Applied Radiation and Isotopes最新文献_第4页

Sensitivity gains and quality control in radioxenon monitoring via laboratory Re-measurements 实验室重测法监测放射性氙的灵敏度增益和质量控制

IF 1.8 3区工程技术 Q3 CHEMISTRY, INORGANIC & NUCLEAR

Applied Radiation and Isotopes

Pub Date : 2026-01-14 DOI: 10.1016/j.apradiso.2026.112427

Mattias Aldener, Tomas Fritioff, Catharina Söderström

As a part of the Comprehensive Nuclear Test Ban Treaty (CTBT) the International Monitoring System (IMS), to monitor the compliance of member states to CTBT, is currently being established. The IMS consists of different monitoring techniques, of which the sampling and detection of radioactive noble gases, mainly radioxenon, is one. As a complement to the monitoring stations, a number of radionuclide laboratories are included in the IMS. Samples collected at a station can be sent to a laboratory for further analysis. However, due to the short half-lives of radioxenon isotopes, the benefits of conducting re-measurements in the laboratory are unclear, as the isotope may decay significantly during transport.

The FOI facilities in Sweden host a SAUNA III IMS system and a radioxenon laboratory. The laboratory is equipped with a SAUNA Laboratory system for re-analysis of xenon samples collected using the IMS systems. To investigate both the advantages and limitations of laboratory re-measurements, several radioxenon samples from the IMS station are re-measured at the laboratory system, and compared to the SAUNA III results.

This work shows that, in addition to ensuring quality control of the sampling and xenon purification process, laboratory re-measurements also provide a better detectability for most of the radioxenon isotopes. For ¹³³Xe and ^131mXe the detectability at the laboratory is as good as at the IMS station up to at least a week after the collection period, and can be improved further by increasing the measurement time at the laboratory. The higher sensitivity at the laboratory measurements also results in a better estimation of the isotopic ratios, which is important for classification of the detection.

作为《全面禁止核试验条约》的一部分，目前正在建立监测成员国遵守《全面禁止核试验条约》情况的国际监测系统。IMS由不同的监测技术组成，其中对放射性惰性气体（主要是放射性氙）的采样和检测是一种。作为对监测站的补充，一些放射性核素实验室被列入监测系统。在站点收集的样本可以送到实验室进行进一步分析。然而，由于放射性氙同位素的半衰期很短，在实验室进行重新测量的好处尚不清楚，因为同位素可能在运输过程中显著衰减。瑞典的FOI设施拥有一个桑拿III IMS系统和一个放射性氙实验室。该实验室配备了桑拿实验室系统，用于重新分析使用IMS系统收集的氙气样品。为了研究实验室重测的优点和局限性，在实验室系统中对IMS站的几个放射性氙样品进行了重测，并与桑拿III的结果进行了比较。这项工作表明，除了确保采样和氙净化过程的质量控制外，实验室重新测量也为大多数放射性氙同位素提供了更好的可探测性。对于133Xe和131mXe，在实验室的可探测性至少在采集期后一周内与IMS站一样好，并且可以通过增加实验室的测量时间进一步提高。实验室测量的高灵敏度也导致对同位素比率的更好估计，这对检测的分类很重要。

{"title":"Sensitivity gains and quality control in radioxenon monitoring via laboratory Re-measurements","authors":"Mattias Aldener, Tomas Fritioff, Catharina Söderström","doi":"10.1016/j.apradiso.2026.112427","DOIUrl":"10.1016/j.apradiso.2026.112427","url":null,"abstract":"<div><div>As a part of the Comprehensive Nuclear Test Ban Treaty (CTBT) the International Monitoring System (IMS), to monitor the compliance of member states to CTBT, is currently being established. The IMS consists of different monitoring techniques, of which the sampling and detection of radioactive noble gases, mainly radioxenon, is one. As a complement to the monitoring stations, a number of radionuclide laboratories are included in the IMS. Samples collected at a station can be sent to a laboratory for further analysis. However, due to the short half-lives of radioxenon isotopes, the benefits of conducting re-measurements in the laboratory are unclear, as the isotope may decay significantly during transport.</div><div>The FOI facilities in Sweden host a SAUNA III IMS system and a radioxenon laboratory. The laboratory is equipped with a SAUNA Laboratory system for re-analysis of xenon samples collected using the IMS systems. To investigate both the advantages and limitations of laboratory re-measurements, several radioxenon samples from the IMS station are re-measured at the laboratory system, and compared to the SAUNA III results.</div><div>This work shows that, in addition to ensuring quality control of the sampling and xenon purification process, laboratory re-measurements also provide a better detectability for most of the radioxenon isotopes. For <sup>133</sup>Xe and <sup>131m</sup>Xe the detectability at the laboratory is as good as at the IMS station up to at least a week after the collection period, and can be improved further by increasing the measurement time at the laboratory. The higher sensitivity at the laboratory measurements also results in a better estimation of the isotopic ratios, which is important for classification of the detection.</div></div>","PeriodicalId":8096,"journal":{"name":"Applied Radiation and Isotopes","volume":"229 ","pages":"Article 112427"},"PeriodicalIF":1.8,"publicationDate":"2026-01-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145973057","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Monte Carlo sensitivity analysis of the Vinten 671 ionization chamber activity calibration coefficients Vinten 671电离室活度标定系数的蒙特卡罗灵敏度分析

IF 1.8 3区工程技术 Q3 CHEMISTRY, INORGANIC & NUCLEAR

Applied Radiation and Isotopes

Pub Date : 2026-01-14 DOI: 10.1016/j.apradiso.2026.112437

A. Bourgouin, R.W. Townson, R. Galea

Accurate calibration coefficients (CCs) are essential for radionuclide calibrators employed in nuclear medicine and radiopharmacy applications. These coefficients depend on multiple experimental and modelling parameters, including sample composition, geometry, and positioning within the ionization chamber (IC). This work investigates the sensitivity of CCs for the National Physical Laboratory (NPL) Vinten 671 well-type IC, whose design is represented in the widely used NPL Fidelis calibrator. A comprehensive sensitivity analysis was conducted using the EGSnrc Monte Carlo (MC) model to evaluate the impact of both physical and computational parameters on CC determination. Variables examined included detector and vial geometry, nuclear decay data libraries, and simulation energy cut-off values.

