[en] The Pohang Neutron Facility consists of an electron linear accelerator, a water-cooled Ta target, and an 11-m time-of-flight path which has been constructed for nuclear data production. It has been equipped with a new four-position sample changer controlled remotely by a CAMAC data acquisition system, which allows simultaneous accumulation of the neutron time of flight spectra from 4 different detectors. The neutron total cross-sections of natural Dy, In and Cu were measured in the neutron energy range from 0.1 eV to 100 eV by using the neutron time of flight method with the new data acquisition system. A ⁶LiZnS(Ag) glass scintillator was used as a neutron detector and metallic plates of natural Dy, In and Cu samples were used for the neutron transmission measurement. The neutron flight path from the water-cooled Ta target to the neutron detector was 10.81±0.02 m. The background level was determined by using notch-filters of Co, Ta, and Cd sheets. In order to reduce the gamma rays from Bremsstrahlung and those from neutron capture, we employed a neutron-gamma separation system based on their different pulse shapes. The present measurements are in general agreement with the evaluated data in ENDF/B-VI. The resonance parameters of the Dy and In isotopes were extracted from the transmission data and compared with the previous ones. (author)

[en] Highlights: • Study of heavy ion response of lanthanum halide detectors. • Experimental measurements of He and Si heavy ions beams at the Heavy Ion Medical Accelerator in Chiba (HIMAC). • Comparison of experimentally measured spectra and PHITS simulations. • Study of LaBr₃ scintillation from heavy ion tracks. Lanthanum Halide scintillators such as lanthanum bromide (LaBr₃:Ce) and lanthanum chloride (LaCl₃:Ce) have been studied extensively in gamma radiation fields and have shown to be excellent gamma ray detectors. Measurements with these detectors in complex radiation fields that include neutrons, protons and heavy ions may produce some information about the radiation field. For example fast neutron (n,γ), (n,p), and (n,α) reactions produce scintillations in the crystal from the energy deposited by the resulting secondary particles. Also high energy radiation environments such as those encountered in spacecraft and high energy charged particle facilities contain protons and heavy ions with enough energy to penetrate typical scintillation detectors. The light produced in the crystal by these heavy ions is proportional to the energy deposited along the ion track. To investigate the response of LaBr₃ detectors to heavy ions, a series of experiments have been carried out at the Heavy Ion Medical Accelerator in Chiba, Japan (HIMAC). Measurements with He and Si ions with various incident energies have been performed and the light output of the scintillator has been measured. The experimentally measured spectra have been compared to simulations using the particle and heavy ion transport system (PHITS) code and quenching effects have been observed in the measured spectra. The quenching of the Si ion experiments is greater than the quenching observed in the He ion experiments. The results from both simulation and experiment are presented and discussed.

[en] The neutron total cross-section of natural Dy has been measured in the energy region from 0.025 eV to 100 eV by the neutron time-of-flight method at Pohang Neutron Facility, which consists of an electron linear accelerator, a water-cooled Ta target with a water moderator, and a time-of-flight path with an 11 m length. A ⁶Li-ZnS(Ag) scintillator with a diameter of 12.5 cm and a thickness of 1.5 cm has been used as a neutron detector and a metallic plate of Dy sample have been used for the neutron transmission measurement. The background level has been determined by using notch-filters of Co, Ta, and Cd sheets. In order to reduce the gamma rays from a Bremsstrahlung and that from a neutron capture, we have employed a neutron-gamma separation system based on their different pulse shape. The present measurements are in general agreement with the previous ones and the evaluated data in ENDF/B-VI. The resonance parameters of Dy isotopes (^161,162,163Dy) have been extracted from the transmission data by using the SAMMY code and compared with the previous ones

[en] The Pohang Neutron Facility consists of an electron linear accelerator, a water-cooled Ta target, and an 11-m time-of-flight path which has been constructed for nuclear data production. It has been equipped with a new four-position sample changer controlled remotely by a CAMAC data acquisition system, which allows simultaneous accumulation of the neutron time of flight spectra from 4 different detectors. The neutron total cross-sections of natural In and Cu were measured in the neutron energy range from 0.1eV to 100 eV by using the neutron time of flight method with the new data acquisition system. A ⁶LiZnS(Ag) glass scintillator was used as a neutron detector and metallic plates of natural In and Cu samples were used for the neutron transmission measurement. The neutron flight path from the water-cooled Ta target to the neutron detector was 10.81 ± 0.02m. The background level was determined by using notch-filters of Co, Ta, and Cd sheets. In order to reduce the gamma rays from Bremsstrahlung and those from neutron capture, we employed a neutron-gamma separation system based on their different pulse shapes. The present measurements are in general agreement with the evaluated data in ENDF/B-VI. The resonance parameters of the In isotope (¹¹⁵In) were extracted from the transmission data and compared with the previous ones

[en] We have developed new space radiation dosimeters onboard the International Space Station (ISS). In this year, the developed tissue equivalent proportional counters (TEPC) which gives lineal energy of individual charged particles and bubble detectors (BD) which is generally employed as neutron dosimeters were calibrated with proton 70 MeV at NIRS-Cyclotron. The calibration campaign with heavy ions at HIMAC covers whole range of space radiation from protons to iron ions, which will allow the successful radiation dosimetry in space environment. (author)

[en] The Pohang Neutron Facility, which is based on an electron linear accelerator, has been equipped with a new CAMAC data acquisition system consisting of a neutron-gamma separation circuit and a four-position sample changer for nuclear data production and for basic science experiments using neutrons. The system has been tested by measuring the neutron flux and the neutron total cross-sections of natural W and Ti samples with the ⁶Li-ZnS (Ag) scintillator by using the neutron time-of-flight method. The measured neutron total cross-sections are compared with other measured data and the evaluation data in ENDF/B-VI. The present measurements are in generally good agreement with other data and the evaluated data.