LET dependence of the response of a PTW-60019 microDiamond detector in a 62MeV proton beam.

This study was initiated following conclusions from earlier experimental work, performed in a low-energy carbon ion beam, indicating a significant LET dependence of the response of a PTW-60019 microDiamond detector. The purpose of this paper is to present a comparison between the response of the same PTW-60019 microDiamond detector and an IBA Roos-type ionization chamber as a function of depth in a 62MeV proton beam. Even though proton beams are considered as low linear energy transfer (LET) beams, the LET value increases slightly in the Bragg peak region. Contrary to the observations made in the carbon ion beam, in the 62MeV proton beam good agreement is found between both detectors in both the plateau and the distal edge region. No significant LET dependent response of the PTW-60019 microDiamond detector is observed consistent with other findings for proton beams in the literature, despite this particular detector exhibiting a substantial LET dependence in a carbon ion beam.

Rossomme S ，Denis JM ，Souris K ，Delor A ，Bartier F ，Dumont D ，Vynckier S ，Palmans H ... -  《-》

Dosimetric characterization of a microDiamond detector in clinical scanned carbon ion beams.

Marinelli M ，Prestopino G ，Verona C ，Verona-Rinati G ，Ciocca M ，Mirandola A ，Mairani A ，Raffaele L ，Magro G ... -  《-》

Dosimetric characteristics of four PTW microDiamond detectors in high-energy proton beams.

Marsolat F ，De Marzi L ，Patriarca A ，Nauraye C ，Moignier C ，Pomorski M ，Moignau F ，Heinrich S ，Tromson D ，Mazal A ... -  《-》

Response of synthetic diamond detectors in proton, carbon, and oxygen ion beams.

In this work, the LET-dependence of the response of synthetic diamond detectors is investigated in different particle beams. Measurements were performed in three nonmodulated particle beams (proton, carbon, and oxygen). The response of five synthetic diamond detectors was compared to the response of a Markus or an Advanced Markus ionization chamber. The synthetic diamond detectors were used with their axis parallel to the beam axis and without any bias voltage. A high bias voltage was applied to the ionization chambers, to minimize ion recombination, for which no correction is applied (+300 V and +400 V were applied to the Markus and Advanced Markus ionization chambers respectively). The ratio between the normalized response of the synthetic diamond detectors and the normalized response of the ionization chamber shows an under-response of the synthetic diamond detectors in carbon and oxygen ion beams. No under-response of the synthetic diamond detectors is observed in protons. For each beam, combining results obtained for the five synthetic diamond detectors and considering the uncertainties, a linear fit of the ratio between the normalized response of the synthetic diamond detectors and the normalized response of the ionization chamber is determined. The response of the synthetic diamond detectors can be described as a function of LET as (-6.22E-4 ± 3.17E-3) • LET + (0.99 ± 0.01) in proton beam, (-2.51E-4 ± 1.18E-4) • LET + (1.01 ± 0.01) in carbon ion beam and (-2.77E-4 ± 0.56E-4) • LET + (1.03 ± 0.01) in oxygen ion beam. Combining results obtained in carbon and oxygen ion beams, a LET dependence of about 0.026% (±0.013%) per keV/μm is estimated. Due to the high LET value, a LET dependence of the response of the synthetic diamond detector was observed in the case of carbon and oxygen beams. The effect was found to be negligible in proton beams, due to the low LET value. The under-response of the synthetic diamond detector may result from the recombination of electron/hole in the thin synthetic diamond layer, due to the high LET-values. More investigations are required to confirm this assumption.

Rossomme S ，Marinelli M ，Verona-Rinati G ，Romano F ，Cirrone PAG ，Kacperek A ，Vynckier S ，Palmans H ... -  《-》

Under-response of a PTW-60019 microDiamond detector in the Bragg peak of a 62 MeV/n carbon ion beam.

Rossomme S ，Hopfgartner J ，Vynckier S ，Palmans H ... -  《-》