The results demonstrate that CCs are largely stable under minor variations in vial volume and vertical positioning but exhibit notable sensitivity to the nuclear data selection and the aluminium inner wall thickness of the chamber. Accurate modelling of the vial and holder, particularly in the axial plane, is crucial. Parameters such as nitrogen pressure and aluminium wall thickness, even with minimal changes, demonstrate a significant impact, with optimization offering potential improvements in agreement between experimental and simulated values. Future efforts should refine the EGSnrc model, with experimental validation enhancing model reliability.

准确的校准系数（CCs）对于核医学和放射药学应用中使用的放射性核素校准器至关重要。这些系数取决于多个实验和建模参数，包括样品组成、几何形状和电离室（IC）内的位置。这项工作研究了国家物理实验室（NPL） Vinten 671井型集成电路的CCs灵敏度，其设计在广泛使用的NPL Fidelis校准器中得到了体现。采用EGSnrc蒙特卡罗（MC）模型进行综合敏感性分析，以评估物理参数和计算参数对CC测定的影响。检查的变量包括探测器和小瓶几何形状、核衰变数据库和模拟能量截止值。结果表明，在小瓶体积和垂直位置的微小变化下，CCs基本稳定，但对核数据选择和腔室铝内壁厚度表现出显著的敏感性。准确建模的小瓶和持有人，特别是在轴向平面，是至关重要的。氮压力和铝壁厚度等参数即使变化很小，也会产生重大影响，优化后的实验值和模拟值之间的一致性可能得到改善。未来的工作应该完善EGSnrc模型，通过实验验证来提高模型的可靠性。

{"title":"Monte Carlo sensitivity analysis of the Vinten 671 ionization chamber activity calibration coefficients","authors":"A. Bourgouin, R.W. Townson, R. Galea","doi":"10.1016/j.apradiso.2026.112437","DOIUrl":"10.1016/j.apradiso.2026.112437","url":null,"abstract":"<div><div>Accurate calibration coefficients (CCs) are essential for radionuclide calibrators employed in nuclear medicine and radiopharmacy applications. These coefficients depend on multiple experimental and modelling parameters, including sample composition, geometry, and positioning within the ionization chamber (IC). This work investigates the sensitivity of CCs for the National Physical Laboratory (NPL) Vinten 671 well-type IC, whose design is represented in the widely used NPL Fidelis calibrator. A comprehensive sensitivity analysis was conducted using the EGSnrc Monte Carlo (MC) model to evaluate the impact of both physical and computational parameters on CC determination. Variables examined included detector and vial geometry, nuclear decay data libraries, and simulation energy cut-off values.</div><div>The results demonstrate that CCs are largely stable under minor variations in vial volume and vertical positioning but exhibit notable sensitivity to the nuclear data selection and the aluminium inner wall thickness of the chamber. Accurate modelling of the vial and holder, particularly in the axial plane, is crucial. Parameters such as nitrogen pressure and aluminium wall thickness, even with minimal changes, demonstrate a significant impact, with optimization offering potential improvements in agreement between experimental and simulated values. Future efforts should refine the EGSnrc model, with experimental validation enhancing model reliability.</div></div>","PeriodicalId":8096,"journal":{"name":"Applied Radiation and Isotopes","volume":"229 ","pages":"Article 112437"},"PeriodicalIF":1.8,"publicationDate":"2026-01-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145973123","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Impact of arc therapy in boron neutron capture therapy (BNCT) on dose uniformity and motion robustness 硼中子俘获治疗中电弧治疗对剂量均匀性和运动稳健性的影响

IF 1.8 3区工程技术 Q3 CHEMISTRY, INORGANIC & NUCLEAR

Applied Radiation and Isotopes

Pub Date : 2026-01-13 DOI: 10.1016/j.apradiso.2026.112439

Junyan Wang , Haiyun Kong , Wangxuan Li , Deming Li

Monte Carlo simulations were conducted to evaluate the dose distribution characteristics and motion robustness of fixed-angle versus arc irradiation techniques in boron neutron capture therapy (BNCT), using a head phantom. For fixed-angle irradiation, an anterior-posterior (AP) beam was oriented towards the facial plane. In contrast, the arc technique involved a continuous 180° rotation, from the left to the right, around the central axis traversing the face. The target was located in the nasal cavity region. Results demonstrated the dosimetric superiority of the arc technique, which increased the mean tumor dose by 0.7 Gy-Eq and improved the dose homogeneity index from 0.67 to 0.74. For the head phantom in this study, the arc technique showed enhanced motion robustness, reducing dose deviations across five critical motion directions including anterior translation (AT), left translation (LT), right translation (RT), inferior rotation (IR), and superior rotation (SR). The maximum improvement was a 15.3 % reduction in the E2 % metric (dose error for the 2 % volume after motion-induced perturbations) at the RT direction. The largest average dose error reduction was achieved in the AT direction, reaching 8.2 %. These findings confirm that arc irradiation confers distinct advantages in BNCT cases affected by motion errors, owing to its superior dose conformity and stability.

