A new solution for UHDP and UHDR (Flash) measurements: Theory and conceptual design of ALLS chamber.

Ultra-High dose-per-pulse regimens (UHDP), necessary to trigger the "FLASH" effect, still pose serious challenges to dosimetry. Dosimetry plays a crucial role, both to significantly improve the accuracy of the radiobiological experiments necessary to fully understand the mechanisms underlying the effect and its dependencies on the beam parameters, and to be able to translate such effect into clinical practice. The standard ionization chamber in UHDP region is significantly affected by the effects of the electric field generated by the enormous density of charges produced by the dose pulse. This work describes the theory and the conceptual design of a gas chamber (the ALLS chamber) which overcomes the above-mentioned problems.
Competing Interests: Declaration of Competing Interest F. Galante, G. Mariani, M. Pacitti and G. Felici are SIT employees; G. Felici is a SIT shareholder; A. Gasparini received a grant for a post doc position funded by SIT S.p.A. The remaining authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
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