Semiconductor nuclear radiation detectors made from tertiary and quaternary compounds of cadmium telluride (CdTe) can operate at room temperature without cryogenic cooling. One of such materials that have become of gr...Semiconductor nuclear radiation detectors made from tertiary and quaternary compounds of cadmium telluride (CdTe) can operate at room temperature without cryogenic cooling. One of such materials that have become of great interest is cadmium zinc telluride selenide (CdZnTeSe). Compared to other CdTe-based materials, such as cadmium zinc telluride (CdZnTe), CdZnTeSe can be grown with much less Te inclusions and sub-grain boundary networks. Chemical etching is often used to smoothen wafer surfaces during detector fabrication. This paper presents the characterization of CdZnTeSe that is chemically etched using bromine methanol solution. Infrared imaging shows that the wafer has no sub-grain boundary networks that often limit detector performance. The current-voltage (I-V) characterization experiment gave a resistivity of 4.6 × 10<sup>10</sup> Ω-cm for the sample. The I-V curve was linear in the ±10 to ±50 volts range. An energy resolution of 7.2% was recorded at 100 V for the 59.6-keV gamma line of <sup>241</sup>Am.展开更多
In the present work, we have measured the radon gas concentrations in tap water samples are taken directly from drinking tap water in sites houses being carried in Thi-Qar governorate by using nuclear track detector (...In the present work, we have measured the radon gas concentrations in tap water samples are taken directly from drinking tap water in sites houses being carried in Thi-Qar governorate by using nuclear track detector (CR-39). The results of measurements have shown that the highest average radon concentration in water samples is found in AL-Refai region which is equal to (0.223 ± 0.03 Bq/L), while the lowest average radon gas concentration is found in AL-Fajr region which is equal to (0.108 ± 0.01 Bq/L), with an average value of (0.175 ± 0.03 Bq/L). The highest value of annual effective dose (AED) in tap water samples is found in AL-Refai region, which is equal to (0.814 μSv/y), while the lowest value of (AED) is found in AL-Fajr region which is equal to (0.394 μSv/y), with an average value of (0.640 ± 0.1 μSv/y). The present results have shown that radon gas concentrations in tap water samples are less than the recommended international value (11.1 Bq/L). There for tap water in all the studied sites in Thi-Qar governorate is safe as for as radon concentration being concerned.展开更多
Cadmium zinc telluride selenide (CdZnTeSe) is a new semiconductor material for gamma-ray detection and spectroscopy applications at room temperature. It has very high crystal quality compared to similar materials such...Cadmium zinc telluride selenide (CdZnTeSe) is a new semiconductor material for gamma-ray detection and spectroscopy applications at room temperature. It has very high crystal quality compared to similar materials such as cadmium telluride and cadmium zinc telluride. The consistency of peak position in radiation detection devices is important to practical applications. In this paper, we have characterized a CdZnTeSe planar detector for bias voltages in the range of -20 V to -200 V and amplifier shaping time of 2, 3 and 6 μs. The peak position of the 59.6-keV gamma line of <sup>241</sup>Am becomes more stable as the absolute value of the applied voltage increases. The best energy resolution of 8.5% was obtained for the 59.6-keV gamma peak at -160 V bias voltage and 3-μs shaping time. The energy resolution was relatively stable in the -120 V to -200 V range for a 6-μs shaping time. Future work will be focused on the study of the peak position and energy resolution over time.展开更多
On the basis of previous research achievements of measuring the solid state nuclear track in apatite by thermal analysis method, the author further proposes the research program to measure the energy deposited by the ...On the basis of previous research achievements of measuring the solid state nuclear track in apatite by thermal analysis method, the author further proposes the research program to measure the energy deposited by the solid state nuclear track contained in zircon, sphene, epidote, apatite and other samples, in order to study the geological age and geothermal history. Compared with the measurement of nuclear track density by etching method, this one does not need to conduct so many processing programs for samples, but can improve the measurement accuracy.展开更多
The nuclear charge pickup cross sections of 84Kr on CH2,C,and Al targets are investigated using CR-39 nuclear track detector at the highest energy of 395 MeV/u.The cross sections for H are calculated from those measur...The nuclear charge pickup cross sections of 84Kr on CH2,C,and Al targets are investigated using CR-39 nuclear track detector at the highest energy of 395 MeV/u.The cross sections for H are calculated from those measured on C and CH2 targets.The dependence of the charge pickup cross section on target mass is studied.展开更多
