Dose distribution of proton beams with NMR measurements of Fricke-agarose gels.
Fricke-agarose gels have been irradiated with a proton beam. Then samples have been extracted at different depths with respect to the beam penetration distance, corresponding to different irradiation doses. Relaxation times T1 and T2, measured at 17 MHz, appear sensitive to this kind of radiation. In particular, T2 exhibits three components T2a, T2b and T2c, the first two being sensitive to proton irradiation. At 1% agarose concentration, the relaxation rates R1 = 1/T1, R2a = 1/T2a and R2b = 1/T2b of samples irradiated with both modulated and unmodulated beams, increase with the dose, irrespective of the beam energy. The yield G of Fe3+ ions per 100 eV of absorbed energy is always higher than that obtained for gamma irradiated samples.
Di Capua
S
S
Laboratorio di Fisica e INFN Sezione Sanità, Istituto Superiore di Sanita', Roma Italy.
D'Errico
F
F
Egger
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E
Guidoni
L
L
Luciani
A M
AM
Rosi
A
A
Viti
V
V
D005296:Ferrous Compounds; D005782:Gels; D006801:Humans; D018499:Linear Energy Transfer; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D011522:Protons; D011874:Radiometry / Q000295:instrumentation / Q000379:methods*; D011879:Radiotherapy Dosage; D011882:Radiotherapy, High-Energy; D012685:Sepharose; D012996:Solutions
D005296:Ferrous Compounds; C075364:Fricke solution; D005782:Gels; D011522:Protons; D012996:Solutions; D012685:Sepharose