采用蒙特卡罗模拟方法，对硼中子俘获治疗（BNCT）中固定角度与电弧照射技术的剂量分布特性和运动鲁棒性进行了评估。对于固定角度照射，前后（AP）束朝向面平面。相比之下，圆弧技术涉及一个连续的180°旋转，从左到右，围绕中心轴穿过脸。目标位于鼻腔区域。结果表明，弧技术的剂量学优势，使平均肿瘤剂量增加0.7 Gy-Eq，剂量均匀性指数从0.67提高到0.74。对于本研究中的头部幻像，弧技术显示出增强的运动稳健性，减少了五个关键运动方向上的剂量偏差，包括前平移（AT）、左平移（LT）、右平移（RT）、下旋转（IR）和上旋转（SR）。最大的改善是在RT方向上E2 %度量（运动引起的扰动后2%体积的剂量误差）减少15.3%。AT方向的平均剂量误差减小幅度最大，达到8.2%。这些发现证实了电弧照射在受运动误差影响的BNCT病例中具有明显的优势，因为它具有优越的剂量一致性和稳定性。

{"title":"Impact of arc therapy in boron neutron capture therapy (BNCT) on dose uniformity and motion robustness","authors":"Junyan Wang , Haiyun Kong , Wangxuan Li , Deming Li","doi":"10.1016/j.apradiso.2026.112439","DOIUrl":"10.1016/j.apradiso.2026.112439","url":null,"abstract":"<div><div>Monte Carlo simulations were conducted to evaluate the dose distribution characteristics and motion robustness of fixed-angle versus arc irradiation techniques in boron neutron capture therapy (BNCT), using a head phantom. For fixed-angle irradiation, an anterior-posterior (AP) beam was oriented towards the facial plane. In contrast, the arc technique involved a continuous 180° rotation, from the left to the right, around the central axis traversing the face. The target was located in the nasal cavity region. Results demonstrated the dosimetric superiority of the arc technique, which increased the mean tumor dose by 0.7 Gy-Eq and improved the dose homogeneity index from 0.67 to 0.74. For the head phantom in this study, the arc technique showed enhanced motion robustness, reducing dose deviations across five critical motion directions including anterior translation (AT), left translation (LT), right translation (RT), inferior rotation (IR), and superior rotation (SR). The maximum improvement was a 15.3 % reduction in the E2 % metric (dose error for the 2 % volume after motion-induced perturbations) at the RT direction. The largest average dose error reduction was achieved in the AT direction, reaching 8.2 %. These findings confirm that arc irradiation confers distinct advantages in BNCT cases affected by motion errors, owing to its superior dose conformity and stability.</div></div>","PeriodicalId":8096,"journal":{"name":"Applied Radiation and Isotopes","volume":"229 ","pages":"Article 112439"},"PeriodicalIF":1.8,"publicationDate":"2026-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145973122","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

The EURAMET.RI(II)-S9 interlaboratory comparison of the radionuclide calibrators EURAMET。RI(II)-S9放射性核素校准器的实验室间比较

IF 1.8 3区工程技术 Q3 CHEMISTRY, INORGANIC & NUCLEAR

Applied Radiation and Isotopes

Pub Date : 2026-01-13 DOI: 10.1016/j.apradiso.2026.112434

Arūnas Gudelis , Andrei Antohe , Eszter Bodnár , Robert Bretner-Messler , Pavel Dryák , Andrej Javorník , Kristyna Kohoutova , Petr Kovář , Matej Krivošík , Ioana Lalau , Patrick Lobner , Liviu-Cristian Mihailescu , Anita Peka , Miguel Roteta , Jan Rusnák , Vladimír Sochor , Jana Sochorová , Jiri Šuráň , Laszlo Szücs , Isabelle Taschwer , Martin Volesak

At EURAMET TC-IR meeting in Madrid, March 1, 2023, it was proposed to organize a comparison on radionuclide calibrators to measure the activity of short-lived radionuclides used in nuclear medicine: F-18, Ga-67, Y-90, Tc-99 m, In-111, I-123, I-131, Sm-153, Lu-177 and Tl-201. The technical protocol was elaborated in June 2023 and after comments received from CCRI(II) and KCWG (II) it was finally approved in August 2023.

The comparison took place in Prague at CMI headquarters 11–15 September 2023.

Original solutions provided by manufacturers were used to prepare working solutions with which 2 mL ampoules, 5 mL ampoules, P6 vials, and Schott 10 R type1+ vials were filled. For control measurements by the gamma-ray spectrometry with a HPGe detector, samples were prepared using the same solution. For radionuclides Ga-67, Sm-153, and Lu-177, special solutions were produced, and 3.6 mL ampoules required by SIR were filled. Activity values were determined gravimetrically from activity concentration values measured by the primary method.

The comparison reference values were determined from activity measurement results of a selection of participants by using the Power Moderated Mean approach.

2023年3月1日在马德里举行的EURAMET TC-IR会议上，提议组织对放射性核素校准器进行比较，以测量核医学中使用的短寿命放射性核素：F-18、fa -67、Y-90、Tc-99 m、in -111、I-123、I-131、Sm-153、Lu-177和Tl-201的活度。技术协议在2023年6月详细阐述，在收到CCRI（II）和KCWG （II）的意见后，最终于2023年8月获得批准。比较于2023年9月11日至15日在布拉格CMI总部进行。使用制造商提供的原始溶液配制工作溶液，分别装2ml安瓿、5ml安瓿、P6瓶和Schott 10r type1+瓶。对于使用HPGe探测器的伽马射线能谱法进行的对照测量，样品使用相同的溶液制备。对于放射性核素Ga-67、Sm-153和Lu-177，制作特殊溶液，并填充SIR所需的3.6 mL安瓿。活性值由原方法测得的活性浓度值用重量法测定。比较参考值是通过使用功率调节平均方法从选定的参与者的活动测量结果确定的。

