices is being studied as a radiation source for IORT (IntraOperative Radiation Therapy) applications. A Plasma Focus device is being developed to this aim, to be utilized as an X-ray source. The electron beam is driven to impinge on 50 µm brass foil, where conversion X-rays are generated. Measurements with gafchromic film are performed to analyse the attenuation of the X-rays beam and to predict the dose given to the culture cell in radiobiological experiments to follow.

Enhancing radiosensitivity of melanoma cells through very high dose rate pulses released by a plasma focus device

“…The Monte Carlo simulation of the X-ray spectrum exhibited a component at 10 keV, and a component at 50 keV with a tail of up to 200 keV [ 32 ]. The dose assessment delivered in each shot has been extensively validated using Gafchromic ® films (EBT2/3) [ 26 ]. It was referred from dose measurements that photons reaching the cell layer had energies above 30 keV.…”

Analysis and characterization of the X‐ray beam produced by a PF device for radiotherapy applications

“…For each series, the film stack was irradiated with 16 discharges in the same operational conditions. Subsequent analysis yielded for the fractional factor the value 0.785 ± 0.05, consistent with the value found in Ceccolini et al [14] The average dose per discharge absorbed by the fourth film is presented in Fig. 3, where irradiation tests are reported in chronological order.…”

“…The production of X‐rays in the converter was simulated with the Monte Carlo (MC) N‐Particle code, using as input the electron beam as characterized . The dosimetric film stack used in measurements, as discussed in the succeeding texts, was included in the simulations. The results of the simulation are shown in Fig.…”

“…[12,13] The dosimetric film stack used in measurements, [14] as discussed in the succeeding texts, was included in the simulations. The results of the simulation are shown in Fig.…”

“…The Mylar® foil and the cell culture taken together are assumed to be essentially equivalent to a single EBT-3 film. The dose given to the cells can be estimated from a dose measurement on the third film, as discussed in Ceccolini et al [14] The discharge frequency has been kept at 1 discharge per minute, not to overheat the plasma chamber. The first sample has been irradiated with 8 discharges; 15 discharges were given to the second sample.…”