Gamma-ray Spectroscopy Techniques Research Articles

Determination of the Concentration of 40K of Mudstone in Northern Iraq by Using Gamma Ray Spectroscopy and Flame Photometry Technique

The study of natural radionuclide materials is important to assess the health hazards on human being and one of these materials is 40 K which is present in soil and different types of stones. This study is performed to assess the 40K concentration in mudstones in the north of Iraq by (flame photometry and γ-ray spectroscopy) and to compare between these two techniques in measuring its level. So the activity of potassium was measured by these methods, and their results were compared with the results of other studies. The results show that the concentration of 40K ranges from 284.3 Bq/kg to 2481.2 Bq/kg using γ-ray spectroscopy and 511.7 Bq/kg to 3623.6 Bq/kg using flame photometer technique and these results were comparable with the upper level of the world mean specific concentration of 40K and cause no health hazard. The results obtained by the two methods were also, compared using T-test and P-value and they show no statistical significant difference.

Radioactive contamination of the atmosphere of Cairo, Egypt, from the Fukushima Dai-ichi nuclear plant accident

Radioactive contamination in air dust particles of Cairo atmosphere from the Fukushima accident was detected by the gamma-ray spectroscopy technique. Analysis of the spectra obtained by using an High-Purity Germanium detector showed that there were some traces of 131I and 134, 137Cs. Estimate and study of concentration of those radionuclides were done over a period of about 5 months after the accident. Comparison with corresponding results in different countries all over the world has been performed.

Preliminary investigation of naturally occurring radionuclide in some six representative cement types commonly used in Cameroon as building material

The present study was aimed at the determination of the specific activity of naturally occurring radionuclides and evaluation of the radiological health hazards in 24 cement samples representing six cement types commonly used in Cameroon for building construction have been analyzed. A high purity germanium detector spectrometer was used for quantification of gamma emitting radionuclide in the cements to demonstrate the radiological health hazards. Terrestrial absorbed dose rate (D), annual effective dose, radium equivalent activity, external/internal hazard index, activity gamma and alpha index caused by gamma emitting natural radionuclide are determined from the obtained values of 226 Ra, 232 Th and 40 K. The calculated values of the absorbed dose rate and the indoor annual effective dose are slightly higher as compared to the recommended world-wide values. The details of the samples preparation procedure and the gamma-ray spectrometry technique are presented, together with the preliminary investigated results of specific activity of naturally occurring radionuclide chains for six representative cement type-analyzed in this current work.

Assessment of Radiological Significance of the Wastes Generated from the Triple Super Phosphate (TSP) Fertilizer Factory, Chittagong, Bangladesh

The activity concentration of 226Ra, 232Th and 40K was determined in solid and liquid samples collected from the TSP Fertilizer Factory, Chittagong, Bangladesh. A total of 18 samples of seven different kinds (including liquid and solid wastes) were collected and analyzed by gamma ray spectrometry technique using a high purity germanium (HPGe) detector of 40% relative efficiency. The analysis of the liquid waste samples showed that the average activity concentrations of 226Ra and 232Th were 6.26 ± 0.63 and 10.01 ± 1.39 Bq/L, respectively and no 40K was detected in any of the liquid samples. In the solid waste samples the average value of activity concentrations of 226Ra, 232Th and 40K were 187.49 ± 4.88, 70.06 ± 11.76 and 655.94 ± 110.24 Bq/kg, respectively. Considering the stored wastes as a part of the ambient environment of the factory, radium equivalent activity, radiation hazard index and external annual effective dose to the worker and public due to these wastes were also calculated and compared with world average values. DOI: http://dx.doi.org/10.3329/jbas.v36i1.10923 Journal of Bangladesh Academy of Sciences, Vol. 36, No. 1, 79-88, 2012