The silicon-based diodes coated with a thin film of neutron reactive materials have been shown to produce excellent neutron detectors. We have fabricated the thin-film-coated single Si-PIN neutron detectors and stacke...The silicon-based diodes coated with a thin film of neutron reactive materials have been shown to produce excellent neutron detectors. We have fabricated the thin-film-coated single Si-PIN neutron detectors and stacked ones coupled in series and parallel in this work. The stacked detectors show the advantage of improving the detection efficiency of neutron detecting, which essentially attributes to the increase of the effective detection area. It is shown that the stacked detector in series has more superior performance than the parallel one. This work provides a feasible method to develop solid-state semiconductor neutron detectors with high neutron detection efficiency and high response speed.展开更多
Objective To investigate the annual effective doses from indoor radon received by academic staff in the Faculty building. Methods Measurements of indoor radon concentrations were performed in the Arts and Sciences Fac...Objective To investigate the annual effective doses from indoor radon received by academic staff in the Faculty building. Methods Measurements of indoor radon concentrations were performed in the Arts and Sciences Faculty of Dokuz Eylul University for two surveys of about 1 month duration respectively using the SSNTD （Solid State Nuclear Track Detectors） method with LR115 detectors. Time integrated measurements comprised different locations inside the faculty building： classrooms, toilets, canteen and offices. Homes of academic staff were also tested for radon. Results The aritthmetic mean radon concentration is 161 Bq m-3 with a range between 40 and 335 Bq m-3 in the Faculty. Six offices and three classrooms have a radon concentration above 200 Bq m-3. The results show that the radon concentration in classrooms is generally higher than in offices. Based on the measured indoor radon data, the annual effective doses received by staff in the Faculty were estimated to range from 0.79 to 4.27 mSv, according to UNSCEAR methodology. The annual effective doses received by staff ranged from 0.78 to 4.20 mSv in homes. On average, the Faculty contributed 56% to the annual effective dose. Conclusion Reported values for radon concentrations and corresponding doses are within the ICRP recommended limits for workplaces.展开更多
The concentrations of 20 trace elements in several ceramics tiles and ceramic composites used in Egypt were elementally analyzed by neutron activation analysis(NAA) technique. The samples and standard were irradiate...The concentrations of 20 trace elements in several ceramics tiles and ceramic composites used in Egypt were elementally analyzed by neutron activation analysis(NAA) technique. The samples and standard were irradiated with reactor for 4 h(in the Second Research Egyptian Reactor(Et-RR-2)) with thermal neutron flux 5.9×10 13 n/(cm 2·s).The gamma-ray spectra obtained were measured for several times by means of the hyper pure germanium detection system(HPGe). Also a solid state nuclear track detector(SSNTD) CR-39, was used to measure the emanation rate of radon for these samples. The radium concentrations were found to vary from 0.39—3.59 ppm and the emanation rates were found to vary from (0.728—5.688) × 10 -4 kg/(m 2· s).The elemental analysis of the ceramic tiles and ceramic composites have a great importance in assigning the physical properties and in turn the quality of the material.展开更多
In this work, study of laser-induced ions is presented. The plasma was produced by focusing a Nd：YAG laser, with a wavelength of 1064 nm, a pulsed width of 9-14 ns, a power of 1.1 MW and energy of 10 mJ, on silver ta...In this work, study of laser-induced ions is presented. The plasma was produced by focusing a Nd：YAG laser, with a wavelength of 1064 nm, a pulsed width of 9-14 ns, a power of 1.1 MW and energy of 10 mJ, on silver target in vacuum （10-3 Torr= 1.3332 Pa）. The characteristics of ion streams were investigated by CR-39 detectors located at angles of 0°, 30°, 60° and 90° with respect to normal of the target. The distance between the silver target and each detector was 11 cm. The energy of silver ions was found ranging from 1.5 eV to 1.06E4 eV. There was a high concentration of ions with low energy as compared to those with high energy, showing the energy distribution amongst the ions. The flux of ions was maximum in the axial direction which was decreasing with the angle increase with respect to normal of the target, and finally became minimum in the radial direction. Hence the silver ions have shown anisotropic behaviour.展开更多
