Improvement of the moderator’s thermalization efficiency for 14 MeV neutrons in boron neutron capture therapy

Cheng, Daowen; Lu, Jingbin; Yang, Dong; Wang, Huidong; Ma, K.

doi:10.1007/s10967-011-1575-z

Cited by 7 publications

(5 citation statements)

References 8 publications

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“…We found the flux of gamma rays around the beryllium target is 10 10 /cm 2 .s. The gamma rays are produced mainly from interactions of protons with beryllium target through 9 Be(p,) 6 Li() reactions. A small number of gamma rays are also emitted from capture reaction followed by inelastic scattering through 9 Be(p,) 10 Be reactions [23].…”

Section: Protonmentioning

confidence: 99%

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Analysis of Particle Distribution in a Double Layer Beam Shaping Assembly Resulted From 30 Mev-Proton Reactions With Beryllium Target Using the Phits Program

et al. 2020

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An analysis on the distribution of particle flux emanating from reactions of 30 MeV-proton with beryllium target in a double layer beam shaping assembly (BSA) has been carried out using the PHITS program. It studies important parameters relating to the distribution of proton, neutron, and gamma. It is revealed that reactions of proton and beryllium in double layer BSA produce fast neutrons and other protons, resulting from certain reactions, and recoil protons from the interactions of fast neutrons and hydrogen atoms. Fast neutrons are distributed around beryllium target, moderator, reflector, and collimator. They are moderated by Al and LiF material. Epithermal neutrons spread along the moderator, with a distribution that is tapering down as it approaches the end of the collimator (aperture). During its travel along the moderator, an epithermal neutron decreases in energy to become a thermal neutron. The spectrum of neutron beam produced by the double layer BSA is wide, which indicates that the neutron beam exiting the aperture consists of three kinds of neutrons, dominated by epithermal neutronswith energy range 1 eV – 10 keV.

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Section: Protonmentioning

confidence: 99%

“…Evidence suggests that combining two suitable materials yields better quality. Using two-layered moderators combination, Dao-wen et al, (2012) [6] were able to improve moderation up to 19.3%. Adib et al, (2016) [7] combined two or more filter materials and succeeded to produce epithermal neutron beams within a range of 1.5 to 10 keV.…”

Section: Introductionmentioning

confidence: 99%

Analysis of Particle Distribution in a Double Layer Beam Shaping Assembly Resulted From 30 Mev-Proton Reactions With Beryllium Target Using the Phits Program

et al. 2020

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“…better intensity and quality from the evidence that combining two suitable materials yields better quality. Using two-layered moderators combination, Dao-wen et al (2012) were able to improve moderation up to 19.3%. Adib et al (2016) combined two or more filter materials and succeeded to produce epithermal neutron beams within a range of 1.5 to 10 keV.…”

Section: Irradiated By Epithermal Neutron Beam From Double Layer Beammentioning

confidence: 99%

Characteristics of Thermal Neutron Flux Distribution in a Phantom Irradiated by Epithermal Neutron Beam from Double Layer Beam Shaping Assembly (DBSA)

odin

Suparta

Hermanto

et al. 2019

Pak. j. sci. ind. res. Ser. A: phys. sci.

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A simulation study on the Double-layer Beam Shaping Assembly (DBSA) system has been carried out. This study used fast neutron beam resulting from reactions of 30 MeV protons with beryllium target. The MCNPX code was utilized to design the DBSA and the phantom as well as to calculate neutron flux on the phantom. The distribution of epithermal neutron flux and gamma in the DBSA and phantom were computed using the PHITS code. The spectrum of radiation beams generated by the DBSA shows the characteristics that the typical epithermal neutron flux of 1.0 x109 n/(cm2.s), the ratio of epithermal to the thermal and fast neutron flux of 344 and 85, respectively and the ratio of gamma dose to the epithermal neutron flux of 1.82 x 10-13 Gy.cm2. The test of epithermal neutron beams irradiation on the water phantom shows that epithermal neutrons are thermalized and penetrate the phantom up to 12 cm in depth. The maximum value of neutron flux is 1.1 x 109 n/(cm2.s) at a depth of 2 cm in phantom.