Natural radioactivity levels (K, Th and Ra) in some areas of Punjab, India

Radioactivity, natural and man-made, is omnipresent in the earth's crust in different amounts. Natural radioactive materials under certain conditions can reach hazardous radiological levels. So, it becomes necessary to study the natural radioactivity levels in soil to assess the dose for the population in order to know the health risks and to have a baseline for future changes in the environmental radioactivity due to human activities. 226Ra, 232Th and 40K analysis has been carried out in soil samples collected from some areas of Punjab, India using gamma-ray spectrometry. Phe technique of gamma ray spectrometry was applied using high purity germanium gamma-ray detector and a PC based MCA. Radium equivalent activities are calculated for the analyzed samples to assess radiation hazards arising due to the use of these soil samples in construction of dwellings. Phe measured activity in the soil ranges from 23.17 to 57.87 Bq kg−1, 59.03 to 160.40 Bq kg−1 and 228.06 to 501.03 Bq kg−1 for 226Ra, 232Ph and 40K with mean values of 37.93, 84.47 and 351.17Bqkg−1 respectively. It has been observed that on the average the outdoor terrestrial gamma air absorbed dose rate is about 84.65nGyh−1.

A Study on the Radioactivity Level in Raw Materials, Final Products and Wastes of the Phosphate Fertilizer Industries in Bangladesh

A study on the detection of probable radionuclides and their activity concentrations in the raw material (phosphate rock), final product (fertilizer) and waste samples collected from all the phosphate fertilizer factories (total two factories—A Diammonium Phosphate, DAP and a Triple Super Phosphate, TSP factory) in Bangladesh were carried out. A total of seven types of samples (grossly divided into solid and liquid types); liquid waste, waste-mixed river water, normal river water, phosphate rock, phosphate fertilizer, solid waste and normal soil; were analyzed under this study. Raw material samples were collected only from the TSP fertilizer factory. Fertilizer, solid and liquid waste samples were collected from both the factories under study. Moreover, normal soil and natural surface water samples from the suitable areas adjacent to the factories were also collected for the comparison purpose. The samples were analyzed by gamma ray spectrometry technique using a Hyper-Pure Germanium (HPGe) detector of 40% relative efficiency. The analysis of the samples showed that only natural radionuclides such as 226Ra, 232Th and 40K were present in the samples and no traces of artificial radioactivity were found in any of the samples. 40K was found below the detection limit in some samples. The analysis of the samples in the case of TSP fertilizer factory showed that the average activity concentrations of 226Ra and 232Th and 40K in raw materials were 851.27 ± 7.10, 19.63 ± 6.57 and 54.06 ± 5.93 Bq/kg, respectively, in final product 211.90 ± 4.74, 42.48 ± 10.56 Bq/kg and ND (Not Detected), respectively, in solid waste 187.49 ± 4.88, 70.06 ± 11.76 and 289.27 ± 40.24 Bq/kg, respectively and in liquid waste 6.26 ± 0.63, 10.01 ± 1.39 Bq/L and ND, respectively. The measured results in the case of samples collected from DAP fertilizer factory showed that the average activity concentrations of 226Ra and 232Th and 40K in the final product were 17.31 ± 3.92, 69.74 ± 9.88 and 48.46 ± 17.22 Bq/kg, respectively, in solid waste 24.47 ± 4.15, 164.62 ± 11.08, 191.52 ± 33.74 Bq/kg, respectively and in liquid waste 3.59 ± 1.05, 37.08 ± 3.30 Bq/L and ND, respectively. Considering the stored raw materials and wastes the part of the ambient environment of the factory, radium equivalent activity, radiation hazard index and external annual effective dose to the workers and public due to these materials were also calculated and compared with world average values.

Beta Decay Studies of Neutron Rich Nuclei Using Total Absorption Gamma-ray Spectroscopy and Delayed Neutron Measurements

A complete characterisation of the β-decay of neutron-rich nuclei can be obtained from the measurement of β -delayed gamma rays and, whenever the process is energetically possible, β -delayed neutrons. The accurate determination of the β-intensity distribution and the β -delayed neutron emission probability is of great relevance in the elds of reactor technology and nuclear astrophysics. A programme for combined measurements using the total absorption gamma-ray spectroscopy technique and both neutron counters and neutron time-of-flight spectrometers is presented.