{"title":"The EURAMET.RI(II)-S9 interlaboratory comparison of the radionuclide calibrators","authors":"Arūnas Gudelis , Andrei Antohe , Eszter Bodnár , Robert Bretner-Messler , Pavel Dryák , Andrej Javorník , Kristyna Kohoutova , Petr Kovář , Matej Krivošík , Ioana Lalau , Patrick Lobner , Liviu-Cristian Mihailescu , Anita Peka , Miguel Roteta , Jan Rusnák , Vladimír Sochor , Jana Sochorová , Jiri Šuráň , Laszlo Szücs , Isabelle Taschwer , Martin Volesak","doi":"10.1016/j.apradiso.2026.112434","DOIUrl":"10.1016/j.apradiso.2026.112434","url":null,"abstract":"<div><div>At EURAMET TC-IR meeting in Madrid, March 1, 2023, it was proposed to organize a comparison on radionuclide calibrators to measure the activity of short-lived radionuclides used in nuclear medicine: F-18, Ga-67, Y-90, Tc-99 m, In-111, I-123, I-131, Sm-153, Lu-177 and Tl-201. The technical protocol was elaborated in June 2023 and after comments received from CCRI(II) and KCWG (II) it was finally approved in August 2023.</div><div>The comparison took place in Prague at CMI headquarters 11–15 September 2023.</div><div>Original solutions provided by manufacturers were used to prepare working solutions with which 2 mL ampoules, 5 mL ampoules, P6 vials, and Schott 10 R type1+ vials were filled. For control measurements by the gamma-ray spectrometry with a HPGe detector, samples were prepared using the same solution. For radionuclides Ga-67, Sm-153, and Lu-177, special solutions were produced, and 3.6 mL ampoules required by SIR were filled. Activity values were determined gravimetrically from activity concentration values measured by the primary method.</div><div>The comparison reference values were determined from activity measurement results of a selection of participants by using the Power Moderated Mean approach.</div></div>","PeriodicalId":8096,"journal":{"name":"Applied Radiation and Isotopes","volume":"230 ","pages":"Article 112434"},"PeriodicalIF":1.8,"publicationDate":"2026-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145976379","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Isotopic exchange of tritium (3H) and 14C in gas/liquid systems 气/液体系中氚（3H）和14C的同位素交换

IF 1.8 3区工程技术 Q3 CHEMISTRY, INORGANIC & NUCLEAR

Applied Radiation and Isotopes

Pub Date : 2026-01-13 DOI: 10.1016/j.apradiso.2026.112428

Øyvind Dugstad , Tor Bjørnstad

The application of tracers to follow the flow of injected fluids (water or gas) in petroleum and geothermal reservoirs have shown to be highly successful. Direction of flow, flow velocities, sweep efficiency and, for geothermal reservoirs, the effectiveness of heat extraction are monitored. Some of the applicable tracers are also radiolabeled, for instance with tritium (³H or T) and/or ¹⁴C. So-called conservative tracers (not degraded by environmental factors) are required. The most trustworthy conservative tracer compounds are those consisting of a molecule of the traced phase where one of the atoms has been exchanged with a radioactive isotope of the same element. Examples are HTO for water and CH₃T or CH₃CH₂T for lean hydrocarbon gas. Also, the radionuclide ¹⁴C can be used by exchange with natural non-radioactive carbon isotopes. Such a tracer compounds are called intrinsic radiotracers.

However, during contact of such compounds with reservoir fluids one mechanism which may contribute to loss of tracer is the exchange of the radioactive label (T or ¹⁴C) with non-radioactive hydrogen and carbon isotopes in the reservoir fluids. This process is called isotope exchange and may be composed of several mechanisms. The aim of the present study has been limited to examine the potential for isotopic exchange, as a sink mechanism, for the gases tritiated and ¹⁴C-labelled methane and ethane to water and oil in petroleum reservoirs. The highest exchange rate found is 3,2 % of tritium from radiolabeled ethane to water at 150 °C after 6 months. All factors evaluated, this level of exchange is judged acceptable for the labelled compounds to be considered as conservative tracers for gas injection in oil reservoirs.

示踪剂用于跟踪石油和地热储层中注入流体（水或气）的流动已被证明是非常成功的。对流动方向、流速、波及效率以及地热储层的抽热效果进行了监测。一些适用的示踪剂也进行放射性标记，例如用氚（3H或T）和/或14C。需要所谓的保守示踪剂（不被环境因素降解）。最可靠的保守的示踪化合物是由一个被示踪相的分子组成的，其中一个原子已与同一元素的放射性同位素交换。例如水的HTO和贫烃气的CH3T或CH3CH2T。此外，放射性核素14C可以与天然的非放射性碳同位素交换使用。这种示踪化合物称为本征放射性示踪剂。然而，在这些化合物与储层流体接触时，可能导致示踪剂损失的一种机制是，放射性标号（T或14C）与储层流体中的非放射性氢和碳同位素交换。这个过程称为同位素交换，可能由几种机制组成。本研究的目的仅限于研究同位素交换的潜力，作为一种吸收机制，将氚化和14c标记的甲烷和乙烷气体转化为油藏中的水和油。发现的最高交换率是在6个月后从放射性标记的乙烷到150°C的水中的3.2%的氚。经过所有因素的评估，这种交换水平被认为是可以接受的，标记的化合物被认为是油藏注气的保守示踪剂。

