Measurement of the neutron fields produced by a 62MeV proton beam on a PMMA phantom using extended range Bonner sphere spectrometers

Amgarou, K.; Bedogni, R.; Domingo, C.; Esposito, A.; Gentile, A.; Carinci, G.; Russo, Salvatore F.

doi:10.1016/j.nima.2011.07.027

Cited by 36 publications

(25 citation statements)

References 31 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…5,6,8,9 Similarly, measurements of neutron spectral fluence within a proton therapy facility were previously done using dedicated Bonner sphere spectrometry (BSS) systems. 5,8,10,11 Neutron organ dose measurements have also been conducted using passive detectors such as superheated emulsions (bubble detectors), thermoluminescent detector (TLD), and solid state nuclear track detector (SSNTD) mainly. 3,8,[12][13][14] On the one hand, all these studies have shown that stray neutron radiation involved in proton therapy is not negligible (up to 10 mSv/proton Gy outside the clinical target volume), is facility dependent (with major effects arising from beam line elements and shielding design), and implicates neutrons of high energy (equal to the proton beam energy).…”

Section: Introductionmentioning

confidence: 99%

Measurement of stray radiation within a scanning proton therapy facility: EURADOS WG9 intercomparison exercise of active dosimetry systems

et al. 2015

Self Cite

View full text Add to dashboard Cite

show abstract

Section: Introductionmentioning

confidence: 99%

Measurement of stray radiation within a scanning proton therapy facility: EURADOS WG9 intercomparison exercise of active dosimetry systems

et al. 2015

Self Cite

View full text Add to dashboard Cite

show abstract

“…We developed an extended range Bonner sphere (ERBS) spectrometer with high-atomic-number (Z) shells placed within polyethylene spheres to increase high-energy response compared to a standard BSS. While various different ERBS systems [27][28][29][30][31] have been used to measure neutron spectra that extend up to very high energies, e.g., measurements of atmospheric radiation [32][33][34][35] and around nonmedical accelerators, 28,30,[36][37][38][39][40] this detection technique has not previously been used for measurement of neutron spectra associated with clinical proton therapy. The objectives of the present study were therefore to measure a secondary neutron spectrum using an ERBS, to report neutron fluence as a function of energy, and to calculate the ambient dose equivalent from proton therapy.…”

Section: Introductionmentioning

confidence: 99%

Secondary neutron spectrum from 250‐MeV passively scattered proton therapy: Measurement with an extended‐range Bonner sphere system

Howell

Burgett

2014

Medical Physics

View full text Add to dashboard Cite

Purpose: Secondary neutrons are an unavoidable consequence of proton therapy. While the neutron dose is low compared to the primary proton dose, its presence and contribution to the patient dose is nonetheless important. The most detailed information on neutrons includes an evaluation of the neutron spectrum. However, the vast majority of the literature that has reported secondary neutron spectra in proton therapy is based on computational methods rather than measurements. This is largely due to the inherent limitations in the majority of neutron detectors, which are either not suitable for spectral measurements or have limited response at energies greater than 20 MeV. Therefore, the primary objective of the present study was to measure a secondary neutron spectrum from a proton therapy beam using a spectrometer that is sensitive to neutron energies over the entire neutron energy spectrum. Methods: The authors measured the secondary neutron spectrum from a 250-MeV passively scattered proton beam in air at a distance of 100 cm laterally from isocenter using an extended-range Bonner sphere (ERBS) measurement system. Ambient dose equivalent H*(10) was calculated using measured fluence and fluence-to-ambient dose equivalent conversion coefficients. Results: The neutron fluence spectrum had a high-energy direct neutron peak, an evaporation peak, a thermal peak, and an intermediate energy continuum between the thermal and evaporation peaks. The H*(10) was dominated by the neutrons in the evaporation peak because of both their high abundance and the large quality conversion coefficients in that energy interval. The H*(10) 100 cm laterally from isocenter was 1.6 mSv per proton Gy (to isocenter). Approximately 35% of the dose equivalent was from neutrons with energies ≥20 MeV. Conclusions: The authors measured a neutron spectrum for external neutrons generated by a 250-MeV proton beam using an ERBS measurement system that was sensitive to neutrons over the entire energy range being measured, i.e., thermal to 250 MeV. The authors used the neutron fluence spectrum to demonstrate experimentally the contribution of neutrons with different energies to the total dose equivalent and in particular the contribution of high-energy neutrons (≥20 MeV). These are valuable reference data that can be directly compared with Monte Carlo and experimental data in the literature. © 2014 Author(s)

show abstract

“…The ER-BSS from INFN-LNF [16][17][18] consists of 14 polyethylene (PE) spheres, labelled with their diameter in inches: 0 = bare thermal neutron detector, 2 , 2.5 , 3 , 3.5 , 4 , 4.5 , 5 , 7 , 8 , 10 , plus three highenergy spheres, called ERS-1, ERS-2 (7 external diameter, with an internal 4 PE sphere surrounded by 1.27 cm of lead or copper, respectively) and ERS-3 (12 external diameter, with an internal 3.15 PE sphere surrounded by 1 cm of lead). The central thermal neutron detector is a cylindrical 4 × 4 mm 6 LiI(Eu) scintillator, whose pulse height distribution is used to discriminate thermal neutrons from the photon contribution.…”

Section: Bonner Sphere Spectrometermentioning

confidence: 99%

A neutron source for IGISOL-JYFLTRAP: Design and characterisation

et al. 2017

Self Cite

View full text Add to dashboard Cite

Abstract.A white neutron source based on the Be(p, nx) reaction for fission studies at the IGISOL-JYFLTRAP facility has been designed and tested. 30 MeV protons impinge on a 5 mm thick water-cooled beryllium disc. The source was designed to produce at least 10 12 fast neutrons/s on a secondary fission target, in order to reach competitive production rates of fission products far from the valley of stability. The Monte Carlo codes MCNPX and FLUKA were used in the design phase to simulate the neutron energy spectra. Two experiments to characterise the neutron field were performed: the first was carried out at The Svedberg Laboratory in Uppsala (SE), using an Extended-Range Bonner Sphere Spectrometer and a liquid scintillator which used the time-of-flight (TOF) method to determine the energy of the neutrons; the second employed Thin-Film Breakdown Counters for the measurement of the TOF, and activation foils, at the IGISOL facility in Jyväskylä (FI). Design considerations and the results of the two characterisation measurements are presented, providing benchmarks for the simulations.

show abstract

Measurement of the neutron fields produced by a 62MeV proton beam on a PMMA phantom using extended range Bonner sphere spectrometers

Cited by 36 publications

References 31 publications

Measurement of stray radiation within a scanning proton therapy facility: EURADOS WG9 intercomparison exercise of active dosimetry systems

Measurement of stray radiation within a scanning proton therapy facility: EURADOS WG9 intercomparison exercise of active dosimetry systems

Secondary neutron spectrum from 250‐MeV passively scattered proton therapy: Measurement with an extended‐range Bonner sphere system

A neutron source for IGISOL-JYFLTRAP: Design and characterisation

Contact Info

Product

Resources

About