Assessment of the radiological hazards of sand sediments collected from streams and streamlets of the uranium deposit areas in West Khasi Hills District, Meghalaya, India

Primordial radionuclides in sand sediments that are often used as constructing materials are one of the sources of radiation hazard in dwellings. Activity concentrations of the primordial radionuclides of 40K, 226Ra and 232Th have been measured in sand sediments collected from streams and streamlets lying within and around the uranium mineralization deposit blocks of Kylleng-Pyndensohiong, Mawthabah Areas of West Khasi Hills District, Meghalaya, India. The technique of gamma-ray spectroscopy using a NaI(Tl) detector with a PC-based multi channel analyser was applied for determination of the activity concentrations. The activity of the sand sediments obtained in this study ranges from 95.3 to 1,088.8 Bq kg−1 for 40K; 38.3 to 784.1 Bq kg−1 for 226Ra and 78.0 to 316.1 Bq kg−1 for 232Th. Sand sediments from two sampling locations lying within the mineralization zone show highest concentrations of these radionuclides. The radiological hazards of the sand sediments were calculated using various models given in the literature. The radium equivalent activity was found to be higher than the accepted standard criterion value of 370 Bq kg−1 and the values of external and internal hazard indices were also found to be higher than unity in these two sampling locations. Besides these two sampling locations, a sampling location lying at a nearby distance from the mineralization zone also exhibits hazard indices values greater than unity.

Erratum to “Applicability study of using in-situ gamma ray spectrometry technique for 137Cs and 210Pbex inventories measurement in grassland environments” [Applied Radiation and Isotopes 68 (2010), 1143–1149

Erratum to “Applicability study of using in-situ gamma ray spectrometry technique for 137Cs and 210Pbex inventories measurement in grassland environments” [Applied Radiation and Isotopes 68 (2010), 1143–1149

Radiological hazards of TENORM in precipitated calcium carbonate generated as waste at nitrophosphate fertilizer plant in Pakistan

The NORM (naturally occurring radioactive material) in phosphate rock is transferred as TENORM (technologically enhanced naturally occurring radioactive material) to phosphatic fertilizers and to the waste generated by the chemical processes. The waste generated at the NP (nitrophosphate) fertilizer plant at Multan in Pakistan is PCC (precipitated calcium carbonate). Thirty samples of the PCC were collected from the heaps of the waste near the fertilizer plant. Activity concentrations of radionuclides in the waste samples were measured by using the technique of gamma ray spectrometry consisting of coaxial type HPGe (high purity germanium) detector coupled with a PC (personal computer) based MCA (multichannel analyzer) through a spectroscopy amplifier. Activity concentrations of 226Ra, 232Th and 40K in the waste samples were determined to be 273 ± 23 (173–398), 32 ± 4 (26–39) and 56 ± 5 (46–66) Bq kg −1 respectively. The activity concentration of 226Ra in the PCC waste was found to be higher than that in naturally occurring calcium carbonate (limestone and marble) and in worldwide soil. Radiological hazard was estimated from indoor and outdoor exposure to gamma rays from the PCC. Indoor annual effective dose was higher than 1 m Sv. Potential radiological pollution in the environment from TENORM in the PCC has also been addressed.