{"title":"Isotopic exchange of tritium (3H) and 14C in gas/liquid systems","authors":"Øyvind Dugstad , Tor Bjørnstad","doi":"10.1016/j.apradiso.2026.112428","DOIUrl":"10.1016/j.apradiso.2026.112428","url":null,"abstract":"<div><div>The application of tracers to follow the flow of injected fluids (water or gas) in petroleum and geothermal reservoirs have shown to be highly successful. Direction of flow, flow velocities, sweep efficiency and, for geothermal reservoirs, the effectiveness of heat extraction are monitored. Some of the applicable tracers are also radiolabeled, for instance with tritium (<sup>3</sup>H or T) and/or <sup>14</sup>C. So-called conservative tracers (not degraded by environmental factors) are required. The most trustworthy conservative tracer compounds are those consisting of a molecule of the traced phase where one of the atoms has been exchanged with a radioactive isotope of the same element. Examples are HTO for water and CH<sub>3</sub>T or CH<sub>3</sub>CH<sub>2</sub>T for lean hydrocarbon gas. Also, the radionuclide <sup>14</sup>C can be used by exchange with natural non-radioactive carbon isotopes. Such a tracer compounds are called intrinsic radiotracers.</div><div>However, during contact of such compounds with reservoir fluids one mechanism which may contribute to loss of tracer is the exchange of the radioactive label (T or <sup>14</sup>C) with non-radioactive hydrogen and carbon isotopes in the reservoir fluids. This process is called isotope exchange and may be composed of several mechanisms. The aim of the present study has been limited to examine the potential for isotopic exchange, as a sink mechanism, for the gases tritiated and <sup>14</sup>C-labelled methane and ethane to water and oil in petroleum reservoirs. The highest exchange rate found is 3,2 % of tritium from radiolabeled ethane to water at 150 °C after 6 months. All factors evaluated, this level of exchange is judged acceptable for the labelled compounds to be considered as conservative tracers for gas injection in oil reservoirs.</div></div>","PeriodicalId":8096,"journal":{"name":"Applied Radiation and Isotopes","volume":"230 ","pages":"Article 112428"},"PeriodicalIF":1.8,"publicationDate":"2026-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146036116","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Theoretical investigation of alternative 177Lu production methods using proton accelerator: A Monte Carlo study 质子加速器制备177Lu替代方法的理论研究：蒙特卡罗研究

IF 1.8 3区工程技术 Q3 CHEMISTRY, INORGANIC & NUCLEAR

Applied Radiation and Isotopes

Pub Date : 2026-01-12 DOI: 10.1016/j.apradiso.2026.112438

Fabian Yoga Prastha , Ahsani Mufidah , Anastasya Jessning Gamalita Mberato , Zaki Su'ud , Imam Kambali

This study presents a theoretical assessment of ¹⁷⁷Lu production using proton accelerator–driven neutron generators with light- and medium-mass target materials. Both the direct route, via neutron activation of ¹⁷⁶Lu, and the indirect route, via activation of ¹⁷⁶Yb, were evaluated for proton energies up to 18 MeV. Monte Carlo simulations with PHITS coupled to DCHAIN were used to model neutron yields, energy spectra, and activation efficiencies for neutron generators composed of H₂¹⁸O, ^natBe, ^natLi, ^natCr, and ^natTi. Results identify ^natBe as the most efficient neutron generator, delivering the highest ¹⁷⁷Lu activities in both production routes. H₂¹⁸O provides superior radionuclidic purity in the direct route due to its moderated neutron spectrum, while ^natTi achieves the highest n.c.a. ¹⁷⁷Lu activity in the indirect route. ^natTi and ^natCr offer intermediate yields with fewer handling hazards. Clinical implementation scenarios indicate that ¹⁷⁷Lu production via the direct route is feasible using ^natBe at 18 MeV for maximum yield (≥500 μA, ≤7 days per patient dose) or H₂¹⁸O at 15 MeV for optimized purity (≥1 mA, ≤10 days per patient dose). While these findings demonstrate the potential of compact, accelerator-driven neutron generator systems as scalable and decentralized alternatives to reactor-based ¹⁷⁷Lu production, further research is required to validate scalability, target thermal management, and economic viability for high-volume clinical deployment.

本研究提出了用质子加速器驱动的中子发生器生产轻、中质量靶材料177Lu的理论评估。通过中子活化176Lu的直接途径和通过活化176Yb的间接途径，质子能量都达到了18 MeV。利用PHITS与DCHAIN耦合的蒙特卡罗模拟，模拟了由H218O、natBe、natLi、natCr和natTi组成的中子发生器的中子产率、能谱和激活效率。结果表明，natBe是最有效的中子发生器，在两种生产路线中都能产生最高的177Lu活性。H218O在直接路径上具有较高的放射性核素纯度，这是由于其中子谱的减速，而natTi在间接路径上具有最高的n.c.a 177Lu活性。natTi和natCr产量适中，处理风险较小。临床实施方案表明，通过直接途径生产177Lu是可行的，使用18mev的natBe获得最大产率（≥500 μA，≤7天/例剂量）或15mev的H218O获得最佳纯度（≥1 mA，≤10天/例剂量）。虽然这些发现证明了紧凑、加速器驱动的中子发生器系统作为基于反应堆的177Lu生产的可扩展和分散替代方案的潜力，但需要进一步的研究来验证可扩展性、目标热管理以及大批量临床部署的经济可行性。