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“…Boron Neutron Capture Therapy (BNCT) is a very effective cancer treatment technique for several types of brain tumor (Dao-wen et al 2012;Marashi 2000;Perks et al 1988). This technique is based on the bombardment of Boron with low energy thermal neutron that yields alpha particles ( 4 He) and recoiling lithium nuclei ( 7 Li).…”

Section: Introductionmentioning

confidence: 99%

“…This technique is based on the bombardment of Boron with low energy thermal neutron that yields alpha particles ( 4 He) and recoiling lithium nuclei ( 7 Li). These charged particles have high kinetic energy to kill tumor cells (Bortolussi & Altieri 2007;Dao-wen et al 2012;Perks et al 1988), their short ranges in matters reduce the damage to healthy tissues surrounding the tumor. However, healthy cells are damaged during neutron beam irradiation.…”

Section: Introductionmentioning

confidence: 99%

Measurement of Neutron Flux and Gamma Dose Rate Distribution Inside a Water Phantom for Boron Neutron Capture Therapy Study at Dalat Research Reactor

Trinh¹,

Pham²,

Nhan³

et al. 2019

JSM

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Exposure dose rate to the tumor and surrounding cells during neutron beam irradiation in Boron Neutron Capture Therapy (BNCT) comes not only from heavy charged particles produced from the 10 B(n,α) 7 Li nuclear reaction, but also from neutron-induced reactions with other biological elements in living tissue, as well as from gamma rays leaked from the reactor core. At Dalat Research Reactor, Vietnam, the neutron and gamma dose rate distribution inside a water phantom were measured by using activation method and Thermoluminescent Dosimeter (TLD) detector, respectively. The results showed that effective thermal neutron dose rate along the center line of the water phantom had a maximum value of 479 mSv h -1 at 1 cm in phantom and then decreases rapidly to 4.87 mSv h -1 at 10 cm. The gamma dose rate along the center line of the water phantom also reach its maximum of 4.31 mSv h -1 at 1 cm depth and decreases to 1.16 mSv h -1 at 10 cm position. The maximum biological tumor dose rate was 1.74 Gy-eq h -1 , not high enough to satisfy the treatment requirement of brain tumors. However, the results of this work are important in supporting of BNCT study in the upcoming stages at Dalat Research Reactor. ABSTRAK Kadar dos pendedahan kepada tumor dan sel sekitarnya semasa pancaran sinaran neutron dalam Terapi Boron NeutronTertawan (BNCT) datang bukan sahaja daripada zarah berat bercas yang dihasilkan daripada tindak balas nuklear 10 B(n,α) 7 Li, tetapi juga daripada tindak balas neutron-teraruh daripada unsur biologi lain dalam tisu hidup, selain daripada sinar gama yang bocor daripada teras reaktor. Di Reaktor Penyelidikan Dalat, Vietnam, kadar pengagihan dos neutron dan gama dalam fantom air diukur masing-masing menggunakan kaedah pengaktifan dan pengesan Thermoluminescent Dosimeter (TLD). Keputusan menunjukkan bahawa kadar dos haba neutron yang berkesan sepanjang garis tengah fantom air mempunyai nilai maksimum 479 mSv h -1 pada 1 cm dalam phantom dan kemudian menurun dengan pantas kepada 4.87 mSv h -1 pada 10 cm. Kadar dos gama sepanjang garis tengah fantom air juga mencapai tahap maksimum 4.31 mSv h -1 pada kedalaman 1 cm dan menurun ke 1.16 mSv h -1 pada kedudukan 10 cm. Kadar dos maksimum tumor biologi adalah 1.74 Gy-eq h -1 namun tidak cukup tinggi untuk memenuhi keperluan rawatan tumor otak. Walau bagaimanapun, keputusan kajian ini adalah penting dalam menyokong pengajian BNCT pada peringkat akan datang di Reaktor Penyelidikan Dalat. Kata kunci: BNCT; fantom air; fluks haba neutron; kadar dos; pengesan TLD

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Improvement of the moderator’s thermalization efficiency for 14 MeV neutrons in boron neutron capture therapy

Cited by 7 publications

References 8 publications

Analysis of Particle Distribution in a Double Layer Beam Shaping Assembly Resulted From 30 Mev-Proton Reactions With Beryllium Target Using the Phits Program

Analysis of Particle Distribution in a Double Layer Beam Shaping Assembly Resulted From 30 Mev-Proton Reactions With Beryllium Target Using the Phits Program

Characteristics of Thermal Neutron Flux Distribution in a Phantom Irradiated by Epithermal Neutron Beam from Double Layer Beam Shaping Assembly (DBSA)

Measurement of Neutron Flux and Gamma Dose Rate Distribution Inside a Water Phantom for Boron Neutron Capture Therapy Study at Dalat Research Reactor

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