Reconfiguring a Plane-Parallel Transmission Ionization Chamber to Extend the Operating Range into the Ultra-High Dose-per-pulse Regime
Konradsson, Elise LU ; Szecsenyi, Rebecka Ericsson LU ; Wahlqvist, Pontus ; Thoft, Andreas ; Blad, Börje LU ; Bäck, Sven Å.J. LU ; Ceberg, Crister LU
and Petersson, Kristoffer
LU
(2024)
In Radiation Research
201(3).
p.252-260
- Abstract
This study aims to investigate the feasibility of enhancing the charge collection efficiency (CCE) of a transmission chamber by reconfiguring its design and operation. The goal was to extend the range of dose-per-pulse (DPP) values with no or minimal recombination effects up to the ultra-high dose rate (UHDR) regime. The response of two transmission chambers, with electrode distance of 1 mm and 0.6 mm, respectively, was investigated as a function of applied voltage. The chambers were mounted one-by-one in the electron applicator of a 10 MeV FLASH-modified clinical linear accelerator. The chamber signals were measured as a function of nominal DPP, which was determined at the depth of dose maximum using EBT-XD film in solid water and... (More)
This study aims to investigate the feasibility of enhancing the charge collection efficiency (CCE) of a transmission chamber by reconfiguring its design and operation. The goal was to extend the range of dose-per-pulse (DPP) values with no or minimal recombination effects up to the ultra-high dose rate (UHDR) regime. The response of two transmission chambers, with electrode distance of 1 mm and 0.6 mm, respectively, was investigated as a function of applied voltage. The chambers were mounted one-by-one in the electron applicator of a 10 MeV FLASH-modified clinical linear accelerator. The chamber signals were measured as a function of nominal DPP, which was determined at the depth of dose maximum using EBT-XD film in solid water and ranged from 0.6 mGy per pulse to 0.9 Gy per pulse, for both the standard voltage of 320 V and the highest possible safe voltage of 1,200 V. The CCE was calculated and fitted with an empirical logistic function that incorporated the electrode distance and the chamber voltage. The CCE decreased with increased DPP. The CCE at the highest achievable DPP was 24% (36%) at 320 V and 51% (82%) at 1,200 V, for chambers with 1 mm (0.6 mm) electrode distance. For the combination of 1,200 V- and 0.6-mm electrode distance, the CCE was»100% for average dose rate up to 70 Gy/s at the depth of dose maximum in the phantom at a source-to-surface distance of 100 cm. Our findings indicate that minor modifications to a plane-parallel transmission chamber can substantially enhance the CCE and extending the chamber's operating range to the UHDR regime. This supports the potential of using transmission chamber-based monitoring solutions for UHDR beams, which could facilitate the delivery of UHDR treatments using an approach similar to conventional clinical delivery.
(Less)
- author
- Konradsson, Elise
LU
; Szecsenyi, Rebecka Ericsson
LU
; Wahlqvist, Pontus
; Thoft, Andreas
; Blad, Börje
LU
; Bäck, Sven Å.J.
LU
; Ceberg, Crister
LU
and Petersson, Kristoffer
LU
- organization
- publishing date
- 2024-03-08
- type
- Contribution to journal
- publication status
- published
- subject
- in
- Radiation Research
- volume
- 201
- issue
- 3
- pages
- 9 pages
- publisher
- Radiation Research Society
- external identifiers
-
- pmid:38308528
- scopus:85187204956
- ISSN
- 0033-7587
- DOI
- 10.1667/RADE-23-00177.1
- language
- English
- LU publication?
- yes
- id
- c097faed-32b8-4d8b-a60c-5a5ed1cd1f11
- date added to LUP
- 2024-04-10 13:49:24
- date last changed
- 2024-04-24 16:45:24
@article{c097faed-32b8-4d8b-a60c-5a5ed1cd1f11,
abstract = {{<p>This study aims to investigate the feasibility of enhancing the charge collection efficiency (CCE) of a transmission chamber by reconfiguring its design and operation. The goal was to extend the range of dose-per-pulse (DPP) values with no or minimal recombination effects up to the ultra-high dose rate (UHDR) regime. The response of two transmission chambers, with electrode distance of 1 mm and 0.6 mm, respectively, was investigated as a function of applied voltage. The chambers were mounted one-by-one in the electron applicator of a 10 MeV FLASH-modified clinical linear accelerator. The chamber signals were measured as a function of nominal DPP, which was determined at the depth of dose maximum using EBT-XD film in solid water and ranged from 0.6 mGy per pulse to 0.9 Gy per pulse, for both the standard voltage of 320 V and the highest possible safe voltage of 1,200 V. The CCE was calculated and fitted with an empirical logistic function that incorporated the electrode distance and the chamber voltage. The CCE decreased with increased DPP. The CCE at the highest achievable DPP was 24% (36%) at 320 V and 51% (82%) at 1,200 V, for chambers with 1 mm (0.6 mm) electrode distance. For the combination of 1,200 V- and 0.6-mm electrode distance, the CCE was»100% for average dose rate up to 70 Gy/s at the depth of dose maximum in the phantom at a source-to-surface distance of 100 cm. Our findings indicate that minor modifications to a plane-parallel transmission chamber can substantially enhance the CCE and extending the chamber's operating range to the UHDR regime. This supports the potential of using transmission chamber-based monitoring solutions for UHDR beams, which could facilitate the delivery of UHDR treatments using an approach similar to conventional clinical delivery.</p>}},
author = {{Konradsson, Elise and Szecsenyi, Rebecka Ericsson and Wahlqvist, Pontus and Thoft, Andreas and Blad, Börje and Bäck, Sven Å.J. and Ceberg, Crister and Petersson, Kristoffer}},
issn = {{0033-7587}},
language = {{eng}},
month = {{03}},
number = {{3}},
pages = {{252--260}},
publisher = {{Radiation Research Society}},
series = {{Radiation Research}},
title = {{Reconfiguring a Plane-Parallel Transmission Ionization Chamber to Extend the Operating Range into the Ultra-High Dose-per-pulse Regime}},
url = {{http://dx.doi.org/10.1667/RADE-23-00177.1}},
doi = {{10.1667/RADE-23-00177.1}},
volume = {{201}},
year = {{2024}},
}