{"title":"Theoretical investigation of alternative 177Lu production methods using proton accelerator: A Monte Carlo study","authors":"Fabian Yoga Prastha , Ahsani Mufidah , Anastasya Jessning Gamalita Mberato , Zaki Su'ud , Imam Kambali","doi":"10.1016/j.apradiso.2026.112438","DOIUrl":"10.1016/j.apradiso.2026.112438","url":null,"abstract":"<div><div>This study presents a theoretical assessment of <sup>177</sup>Lu production using proton accelerator–driven neutron generators with light- and medium-mass target materials. Both the direct route, via neutron activation of <sup>176</sup>Lu, and the indirect route, via activation of <sup>176</sup>Yb, were evaluated for proton energies up to 18 MeV. Monte Carlo simulations with PHITS coupled to DCHAIN were used to model neutron yields, energy spectra, and activation efficiencies for neutron generators composed of H<sub>2</sub><sup>18</sup>O, <sup>nat</sup>Be, <sup>nat</sup>Li, <sup>nat</sup>Cr, and <sup>nat</sup>Ti. Results identify <sup>nat</sup>Be as the most efficient neutron generator, delivering the highest <sup>177</sup>Lu activities in both production routes. H<sub>2</sub><sup>18</sup>O provides superior radionuclidic purity in the direct route due to its moderated neutron spectrum, while <sup>nat</sup>Ti achieves the highest n.c.a. <sup>177</sup>Lu activity in the indirect route. <sup>nat</sup>Ti and <sup>nat</sup>Cr offer intermediate yields with fewer handling hazards. Clinical implementation scenarios indicate that <sup>177</sup>Lu production via the direct route is feasible using <sup>nat</sup>Be at 18 MeV for maximum yield (≥500 μA, ≤7 days per patient dose) or H<sub>2</sub><sup>18</sup>O at 15 MeV for optimized purity (≥1 mA, ≤10 days per patient dose). While these findings demonstrate the potential of compact, accelerator-driven neutron generator systems as scalable and decentralized alternatives to reactor-based <sup>177</sup>Lu production, further research is required to validate scalability, target thermal management, and economic viability for high-volume clinical deployment.</div></div>","PeriodicalId":8096,"journal":{"name":"Applied Radiation and Isotopes","volume":"229 ","pages":"Article 112438"},"PeriodicalIF":1.8,"publicationDate":"2026-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145973124","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A single-moderator neutron spectrometer for neutron spectrum studies in BNCT 用于BNCT中子谱研究的单慢化剂中子星光谱仪

IF 1.8 3区工程技术 Q3 CHEMISTRY, INORGANIC & NUCLEAR

Applied Radiation and Isotopes

Pub Date : 2026-01-12 DOI: 10.1016/j.apradiso.2026.112431

Zhenglin Huang , Liye Liu , Zhihui Tang , Yingjing Wei , Pulin Bai , Jiayu Duan , Bowen Sun

The Single-moderator Neutron Beam Spectrometer (SNBS) based on SiC detector and cylindrical moderator was designed, in which the front surface of SiC detector was covered with LiF coating. A model of the device was established using FLUKA and the response matrix of 100 energy points was calculated. These energy points were uniformly selected in the logarithmic coordinate range of 2 × 10⁻⁹ MeV–20 MeV. At the Radiation Metrology Station of the China Institute of Radiation Protection, a²⁵²Cf neutron source was used for calibration, and the detection efficiency correction coefficients corresponding to each detector were obtained. Subsequently, SNBS was tested at the BSA beam outlet on the CPHS accelerator platform at Tsinghua University. Based on the results, the overall deviation between the measured results and the theoretical calculated values under different measurement conditions was calculated, the maximum measurement relative deviation is less than 10 %. Finally, the proportion of thermal neutrons, epithermal neutrons, and fast neutrons was analyzed. The overall measurement results are basically consistent with the calculated results. SNBS is compact and suitable for measuring high-throughput neutron radiation fields in narrow spaces.

设计了基于SiC探测器和圆柱形慢化剂的单慢化剂中子束光谱仪（SNBS），在SiC探测器前表面覆盖LiF涂层。利用FLUKA建立了该装置的模型，计算了100个能量点的响应矩阵。这些能量点均匀地选择在2 × 10−9 MeV - 20 MeV的对数坐标范围内。在中国辐射防护科学研究院辐射计量站，采用a252Cf中子源进行标定，得到各探测器对应的探测效率校正系数。随后，在清华大学CPHS加速器平台的BSA光束出口对SNBS进行了测试。在此基础上，计算了不同测量条件下的测量结果与理论计算值的总体偏差，最大测量相对偏差小于10%。最后，对热中子、超热中子和快中子的比例进行了分析。总体测量结果与计算结果基本一致。SNBS结构紧凑，适合在狭窄空间内测量高通量中子辐射场。

{"title":"A single-moderator neutron spectrometer for neutron spectrum studies in BNCT","authors":"Zhenglin Huang , Liye Liu , Zhihui Tang , Yingjing Wei , Pulin Bai , Jiayu Duan , Bowen Sun","doi":"10.1016/j.apradiso.2026.112431","DOIUrl":"10.1016/j.apradiso.2026.112431","url":null,"abstract":"<div><div>The Single-moderator Neutron Beam Spectrometer (SNBS) based on SiC detector and cylindrical moderator was designed, in which the front surface of SiC detector was covered with LiF coating. A model of the device was established using FLUKA and the response matrix of 100 energy points was calculated. These energy points were uniformly selected in the logarithmic coordinate range of 2 × 10<sup>−9</sup> MeV–20 MeV. At the Radiation Metrology Station of the China Institute of Radiation Protection, a<sup>252</sup>Cf neutron source was used for calibration, and the detection efficiency correction coefficients corresponding to each detector were obtained. Subsequently, SNBS was tested at the BSA beam outlet on the CPHS accelerator platform at Tsinghua University. Based on the results, the overall deviation between the measured results and the theoretical calculated values under different measurement conditions was calculated, the maximum measurement relative deviation is less than 10 %. Finally, the proportion of thermal neutrons, epithermal neutrons, and fast neutrons was analyzed. The overall measurement results are basically consistent with the calculated results. SNBS is compact and suitable for measuring high-throughput neutron radiation fields in narrow spaces.</div></div>","PeriodicalId":8096,"journal":{"name":"Applied Radiation and Isotopes","volume":"229 ","pages":"Article 112431"},"PeriodicalIF":1.8,"publicationDate":"2026-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145973125","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Standardization of 239Pu using isotopic ratios obtained through alpha spectrometry and mass spectrometry 利用α光谱法和质谱法获得的同位素比值对239Pu进行标准化