The CN-85 nuclear track detector has been implemented for determining uranium concentration in human urine sample for different radiation workers in different Iraqi government, hospitals （nuclear medicine unit worker...The CN-85 nuclear track detector has been implemented for determining uranium concentration in human urine sample for different radiation workers in different Iraqi government, hospitals （nuclear medicine unit worker, X-ray and MST worker {the ministry of science and technology}）, for different ages,gender and working years.The exposure method was used by immersing CN-85 detectors in urine samples for four weeks, then CN-track detectors were etched by 6.25 N NaOH for 90 mints. The alpha emitter＇s concentrations for urine samples were calculated in comparison with standard samples. The results show that the average of uranium concentration for nuclear medicine 1.2725 ppb, 1.1896 ppb for X-ray workers, 1.3858 ppb for MST, 1.412 for CTS worker, and 0.848 ppb for control peoples. The average uranium concentration for nuclear medicine, X-ray, MST, and CTS （meal only） workers was 1.277 ppb, 1.1969 ppb, 1.3858 ppb and 1.463 ppb. While 1.25 ppb, 1.158 ppb, 1.385 ppb, and 1.293 ppb for female respectively, while for control people was 0.849 ppb for meal and 0.846 ppb for female. The results of this work regarding the dependence of concentrations on the person＇s occupation, years of service, sex and age.展开更多
In the fabrication of a 48 mm×48 mm silicon micro-strip nuclear radiation detector with 96 strips on each side, a perfect P-N junction cannot be formed consistently by the one-step implantation process, and thus ...In the fabrication of a 48 mm×48 mm silicon micro-strip nuclear radiation detector with 96 strips on each side, a perfect P-N junction cannot be formed consistently by the one-step implantation process, and thus over 50% of strips produced do not meet application requirements. However, the method of stratified implantation not only avoids the P region between the surface of wafers and the P＋ region, but also overcomes the shadow effect. With the help of the stratified implantation process, a perfect functional P-N junction can be formed, and over 95% of strips meet application requirements.展开更多
The annealing process for boron implantation is a crucial step during large size nuclear radiation detector fabrication. It can reduce the lattice defects and the projection straggling. A two-step annealing process fo...The annealing process for boron implantation is a crucial step during large size nuclear radiation detector fabrication. It can reduce the lattice defects and the projection straggling. A two-step annealing process for boron implantation was developed instead of a one-step annealing process, and the reverse body resistance of a silicon micro-strip detector was significantly increased, which means that the performance of the detector was improved.展开更多
The aim of this study is to determine the radon and natural radioactivity concentra-tions of some building materials and to assess the radiation hazard associated with those mortar materials when they are used in the ...The aim of this study is to determine the radon and natural radioactivity concentra-tions of some building materials and to assess the radiation hazard associated with those mortar materials when they are used in the construction of dwellings.Radon measurements were realized by using LR-115 Type 2 solid state nuclear track detec-tors.Radon activity concentrations of these materials were found to vary between 130.00±11.40 and 1604.06±40.5 Bq m^(-3).The natural radioactivity in selected mortar materials was analyzed by using scintillation gamma spectroscopy.The activity concentrations for 226Ra,232Th and 40K for the studied mortar materials ranged from ND to 48.5±7.0 Bq kg^(-1),ND to 41.0±6.4 Bq kg^(-1)and ND to 720.4±26.8 Bq kg^(-1),respectively.Radium equivalent activities,external and internal hazard indexes,gamma and alpha indexes and absorbed gamma dose rates were calculated to assess the radiation hazard of the natural radioactivity in studied samples.The calculated Raeq values of all samples were found to be lower than the limit of 370 Bq kg-1 set for building materials.The estimated hazard index values were found to be under the unity and the absorbed dose rate values were also below the worldwide average of 84 nGy h^(-1).展开更多
文摘Semiconductor nuclear radiation detectors made from tertiary and quaternary compounds of cadmium telluride (CdTe) can operate at room temperature without cryogenic cooling. One of such materials that have become of great interest is cadmium zinc telluride selenide (CdZnTeSe). Compared to other CdTe-based materials, such as cadmium zinc telluride (CdZnTe), CdZnTeSe can be grown with much less Te inclusions and sub-grain boundary networks. Chemical etching is often used to smoothen wafer surfaces during detector fabrication. This paper presents the characterization of CdZnTeSe that is chemically etched using bromine methanol solution. Infrared imaging shows that the wafer has no sub-grain boundary networks that often limit detector performance. The current-voltage (I-V) characterization experiment gave a resistivity of 4.6 × 10<sup>10</sup> Ω-cm for the sample. The I-V curve was linear in the ±10 to ±50 volts range. An energy resolution of 7.2% was recorded at 100 V for the 59.6-keV gamma line of <sup>241</sup>Am.
