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Register a new userMonitoring the Bragg peak location of 73 MeV/u carbon ions by means of prompt $gamma$-ray measurements
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E. Testa
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By means of a time-of-flight technique, we measured the longitudinal profile of prompt $gamma$-rays emitted by 73 MeV/u $^{13}$C ions irradiating a PMMA target. This technique allowed us to minimize the shielding against neutrons and scattered $gamma$-rays, and to correlate prompt gamma emission to the ion path. This correlation, together with a high counting rate, paves the way toward real-time monitoring of the longitudinal dose profile during ion therapy treatments. Moreover, the time correlation between the prompt gamma detection and the transverse position of the incident ions measured by a beam monitor can provide real-time 3D control of the irradiation.
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L shell line and total x-ray production cross sections in 78Pt, 79Au, 82Pb, 83Bi, 90Th, and 92U targets ionized by 4-6 MeV/u fluorine ions were measured. These cross sections are compared with available theories for L shell ionization using single- and multiple-hole fluorescence and the Coster-Kronig yields. The ECPSSR and the ECUSAR theories exhibit good agreement with the measured data, whereas, the FBA theory overestimates them by a factor of two. Although for the F ion charge states q = 6-8 the multiple-hole atomic parameters do not significantly differ from the single-hole values, after an account for the multiple-holes, our data are better in agreement with the ECUSAR than the ECPSSR theory.
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