IF 1.8 3区工程技术 Q3 CHEMISTRY, INORGANIC & NUCLEAR

Applied Radiation and Isotopes

Pub Date : 2026-01-10 DOI: 10.1016/j.apradiso.2026.112433

A.J. Pearce, M.R. Bodine, R. Collé, R. Essex, J. La Rosa, L. Laureano-Pérez, L. Pibida, M.A. Tyra

The standardization of a new ²³⁹Pu radioactivity solution with considerable impurity was performed. The massic activity of ²³⁹Pu was obtained through 4πα liquid scintillation (LS) counting with correction for significant amounts of other plutonium isotopic impurities made by a combination of isotope dilution alpha spectrometry and isotopic composition measurements by mass spectrometry.

对一种含大量杂质的新型239Pu放射性溶液进行了标准化。239Pu的质量活度是通过4πα液体闪烁（LS）计数得到的，并通过同位素稀释α光谱法和质谱法测量同位素组成的组合对大量其他钚同位素杂质进行了校正。

引用次数: 0

Radiation anomaly detection using continuous wavelet transform and Zernike moments 基于连续小波变换和泽尼克矩的辐射异常检测。

IF 1.8 3区工程技术 Q3 CHEMISTRY, INORGANIC & NUCLEAR

Applied Radiation and Isotopes

Pub Date : 2026-01-10 DOI: 10.1016/j.apradiso.2026.112432

Assem Abdelhakim

Detecting illicit radioactive materials has been always one of the significant tasks for homeland security due to the radiation emissions of such materials that may endanger the citizens. One of the major challenges in radiation detection is to distinguish between normal or background radiation and anomalous source radiation at low source to background radiation ratios. In this paper, an effective anomaly detection method is proposed to detect anomalous Gamma-ray radiation spectra. The method is based on the continuous wavelet transform to exploit the energy-frequency characteristics of the radiation energy spectrum. A Scalogram image is generated from the transform coefficients, where image processing can be applied for extracting effective feature values. The Zernike moments of the Scalogram image are selected to represent the feature vector of the corresponding radiation spectrum. Finally, classification of the given radiation spectrum is carried out using the Mahalanobis distance that represents the anomaly score. The performance is evaluated using real measurements that are collected from a network of radiation detectors. To present the effectiveness of the proposed work, a comparison is conducted with both benchmark and recent methods in terms of the anomaly detection capabilities. Experimental results show that the proposed method achieves better performance compared to the other methods even at low source to background radiation ratios.

由于非法放射性物质的辐射排放可能对公民造成危害，因此检测非法放射性物质一直是国土安全的重要任务之一。辐射探测的主要挑战之一是在低源本底辐射比下区分正常或本底辐射和异常源辐射。本文提出了一种有效的伽玛射线辐射谱异常检测方法。该方法基于连续小波变换，利用辐射能谱的能量频率特性。变换系数生成尺度图图像，通过图像处理提取有效特征值。选取尺度图图像的泽尼克矩表示相应辐射谱的特征向量。最后，利用代表异常分数的马氏距离对给定的辐射谱进行分类。使用从辐射探测器网络收集的实际测量值来评估性能。为了证明所提出的工作的有效性，在异常检测能力方面与基准方法和最新方法进行了比较。实验结果表明，即使在低源本底辐射比下，该方法也能取得较好的效果。

{"title":"Radiation anomaly detection using continuous wavelet transform and Zernike moments","authors":"Assem Abdelhakim","doi":"10.1016/j.apradiso.2026.112432","DOIUrl":"10.1016/j.apradiso.2026.112432","url":null,"abstract":"<div><div>Detecting illicit radioactive materials has been always one of the significant tasks for homeland security due to the radiation emissions of such materials that may endanger the citizens. One of the major challenges in radiation detection is to distinguish between normal or background radiation and anomalous source radiation at low source to background radiation ratios. In this paper, an effective anomaly detection method is proposed to detect anomalous Gamma-ray radiation spectra. The method is based on the continuous wavelet transform to exploit the energy-frequency characteristics of the radiation energy spectrum. A Scalogram image is generated from the transform coefficients, where image processing can be applied for extracting effective feature values. The Zernike moments of the Scalogram image are selected to represent the feature vector of the corresponding radiation spectrum. Finally, classification of the given radiation spectrum is carried out using the Mahalanobis distance that represents the anomaly score. The performance is evaluated using real measurements that are collected from a network of radiation detectors. To present the effectiveness of the proposed work, a comparison is conducted with both benchmark and recent methods in terms of the anomaly detection capabilities. Experimental results show that the proposed method achieves better performance compared to the other methods even at low source to background radiation ratios.</div></div>","PeriodicalId":8096,"journal":{"name":"Applied Radiation and Isotopes","volume":"229 ","pages":"Article 112432"},"PeriodicalIF":1.8,"publicationDate":"2026-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145964956","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Concentration of 40K, 226Ra, 228Ra and 228Th in the main brands of pet food sold in Brazil 巴西主要品牌宠物食品中40K、226Ra、228Ra和228Th的浓度。

