Photoneutron spectrometry by novel multi-directional spherical neutron spectrometry system

Abstract

Neutron spectrometry in science and technology applications in general and accurate exotic photoneutron (PN) dosimetry of cancer patients undergoing high-dose high-energy X-rays therapy in medical accelerators in particular is of vital need. In this study, a novel passive multi-directional multi-detector neutron spectrometry system was developed and home-made using 6 polycarbonate/10B detectors on 6 sides of polyethylene (PE) cubes used bare and also embedded at center of PE spheres of 8 different diameters. The system provided well-resolved unfolded directional PN spectra showing thermal and fast PN peaks of 6 sides and mean spectrum in 5 field sizes at isocenter and other locations in 18 MV Siemens ONCOR medical linear accelerator bunker. The neutron spectrometry system developed has unique characteristics such as being simple, efficient, low cost, practical, and insensitive to low-LET radiation with well-resolved directional and mean spectra easily applicable in medicine, health, environment, science and technology in developing and developed laboratories.

Breakthrough on radon individual monitoring and protecting miners by novel dual-function monitor on respirator

“…The module also protects the detector from humidity keeping its sensitivity to radon 7–9 times higher than that of commonly used radon detectors 20 , 37 . Polycarbonate detector is flexible in size to be effectively used in different applications from small size (3 cm × 3 cm) as used in this study, in tissue-specific and energy-specific miniature dosimeter/spectrometers (3 cm × 3 cm) 33 , in multi-directional neutron spectrometry with polyethylene spheres (3 cm × 3 cm) 34 , in megasize in megasize radon monitors (40 cm × 80 cm) 21 , etc. Our studies have provided succssful and promissing results for applying the dual-function individual radon monitor for miners in real radon working environments as well as for individual radon monitoring indoors of houses.…”

“…Polycarbonate detector is flexible in size to be effectively used in different applications from small size (3 cm × 3 cm) as used in this study, in tissue-specific and energy-specific miniature dosimeter/spectrometers (3 cm × 3 cm) 33 , in multi-directional neutron spectrometry with polyethylene spheres (3 cm × 3 cm) 34 , in megasize in megasize radon monitors (40 cm × 80 cm) 21 , etc.…”

“…PCTDs when processed by an ECE method 29 , in particular under 50 Hz – HV electric field conditions, as recently studied by us, have been applied in many recent studies. Such novel studies include efficient monitoring of radon and progeny 20 ; breakthough on discovery of 4π ion distribution in plasma focus devices by 4π ion impage processing of hydrogen (proton) 31 , 32 , deuterium, helium or heavier ions 31 , 32 ; alpha particle detection in a wide energy range 21 ; megasize (40 cm × 80 cm) radon monitoring and ion image processing 21 , novel miniature neutron dosimeter/spectrometer for neutron dosimetry 33 , and passive novel multi-directional neutron spectrometry 34 .…”

Semi-experimental assessment of neutron equivalent dose and secondary cancer risk for off-field organs in glioma patients undergoing 18-MV radiotherapy

“…Fast neutrons emitting from the accelerator head can directly reach the patient's bed or slow down by interaction with the components of the treatment room, including walls, tables, and the like, and eventually, be converted into thermal neutrons [18]. Therefore, a spectrum of neutron energy is expected anywhere on the patient's bed [19,20].…”