文摘In the present work, we have measured the radon gas concentrations in tap water samples are taken directly from drinking tap water in sites houses being carried in Thi-Qar governorate by using nuclear track detector (CR-39). The results of measurements have shown that the highest average radon concentration in water samples is found in AL-Refai region which is equal to (0.223 ± 0.03 Bq/L), while the lowest average radon gas concentration is found in AL-Fajr region which is equal to (0.108 ± 0.01 Bq/L), with an average value of (0.175 ± 0.03 Bq/L). The highest value of annual effective dose (AED) in tap water samples is found in AL-Refai region, which is equal to (0.814 μSv/y), while the lowest value of (AED) is found in AL-Fajr region which is equal to (0.394 μSv/y), with an average value of (0.640 ± 0.1 μSv/y). The present results have shown that radon gas concentrations in tap water samples are less than the recommended international value (11.1 Bq/L). There for tap water in all the studied sites in Thi-Qar governorate is safe as for as radon concentration being concerned.
文摘Cadmium zinc telluride selenide (CdZnTeSe) is a new semiconductor material for gamma-ray detection and spectroscopy applications at room temperature. It has very high crystal quality compared to similar materials such as cadmium telluride and cadmium zinc telluride. The consistency of peak position in radiation detection devices is important to practical applications. In this paper, we have characterized a CdZnTeSe planar detector for bias voltages in the range of -20 V to -200 V and amplifier shaping time of 2, 3 and 6 μs. The peak position of the 59.6-keV gamma line of <sup>241</sup>Am becomes more stable as the absolute value of the applied voltage increases. The best energy resolution of 8.5% was obtained for the 59.6-keV gamma peak at -160 V bias voltage and 3-μs shaping time. The energy resolution was relatively stable in the -120 V to -200 V range for a 6-μs shaping time. Future work will be focused on the study of the peak position and energy resolution over time.
基金supported by the National Natural Science Foundation of China(No.11275237)Natural Science Foundation of Shaanxi Province,China(No.SJ08-A26)
文摘On the basis of previous research achievements of measuring the solid state nuclear track in apatite by thermal analysis method, the author further proposes the research program to measure the energy deposited by the solid state nuclear track contained in zircon, sphene, epidote, apatite and other samples, in order to study the geological age and geothermal history. Compared with the measurement of nuclear track density by etching method, this one does not need to conduct so many processing programs for samples, but can improve the measurement accuracy.
基金supported by the National Natural Science Foundation of China(Nos.11075100 and 11565001)。
文摘The nuclear charge pickup cross sections of 84Kr on CH2,C,and Al targets are investigated using CR-39 nuclear track detector at the highest energy of 395 MeV/u.The cross sections for H are calculated from those measured on C and CH2 targets.The dependence of the charge pickup cross section on target mass is studied.
文摘The silicon-based diodes coated with a thin film of neutron reactive materials have been shown to produce excellent neutron detectors. We have fabricated the thin-film-coated single Si-PIN neutron detectors and stacked ones coupled in series and parallel in this work. The stacked detectors show the advantage of improving the detection efficiency of neutron detecting, which essentially attributes to the increase of the effective detection area. It is shown that the stacked detector in series has more superior performance than the parallel one. This work provides a feasible method to develop solid-state semiconductor neutron detectors with high neutron detection efficiency and high response speed.
基金supported by a grant of The Scientific and Technical Research Council of Turkey(TUBiTAK)
文摘Objective To investigate the annual effective doses from indoor radon received by academic staff in the Faculty building. Methods Measurements of indoor radon concentrations were performed in the Arts and Sciences Faculty of Dokuz Eylul University for two surveys of about 1 month duration respectively using the SSNTD （Solid State Nuclear Track Detectors） method with LR115 detectors. Time integrated measurements comprised different locations inside the faculty building： classrooms, toilets, canteen and offices. Homes of academic staff were also tested for radon. Results The aritthmetic mean radon concentration is 161 Bq m-3 with a range between 40 and 335 Bq m-3 in the Faculty. Six offices and three classrooms have a radon concentration above 200 Bq m-3. The results show that the radon concentration in classrooms is generally higher than in offices. Based on the measured indoor radon data, the annual effective doses received by staff in the Faculty were estimated to range from 0.79 to 4.27 mSv, according to UNSCEAR methodology. The annual effective doses received by staff ranged from 0.78 to 4.20 mSv in homes. On average, the Faculty contributed 56% to the annual effective dose. Conclusion Reported values for radon concentrations and corresponding doses are within the ICRP recommended limits for workplaces.