IF 1.8 3区工程技术 Q3 CHEMISTRY, INORGANIC & NUCLEAR

Applied Radiation and Isotopes

Pub Date : 2026-01-10 DOI: 10.1016/j.apradiso.2026.112429

Caroline R.A. Carvalho , Leandro B. Silva , Lucas F. Silva , Jonathan O. dos Santos , Carlos O.P. Orejuela , Alexander C.F. Silva , Caroline Mattos Barbosa , Jardel L. Thalhofer , Ademir X. da Silva

Pets are constantly exposed to natural radionuclides through their diet, yet studies on the radiological evaluation of animal food remain scarce, especially in Brazil, one of the leading markets in the pet industry. This research estimated the specific activity concentrations of the natural radionuclides ²²⁶Ra, ²²⁸Ra, ²²⁸Th and ⁴⁰K in representative samples of dog, cat, bird and rabbit food from the most sold brands in Brazil. Measurements were performed by gamma spectrometry using an HPGe detector. The average specific activity concentration of ⁴⁰K in dog, cat, bird and rabbit food resulted in 235

\pm

14, 252

\pm

15, 349

\pm

22 and 567

\pm

31 Bq kg⁻¹ dw, respectively. For ²²⁶Ra, ²²⁸Ra and ²²⁸Th the reported ranges (Bq kg⁻¹ dw) were approximately 0.7–12.4. The effective dose coefficients due to ⁴⁰K ingestion for dogs, cats, birds and rabbits were 8.5 x

1 0^{- 14}

, 9.0 x 10⁻¹³, 4.9 x 10⁻¹² and 1.0 x 10⁻¹² Sv Bq⁻¹, respectively. The external risk index due to gamma radiation for humans handling the food was below the limit of 0.3 mSv year⁻¹ used for restriction in biota, indicating no significant radiological risk to animals or humans. Therefore, the consumption of this commercial food is considered radiologically safe for pets, while the established reference values are important for monitoring and identifying possible radionuclide contamination in food for these animals.

宠物通过饮食不断接触到天然放射性核素，但对动物食品的放射性评估的研究仍然很少，特别是在巴西，宠物行业的主要市场之一。本研究估计了巴西最畅销品牌的狗、猫、鸟和兔食品的代表性样品中天然放射性核素226Ra、228Ra、228Th和40K的比活性浓度。测量是通过伽马能谱使用HPGe探测器进行的。狗粮、猫粮、鸟粮和兔粮中40K的平均比活性浓度分别为235±14、252±15、349±22和567±31 Bq kg-1 dw。对于226Ra， 228Ra和228Th，报告的范围（Bq kg-1 dw）约为0.7-12.4。犬、猫、鸟、兔摄入40K的有效剂量系数分别为8.5 × 10-14、9.0 × 10-13、4.9 × 10-12和1.0 × 10-12 Sv Bq-1。人类处理食品时受到的伽马辐射的外部风险指数低于生物群限制的0.3毫西弗年-1的限值，表明对动物或人类没有显著的辐射风险。因此，食用这种商业食品在放射学上被认为对宠物是安全的，而既定的参考值对于监测和确定这些动物的食物中可能存在的放射性核素污染很重要。

{"title":"Concentration of 40K, 226Ra, 228Ra and 228Th in the main brands of pet food sold in Brazil","authors":"Caroline R.A. Carvalho , Leandro B. Silva , Lucas F. Silva , Jonathan O. dos Santos , Carlos O.P. Orejuela , Alexander C.F. Silva , Caroline Mattos Barbosa , Jardel L. Thalhofer , Ademir X. da Silva","doi":"10.1016/j.apradiso.2026.112429","DOIUrl":"10.1016/j.apradiso.2026.112429","url":null,"abstract":"<div><div>Pets are constantly exposed to natural radionuclides through their diet, yet studies on the radiological evaluation of animal food remain scarce, especially in Brazil, one of the leading markets in the pet industry. This research estimated the specific activity concentrations of the natural radionuclides <sup>226</sup>Ra, <sup>228</sup>Ra, <sup>228</sup>Th and <sup>40</sup>K in representative samples of dog, cat, bird and rabbit food from the most sold brands in Brazil. Measurements were performed by gamma spectrometry using an HPGe detector. The average specific activity concentration of <sup>40</sup>K in dog, cat, bird and rabbit food resulted in 235 <span><math><mrow><mo>±</mo></mrow></math></span> 14, 252 <span><math><mrow><mo>±</mo></mrow></math></span> 15, 349 <span><math><mrow><mo>±</mo></mrow></math></span> 22 and 567 <span><math><mrow><mo>±</mo></mrow></math></span> 31 Bq kg<sup>−1</sup> dw, respectively. For <sup>226</sup>Ra, <sup>228</sup>Ra and <sup>228</sup>Th the reported ranges (Bq kg<sup>−1</sup> dw) were approximately 0.7–12.4. The effective dose coefficients due to <sup>40</sup>K ingestion for dogs, cats, birds and rabbits were 8.5 x <span><math><mrow><mn>1</mn><msup><mn>0</mn><mrow><mo>−</mo><mn>14</mn></mrow></msup></mrow></math></span>, 9.0 x 10<sup>−13</sup>, 4.9 x 10<sup>−12</sup> and 1.0 x 10<sup>−12</sup> Sv Bq<sup>−1</sup>, respectively. The external risk index due to gamma radiation for humans handling the food was below the limit of 0.3 mSv year<sup>−1</sup> used for restriction in biota, indicating no significant radiological risk to animals or humans. Therefore, the consumption of this commercial food is considered radiologically safe for pets, while the established reference values are important for monitoring and identifying possible radionuclide contamination in food for these animals.</div></div>","PeriodicalId":8096,"journal":{"name":"Applied Radiation and Isotopes","volume":"230 ","pages":"Article 112429"},"PeriodicalIF":1.8,"publicationDate":"2026-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146016936","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0