• Book : 431()
• Pub. Date : 2025
• Page : pp.113675
• Keyword :

Abstract

Objective a previous study reported nanodosimetric measurements of therapeutic-energy carbon ions penetrating simulated tissue. The results are incompatible with the predicted mean energy of the carbon ions in the nanodosimeter and previous experiments with lower energy monoenergetic beams. The purpose of this study is to explore the origin of these discrepancies. Approach detailed simulations using the Geant4 toolkit were performed to investigate the radiation field in the nanodosimeter and provide input data for track structure simulations, which were performed with a developed version of the PTra code. Main results the Geant4 simulations show that with the narrow-beam geometry employed in the experiment, only a small fraction of the carbon ions traverse the nanodosimeter and their mean energy is between 12% and 30% lower than the values estimated using the SRIM software. Only about one-third or less of these carbon ions hit the trigger detector. The track structure simulations indicate that the observed enhanced ionization cluster sizes are mainly due to coincidences with events in which carbon ions miss the trigger detector. In addition, the discrepancies observed for high absorber thicknesses of carbon ions traversing the target volume could be explained by assuming an increase in thickness or interaction cross-sections in the order of 1%. Significance the results show that even with strong collimation of the radiation field, future nanodosimetric measurements of clinical carbon ion beams will require large trigger detectors to register all events with carbon ions traversing the nanodosimeter. Energy loss calculations of the primary beam in the absorbers are insufficient and should be replaced by detailed simulations when planning such experiments. Uncertainties of the interaction cross-sections in simulation codes may shift the Bragg peak position.

• Book : 11(1)
• Pub. Date : 2025
• Page : pp.015018
• Keyword :

Abstract

Ion implantation is widely utilised for the modification of inorganic semiconductors; however, the technique has not been extensively applied to lead halide perovskites. In this report, we demonstrate the modification of the optical properties of caesium lead bromide (CsPbBr3) thin films via noble gas ion implantation. We observed that the photoluminescence (PL) lifetimes of CsPbBr3 thin films can be doubled by low fluences (<1 × 10¹⁴ at·cm⁻²) of ion implantation with an acceleration voltage of 20 keV. We attribute this phenomenon to ion beam induced shallow minority charge carrier trapping induced by nuclear stopping, dominant by heavy noble gases (Ar, Xe). Simultaneously, the PL quantum yield (PLQY) is altered during noble gas ion implantation inversely correlates with the electronic stopping power of the implanted element, hence Ar implantation reduces the PLQY, while Ne even causes a PLQY enhancement. These results thus provide a guide to separate the effect of nuclear and electronic damage during ion implantation into halide perovskites.

• Book : 36(6)
• Pub. Date : 2025
• Page : pp.065202
• Keyword :

• Book : 178()
• Pub. Date : 2025
• Page : pp.105524
• Keyword :

• Book : 604()
• Pub. Date : 2025
• Page : pp.155469
• Keyword :

• Book : 604()
• Pub. Date : 2025
• Page : pp.155484
• Keyword :

• Book : 227()
• Pub. Date : 2025
• Page : pp.112393
• Keyword :

• Book : 227()
• Pub. Date : 2025
• Page : pp.112384
• Keyword :

• Book : 227()
• Pub. Date : 2025
• Page : pp.112392
• Keyword :

• Book : 228()
• Pub. Date : 2025
• Page : pp.112407
• Keyword :