New Methods for Measuring Neutron Spectra with Energy from 0.4 eV to 10 MeV by Track and Activation Detectors

Doroshenko, J.; Kraitor, S. N.; Кузнецова, Т. В.; Kushnereva, K. K.; Leonov, E.S.

doi:10.13182/nt77-a31791

Cited by 30 publications

(3 citation statements)

References 6 publications

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“…Users can also select from 14 detector response matrices and 58 starting spectra. 17 The SPUNIT 18 unfolding code was used for this work. The SPUNIT algorithm uses the following equation to iterate the fluences:…”

Section: Unfoldingmentioning

confidence: 99%

Investigation of secondary neutron dose for dynamic MLC IMRT delivery

et al. 2005

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Secondary neutron doses from the delivery of 18 MV conventional and intensity modulated radiation therapy (IMRT) treatment plans were compared. IMRT was delivered using dynamic multileaf collimation (MLC). Additional measurements were made with static MLC using a primary collimated field size of 10 x 10 cm2 and MLC field sizes of 0 x 0, 5 x 5, and 10 x 10 cm2. Neutron spectra were measured and effective doses calculated. The IMRT treatment resulted in a higher neutron fluence and higher dose equivalent. These increases were approximately the ratio of the monitor units. The static MLC measurements were compared to Monte Carlo calculations. The actual component dimensions and materials for the Varian Clinac 2100/2300C including the MLC were modeled with MCNPX to compute the neutron fluence due to neutron production in and around the treatment head. There is excellent agreement between the calculated and measured neutron fluence for the collimated field size of 10 x 10 cm2 with the 0 x 0 cm2 MLC field. Most of the neutrons at the detector location for this geometry are directly from the accelerator head with a small contribution from room scatter. Future studies are needed to investigate the effect of different beam energies used in IMRT incorporating the effects of scattered photon dose as well as secondary neutron dose.

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Section: Unfoldingmentioning

confidence: 99%

Investigation of secondary neutron dose for dynamic MLC IMRT delivery

et al. 2005

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“…Commencing with the Monte Carlo simulated neutron spectrum, results are iteratively varied and compared with the TLD data until a match is made, and the unfolded (experimental) spectrum is obtained. In the current work the unfolding algorithm referred in Doroshenko et al (1977) is employed along with the matrix response UTA4 (Hertel and Davidson 1985). As this matrix was developed for spheres with a scintillator 6 LiI (Eu) at the centre, a preliminary test was carried out to correlate the responses of 6 LiI (Eu) and TLD600.…”

Section: Bonner Spectrometrymentioning

confidence: 99%

Study of the neutron field in the vicinity of an unshielded PET cyclotron

et al. 2005

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The neutron field in the proximity of an unshielded PET cyclotron was investigated during 18F radioisotope production with an 18 MeV proton beam. Thermoluminescent detector (TLD) models TLD600 and TLD700 as well as Bonner moderating spheres were irradiated at different positions inside the vault room where the cyclotron is located to determine the thermal neutron flux, neutron spectrum and dose equivalent. Furthermore, from a combination of measurements and Monte Carlo simulations the neutron source intensity at the target was estimated. The resulting intensity is in good agreement with the IAEA recommendations. Neutron doses derived from the measured spectra were found to vary between 7 and 320 mSv per 1 microA h of proton-integrated current. Finally, gamma doses were determined from TLD700 readings and amounted to around 10% of the neutron doses.

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“…In this work and most work previously done at Georgia Tech, the SPUNIT algorithm was used in the unfolding process. [4] SPUNIT is an adaptation of the method described by Doroschenko [5] and is based on the application of that method in the U.S. Naval Research Laboratory code BUNKI.…”

Section: Bonner Sphere Spectrometermentioning

confidence: 99%

Neutron dose equivalent rates in the vicinity of waste containers containing TRU

Hertel

Liang²,

Cahill³

et al. 2014

Progress in Nuclear Science and Technology

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The Transuranic Waste Processing Center is charged with treating, packaging and shipping TRU waste for disposal in a safe and efficient manner. The nature of TRU waste, i.e. it contains radionuclides which spontaneous fission and emit alpha particles which can lead to the production of (α,n) neutrons, can lead to neutron dose equivalent rates of radiation protection concern. Neutron dosimetry measurements were performed at the TWPC facility in locations where neutron dose equivalent rates of significance had been observed using neutron survey instruments. These measurements provide an assessment of the dosimetric properties of neutron fields that are deemed to be typical at the TWPC. The neutron measurements were performed at four locations using a Bonner sphere spectrometer which provides a low resolution spectrum that yields a good estimate of the neutron dose equivalent rate and the fluence rate. A tissue equivalent proportional counter dose equivalent measurement was performed at one location. Based on the Bonner sphere measurements, over 90% of the ambient dose equivalent is delivered between approximately 100 keV and 7.4 MeV.

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New Methods for Measuring Neutron Spectra with Energy from 0.4 eV to 10 MeV by Track and Activation Detectors

Cited by 30 publications

References 6 publications

Investigation of secondary neutron dose for dynamic MLC IMRT delivery

Investigation of secondary neutron dose for dynamic MLC IMRT delivery

Study of the neutron field in the vicinity of an unshielded PET cyclotron

Neutron dose equivalent rates in the vicinity of waste containers containing TRU

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