Cancer Risk in Pakistan Due to Natural Environmental Pollutants

Wheat is a staple food in Pakistan. Production of wheat is increased with extensive use of phosphate based fertilizers in agricultural fields. Activity mass concentration of primordial radionuclides due to use of phosphate fertilizers in soil enhances the external gamma dose and due to the consumption of wheat food grown on these soils also increases the internal dose. Different types of soil, including saline and normal soil in the districts of Lahore and Faisalabad in Punjab were selected for this study. The technique of gamma ray spectroscopy was used for the determination of s levels of radioactivity 226Ra, 232Th, 40K, and the nuclear fallout 137Cs in soil, wheat and wheat made products. Radioactivity in flour, chapatti, bread, nan and rusk was determined. Maximum activity was found in the chapatti sample of highly fertilized soil. Calculations were made for the determination of external absorbed dose in air from soil and internal absorbed dose in human body due to the consumption of wheat and wheat products. The average value of wheat consumption of 140 kg was used in the estimation of ingestion dose. The value of the ingestion dose due to highly fertilized soil was 206.1 μSv/Yr, while the total ingestion dose due to unfertilized farm’s food was 146.3 μSv/Yr. Risk assessment to man due to ingestion of wheat was also calculated. The cancer risk assessment due to ingestion of wheat food grown on highly fertilized soils comes as additional sufferings of 14 persons in cancer per million.

Radioactivity measurement in the granites of North Karnataka, India and its radiological implications

The natural radioactivities due to uranium, thorium and potassium in granite samples contribute to the radiation dose received by human beings significantly. It is essential to evaluate the activity levels of these nuclides for the assessment of natural radiation dose. The natural radioactivity levels of some granite samples collected from different quarries of North Karnataka, India are estimated using high-resolution gamma ray spectrometry technique and the results are reported in this paper.

Natural radionuclide content and radiological hazard associated with usage of quartzite sand samples from Ovacik-Silifke-Mersin open pit as building material in Turkey

Activity concentrations of (238)U, (232)Th, (226)Ra and (40)K in quartzite sand samples collected from the Ovacik-Silifke-Mersin open pit located in the East Mediterranean region of Turkey were determined by using a gamma-ray spectrometry technique. The mean activity concentrations of the (238)U, (232)Th, (226)Ra and (40)K in quartzite sand samples were found as 81.7 +/- 22.9 Bq kg(-1), 6.3 +/- 2.8 Bq kg(-1), 77.5 +/- 24.3 Bq kg(-1)and 140.0 +/- 124.1 Bq kg(-1), respectively. The gamma index (I(gamma)), the internal exposure index (I(alpha)), the indoor absorbed dose rate (D(in)) and the corresponding annual effective dose (H(in)) were evaluated for the public exposure to radiological hazard arising due to the use of quartzite sand samples as building material. The values of I(gamma), I(alpha), D(in) and H(in) ranged from 0.20 to 0.75, with a mean of 0.34 +/- 0.11, 0.23 to 0.77 with a mean of 0.39 +/- 0.12, 58.27 to 201.51 nGy h(-1) with a mean of 93.33 +/- 27.63 nGy h(-1) and 0.29 to 0.99 mSv with a mean of 0.46 +/- 0.14 mSv, respectively.

γ-Ray Spectroscopy at the Limits: First Observation of Rotational Bands inLr255

The rotational band structure of 255Lr has been investigated using advanced in-beam gamma-ray spectroscopic techniques. To date, 255Lr is the heaviest nucleus to be studied in this manner. One rotational band has been unambiguously observed and strong evidence for a second rotational structure was found. The structures are tentatively assigned to be based on the 1/2-[521] and 7/2-[514] Nilsson states, consistent with assignments from recently obtained alpha decay data. The experimental rotational band dynamic moment of inertia is used to test self-consistent mean-field calculations using the Skyrme SLy4 interaction and a density-dependent pairing force.

