The structureoftheas-preparedandthermalannealedAg10As30S60 chalcogenide glassischaracterized
using theX-raydiffraction(XRD)andscanningelectronmicroscopy(SEM).Differentialscanning
calorimetry (DSC)curvesrecordedatfourdifferentheatingratesareanalyzedtodeterminetheglass
and crystallizationtransitiontemperatures,thermalstabilityandenthalpyrelease.Twoseparated
crystallization peaksareobservedintheDSCcurves.XRDresultsindicatetheprecipitationofAgAsS4
crystal phaseisresponsibleforthe first peak.NumerousphaseswithS8 dominant phaseareaccountable
for thesecondpeak.Thecrystallizationkineticssuchastheactivationenergyforthecrystallization(Ec),
the frequencyfactor(Ko) andthecrystallizationrateconstant K are determinedforeachcrystallization
stage. Theresultsshowthatthecrystallizationrateconstantforthe first crystallizationstageisaboutsix
times largerthanthatofthesecondcrystallizationstep.

An investigation of angular distribution of scattered gamma-rays is important to get information about an efficient arrangement of γ-ray detectors and it is necessary to design a real detection system of the inspection system by using a (γ, γ) interaction. Angular distribution of scattered gamma radiation from 11B at 4,440 keV from transition J π (5/2− → 3/2−) has been simulated by extended GEANT4. In the simulation, seven LaBr3:Ce detectors were recording the scattered photons from nuclear resonance fluorescence (NRF) process in a plane perpendicular to the incident polarized γ-ray beam. The γ-ray beam was assumed to be monoenergetic and linearly polarized with energy spread of 5%. All the LaBr3:Ce detectors were similar in the diameter of 1.5 in. and length of 3 in., positioned at seven different directions. Angular distribution of the scattered γ-rays is discussed in terms of the detectors’ positions with respect to the target and incident γ-ray beam. The result, which indicates the largest count rate from NRF signals is backward (135° and 225°) and forward (45° and 315°) directions with respect to the incident gamma-ray, is useful when using the NRF process in inspection of the special nuclear materials (SNM) like 235U and 239Pu.

An investigation of angular distribution of scattered gamma-rays is important to get information about an efficient arrangement of γ-ray detectors and it is necessary to design a real detection system of the inspection system by using a (γ, γ) interaction. Angular distribution of scattered gamma radiation from 11B at 4,440 keV from transition J π (5/2− → 3/2−) has been simulated by extended GEANT4. In the simulation, seven LaBr3:Ce detectors were recording the scattered photons from nuclear resonance fluorescence (NRF) process in a plane perpendicular to the incident polarized γ-ray beam. The γ-ray beam was assumed to be monoenergetic and linearly polarized with energy spread of 5%. All the LaBr3:Ce detectors were similar in the diameter of 1.5 in. and length of 3 in., positioned at seven different directions. Angular distribution of the scattered γ-rays is discussed in terms of the detectors’ positions with respect to the target and incident γ-ray beam. The result, which indicates the largest count rate from NRF signals is backward (135° and 225°) and forward (45° and 315°) directions with respect to the incident gamma-ray, is useful when using the NRF process in inspection of the special nuclear materials (SNM) like 235U and 239Pu.

A monochromatic gamma ray beam is attractive for isotope-specific material/medical imaging or non-destructive inspection. A laser Compton scattering (LCS) gamma ray source which is based on the backward Compton scattering of laser light on high-energy electrons can generate energy variable quasi-monochromatic gamma ray. Due to the principle of the LCS gamma ray, the direction of the gamma beam is limited to the direction of the high-energy electrons. Then the target object is placed on the beam axis, and is usually moved if spatial scanning is required. In this work, we proposed an electron beam transport system consisting of four bending magnets which can stick the collision point and control the electron beam direction, and a laser system consisting of a spheroidal mirror and a parabolic mirror which can also stick the collision point. Then the collision point can be placed on one focus of the spheroid. Thus gamma ray direction and collision angle between the electron beam and the laser beam can be easily controlled. As the results, travelling direction of the LCS gamma ray can be controlled under the limitation of the beam transport system, energy of the gamma ray can be controlled by controlling incident angle of the colliding beams, and energy spread can be controlled by changing the divergence of the laser beam.

