Clusters of ionisation in nanometre targets for propane-experiments with a Jet Counter

Abstract

Further evidence on the reliability of the device called the Jet Counter (JC) for studying the formation of ionisation clusters at the nanometre level are presented. The new experimental data on the distributions of ionisation cluster size originating from a 2-10 nm size target in propane irradiated by 3.8 MeV alpha particles are described. The JC consists of a pulse-operated valve that injects an expanding jet of propane into an interaction chamber, where a sensitive volume in the form of a cylinder is created. The sensitive volume was irradiated by 3.8 MeV alpha particles. The resulting distribution of ion clusters, ranging from 2 to 10 nm in unit density gas, has been measured. A method of determining the efficiency of registration of single propane ions using an ion detector is described. A method of deconvolution of the measured to true cluster size distributions is also given. Finally, the measured cluster size distributions are compared with modelled distributions based on Monte Carlo calculations. The results for propane together with previous ones for nitrogen indicate the JC to be an efficient tool for the investigation of radiation quality at the nanometre level.

Energy dependent track structure parametrisations for protons and carbon ions based on nanometric simulations

“…With the help of such energy-dependent descriptions of nanodosimetric quantities like M 1 , a basis is created for a fast calculation of track structure properties. The ionisation cluster size distributions and the associated statistical parameters are measurable quantities [23][24][25][26][27] and could in the future − when practical instruments have been developed − be used in the clinic to characterise track structure and radiation quality of the treatment beam. In combination with a model predicting the radiobiological outcome − for example the RMF model that is linking double-strand break induction to reproductive cell death [28,29] − these parametrisations can be useful to achieve a higher accuracy for biological optimisation of treatment plans.…”

Track structure of light ions: experiments and simulations

“…distributions measured with ion-counting nanodosimeters and compared with distributions simulated by Monte Carlo codes based on the same physical assumptions and approximations(Garty et al 2002a, Bantsar et al 2004, Hilgers et al 2007.…”

Local weighting of nanometric track structure properties in macroscopic voxel geometries for particle beam treatment planning

“…The preeminent advantage of this nanometric characterization of particle track structure is that ICSDs and the associated statistical parameters are measurable quantities (Garty et al 2002a, 2002b, Bantsar et al 2004, Conte et al 2012. Hence, measurements of these quantities can be used to characterize track structure and radiation quality of the treatment beam.…”