Absolute determination of soluble potassium in tea infusion by gamma-ray spectroscopy

Abstract Potassium content in tea brew was determined by gamma-ray spectroscopy, using the 1461 keV gamma-ray from 40K, the naturally occurring radioactive isotope of potassium. We measured radiation with a shielded HPGe detector from individual test samples of tea leaves, before and after infusion preparation, and from commercial instant tea powder. The correction factor for the gamma-ray self-absorption in the extended source was determined with the help of Monte-Carlo simulations. This gamma-ray spectroscopy technique enabled the absolute determination of potassium content with a relative uncertainty smaller than 4%, at the one standard deviation confidence level, showing the feasibility of this method. An experiment to evaluate a possible systematic uncertainty due to K distribution heterogeneity in the sample was performed, with the result that the corresponding relative standard deviation is smaller than 2% at 95% confidence level.

Trace element concentrations in sediments from Kadavu passage, Fiji

Grab sediments, collected from 11 locations from the Pacific Ocean floor in the region between Suva Peninsula and Kadavu Island, Fiji, were investigated for concentrations of 20 elements using neutron activation and high-resolution gamma ray spectroscopy techniques. The sediments were collected at distances between 5-35 km from the mainland and at ocean depths ranging from 500 to 2000 m. A comparison of the elemental abundances of these sediments with those of the Suva lagoon and other nearby locations indicates that the ocean sediments are likely to be derived from sediments washed out to sea from the mainland. The sediments also show no evidence of any metal contamination from the industrial activity in the Suva metropolitan area.

Role of activation analysis for radiation control in accelerator facilities

Activation is one of the severe problems at the high-energy accelerator facilities. By using gamma-ray spectrometry and activation detector technique, we could obtain important information on (1) nuclear reactions, (2) energy spectra of secondary particles, (3) penetration behavior of secondary particles in shield wall, (4) historical record of beam loss occurred in the accelerator rooms. It was concluded that the technique and knowledge of activation analysis are very useful to solve the radiation protection problems at the accelerator facilities.

Natural radioactivity hazards of building bricks fabricated from saline soil of two districtsof Pakistan

Primordial radionuclides in building materials are one of the sources of radiation hazard indwellings made of those materials. Activity concentrations of primordial radionuclides40K,226Ra and 232Th have been measured in house building bricks fabricated from saline soil. Forty samples ofthe bricks were collected from the brick fabrication sites and brick baking kilns in andaround the saline soil areas of the districts of Lahore and Faisalabad in the Punjabprovince of Pakistan. The technique of gamma-ray spectroscopy using an HPGedetector with a PC-based multi-channel analyser was applied for determination ofactivity concentrations in the brick samples. The activity mass concentrations of40K,226Ra and 232Th measured in the brick samples were respectively567.7 ± 38.3 (493–631),28.4 ± 3.8 (23–35),and 56.0 ± 4.6 (46–65) Bq kg−1. The radiological hazards of the bricks were calculated using various models given in theliterature. The radium equivalent activity was less than the accepted standard criterion value of370 Bq kg−1 and the values of other hazard indices were also below their limit values. The radiologicalhazard parameters of the bricks under investigation have been compared with thosefrom other locations of Pakistan and also from some other countries in Asia.

Low-spin states in 182Os and Kπ = 0+, 2+ excited bands

Excited states in 182Os were populated by the β+/EC decay of 182Ir following mass separation. Gamma-ray and conversion electron spectroscopy techniques were employed. Monopole (E0) contributions were determined in transitions populating the ground-state band. A systematic study of the low-spin structures in the Os isotopes is presented and a detailed analysis in the framework of a microscopic configuration mixing approach is performed.

Characterization of aerosols generated in a steel processing factory

The levels of total suspended particulates (TSP) within the complex of a steel factory (Fletcher Pacific Steel Fiji) have been investigated through high volume air sampling. The levels of TSP inside and outside (in the ambient environment) the factory has been found to be in the range of 121-339 and 33-80 μg m-3 respectively. The levels inside the factory exceed the WHO guideline by a factor of 2-4. The management of the factory was very proactive to determine the air quality for records and to safeguard the health and safety of all the employees, contractors, and visitors. At the request of the factory, the exposed filters were analysed by neutron activation and gamma-ray spectroscopy techniques and the results are presented.