文摘The concentrations of 20 trace elements in several ceramics tiles and ceramic composites used in Egypt were elementally analyzed by neutron activation analysis(NAA) technique. The samples and standard were irradiated with reactor for 4 h(in the Second Research Egyptian Reactor(Et-RR-2)) with thermal neutron flux 5.9×10 13 n/(cm 2·s).The gamma-ray spectra obtained were measured for several times by means of the hyper pure germanium detection system(HPGe). Also a solid state nuclear track detector(SSNTD) CR-39, was used to measure the emanation rate of radon for these samples. The radium concentrations were found to vary from 0.39—3.59 ppm and the emanation rates were found to vary from (0.728—5.688) × 10 -4 kg/(m 2· s).The elemental analysis of the ceramic tiles and ceramic composites have a great importance in assigning the physical properties and in turn the quality of the material.
文摘In this work, study of laser-induced ions is presented. The plasma was produced by focusing a Nd：YAG laser, with a wavelength of 1064 nm, a pulsed width of 9-14 ns, a power of 1.1 MW and energy of 10 mJ, on silver target in vacuum （10-3 Torr= 1.3332 Pa）. The characteristics of ion streams were investigated by CR-39 detectors located at angles of 0°, 30°, 60° and 90° with respect to normal of the target. The distance between the silver target and each detector was 11 cm. The energy of silver ions was found ranging from 1.5 eV to 1.06E4 eV. There was a high concentration of ions with low energy as compared to those with high energy, showing the energy distribution amongst the ions. The flux of ions was maximum in the axial direction which was decreasing with the angle increase with respect to normal of the target, and finally became minimum in the radial direction. Hence the silver ions have shown anisotropic behaviour.
文摘The CN-85 nuclear track detector has been implemented for determining uranium concentration in human urine sample for different radiation workers in different Iraqi government, hospitals （nuclear medicine unit worker, X-ray and MST worker {the ministry of science and technology}）, for different ages,gender and working years.The exposure method was used by immersing CN-85 detectors in urine samples for four weeks, then CN-track detectors were etched by 6.25 N NaOH for 90 mints. The alpha emitter＇s concentrations for urine samples were calculated in comparison with standard samples. The results show that the average of uranium concentration for nuclear medicine 1.2725 ppb, 1.1896 ppb for X-ray workers, 1.3858 ppb for MST, 1.412 for CTS worker, and 0.848 ppb for control peoples. The average uranium concentration for nuclear medicine, X-ray, MST, and CTS （meal only） workers was 1.277 ppb, 1.1969 ppb, 1.3858 ppb and 1.463 ppb. While 1.25 ppb, 1.158 ppb, 1.385 ppb, and 1.293 ppb for female respectively, while for control people was 0.849 ppb for meal and 0.846 ppb for female. The results of this work regarding the dependence of concentrations on the person＇s occupation, years of service, sex and age.
基金Supported by National Natural Science Foundation of China(11175223,11305231,11205220)
文摘In the fabrication of a 48 mm×48 mm silicon micro-strip nuclear radiation detector with 96 strips on each side, a perfect P-N junction cannot be formed consistently by the one-step implantation process, and thus over 50% of strips produced do not meet application requirements. However, the method of stratified implantation not only avoids the P region between the surface of wafers and the P＋ region, but also overcomes the shadow effect. With the help of the stratified implantation process, a perfect functional P-N junction can be formed, and over 95% of strips meet application requirements.
文摘The annealing process for boron implantation is a crucial step during large size nuclear radiation detector fabrication. It can reduce the lattice defects and the projection straggling. A two-step annealing process for boron implantation was developed instead of a one-step annealing process, and the reverse body resistance of a silicon micro-strip detector was significantly increased, which means that the performance of the detector was improved.
基金funded by the Scientific and Technological Research Council of Turkey(Project number:214M039).
文摘The aim of this study is to determine the radon and natural radioactivity concentra-tions of some building materials and to assess the radiation hazard associated with those mortar materials when they are used in the construction of dwellings.Radon measurements were realized by using LR-115 Type 2 solid state nuclear track detec-tors.Radon activity concentrations of these materials were found to vary between 130.00±11.40 and 1604.06±40.5 Bq m^(-3).The natural radioactivity in selected mortar materials was analyzed by using scintillation gamma spectroscopy.The activity concentrations for 226Ra,232Th and 40K for the studied mortar materials ranged from ND to 48.5±7.0 Bq kg^(-1),ND to 41.0±6.4 Bq kg^(-1)and ND to 720.4±26.8 Bq kg^(-1),respectively.Radium equivalent activities,external and internal hazard indexes,gamma and alpha indexes and absorbed gamma dose rates were calculated to assess the radiation hazard of the natural radioactivity in studied samples.The calculated Raeq values of all samples were found to be lower than the limit of 370 Bq kg-1 set for building materials.The estimated hazard index values were found to be under the unity and the absorbed dose rate values were also below the worldwide average of 84 nGy h^(-1).