A monochromatic gamma ray beam is attractive for isotope-specific material/medical imaging or non-destructive inspection. A laser Compton scattering (LCS) gamma ray source which is based on the backward Compton scattering of laser light on high-energy electrons can generate energy variable quasi-monochromatic gamma ray. Due to the principle of the LCS gamma ray, the direction of the gamma beam is limited to the direction of the high-energy electrons. Then the target object is placed on the beam axis, and is usually moved if spatial scanning is required. In this work, we proposed an electron beam transport system consisting of four bending magnets which can stick the collision point and control the electron beam direction, and a laser system consisting of a spheroidal mirror and a parabolic mirror which can also stick the collision point. Then the collision point can be placed on one focus of the spheroid. Thus gamma ray direction and collision angle between the electron beam and the laser beam can be easily controlled. As the results, travelling direction of the LCS gamma ray can be controlled under the limitation of the beam transport system, energy of the gamma ray can be controlled by controlling incident angle of the colliding beams, and energy spread can be controlled by changing the divergence of the laser beam.

A non-destructive inspection system for special nuclear materials (SNMs) hidden in a sea cargo has been developed. The system consists of a fast screening system using neutron generated by inertial electrostatic confinement (IEC) device and an isotope identification system using nuclear resonance fluorescence (NRF) measurements with laser Compton backscattering (LCS) gamma-rays has been developed. The neutron flux of 108 n/sec has been achieved by the IEC in static mode. We have developed a modified neutron reactor noise analysis method to detect fission neutron in a short time. The LCS gamma-rays has been generated by using a small racetrack microtoron accelerator and an intense sub-nano second laser colliding head-on to the electron beam. The gamma-ray flux has been achieved more than 105 photons/s. The NRF gamma-rays will be measured using LaBr3(Ce) scintillation detector array whose performance has been measured by NRF experiment of U-235 in HIGS facility. The whole inspection system has been designed to satisfy a demand from the sea port.

A non-destructive inspection system for special nuclear materials (SNMs) hidden in a sea cargo has been developed. The system consists of a fast screening system using neutron generated by inertial electrostatic confinement (IEC) device and an isotope identification system using nuclear resonance fluorescence (NRF) measurements with laser Compton backscattering (LCS) gamma-rays has been developed. The neutron flux of 108 n/sec has been achieved by the IEC in static mode. We have developed a modified neutron reactor noise analysis method to detect fission neutron in a short time. The LCS gamma-rays has been generated by using a small racetrack microtoron accelerator and an intense sub-nano second laser colliding head-on to the electron beam. The gamma-ray flux has been achieved more than 105 photons/s. The NRF gamma-rays will be measured using LaBr3(Ce) scintillation detector array whose performance has been measured by NRF experiment of U-235 in HIGS facility. The whole inspection system has been designed to satisfy a demand from the sea port.

We have been developing an active, non-destructive detection system based on nuclear resonance fluorescence (NRF) for inspecting special nuclear materials (SNMs) such as 235U in a container at a seaport. The study of the NRF yield dependence on the target thickness of SNMs is required to evaluate the performance of the inspection system. To this end, an NRF experiment has been performed using a laser Compton backscattering γ-ray beam line at New SUBARU in 208Pb. Cylindrical shaped natural lead targets with a 0.5 cm radius and varying thicknesses of 1.0, 1.44, and 3.05 cm were irradiated at a resonance energy of 7.332 MeV. The NRF yield was detected using two HPG detectors with relative efficiencies of 120% and 100% positioned at scattering angles of 90° and 130°, respectively, relative to the incident γ-ray beam. As a result, the NRF yield exhibited a saturation behavior for the thick lead target. An analytic treatment and Monte Carlo simulation using GEANT4 was performed to interpret the reaction yield (RY) of the NRF interaction. The simulation result is in good agreement with the experimental data for the target thickness dependence. The analytic treatment, the NRF RY model, is also in reasonable agreement.

The knowledge on radioactivity content of the various radionuclides in the
soil and rocks play an important role in health physics. The main aim of this
work is to estimate the concentrations of natural radionuclides 226Ra, 228Ra,
228Th, 232Th and 40k in soil and phosphate samples and, impact of the ElSabaea
phosphate factory on the human health. This can be investigated via
gamma-ray spectroscopy by 2 × 2 inch NaI(Tl) scintillation detector. The
range of 226Ra, 232Th and 40k were from 59.7±6.7 to 638.3±31.0, from 9.4±1.4
to 40.6±6.3,from 213.1±9.5 to 798.9±30.6 in Bq/kg respectively.

The knowledge on radioactivity content of the various radionuclides in the
soil and rocks play an important role in health physics. The main aim of this
work is to estimate the concentrations of natural radionuclides 226Ra, 228Ra,
228Th, 232Th and 40k in soil and phosphate samples and, impact of the ElSabaea
phosphate factory on the human health. This can be investigated via
gamma-ray spectroscopy by 2 × 2 inch NaI(Tl) scintillation detector. The
range of 226Ra, 232Th and 40k were from 59.7±6.7 to 638.3±31.0, from 9.4±1.4
to 40.6±6.3,from 213.1±9.5 to 798.9±30.6 in Bq/kg respectively.