Development and characterization of optical readout well-type glass gas electron multiplier for dose imaging in clinical carbon beams

Abstract

The use of carbon ion beams in cancer therapy (also known as hadron therapy) is steadily growing worldwide; therefore, the demand for more efficient dosimetry systems is also increasing because daily quality assurance (QA) measurements of hadron radiotherapy is one of the most complex and time consuming tasks. The aim of this study is to develop a two-dimensional dosimetry system that offers high spatial resolution, a large field of view, quick data response, and a linear dose-response relationship.We demonstrate the dose imaging performance of a novel digital dose imager using carbon ion beams for hadron therapy. The dose imager is based on a newly-developed gaseous detector, a well-type glass gas electron multiplier. The imager is successfully operated in a hadron therapy facility with clinical intensity beams for radiotherapy. It features a high spatial resolution of less than 1 mm and an almost linear dose-response relationship with no saturation and very low linear-energy-transfer dependence. Experimental results show that the dose imager has the potential to improve dosimetry accuracy for daily QA.

High-tolerance nickel metalized glass gas electron multiplier: development and performance evaluation

“…Micro-pattern gas detectors (MPGDs) are widely used in various applications such as high-energy physics experiments [1][2][3], neutron detectors [4,5], space dosimetry [6], soft X-ray imaging [7][8][9], directional dark matter searches [10], observation of the Migdal effect in neutron scattering with application to direct dark matter searches [11], hadron therapy dosimetry [12,13], and others [14], due to their good spatial resolution, suitability for measuring high-LET radiation, ability in particle tracking, relatively low cost for economically instrumenting large detection areas and low sensitivity to high-energy photons. MPGDs create a high electric field between a small gap of electrodes, which induces an electron avalanche and amplifies the signal.…”

Radiation-induced effects in glass windows for optical readout GEM-based detectors

“…Optical readout GEM-based detectors coupled to CCD/CMOS cameras used for particle therapy have been studied by several groups [2][3][4][5][6]. The setups included transparent exit windows, which were in some cases [2,6,7] , where it was either regarded as negligible [5] or easy to subtract [4].…”