Pub Date : 2026-02-06DOI: 10.1016/j.radphyschem.2026.113699
Samar , N. Amjed , A. Naz , A.M. Wajid
An evaluation of production cross sections for the medically and industrially important cobalt radionuclides, namely, 58mCo, 57Co, and 56Co, was performed. Experimental data from literature were compiled and critically analyzed in comparison with theoretical results of three nuclear model codes TALYS-1.9, EMPIRE-3.2, and ALICE-IPPE. A theory-aided evaluation methodology was used to generate the recommended Cross sections for each production route and their corresponding impurities. Using these recommended datasets, thick target yields were calculated for all investigated production routes with their impurities. The best production routes were suggested with optimum energy ranges for high-purity production of 58mCo, 57Co, and 56Co radionuclides. In particular, the 55Mn(α,n)58mCo (13 → 7 MeV), 57Fe(p,n)57Co (15 → 6 MeV), and 56Fe(p,n)56Co (16 → 8 MeV) reactions were found to be the most favorable for reliable cyclotron production.
{"title":"Optimization of the cross section data for the cyclotron production of 56Co, 57Co, and 58mCo radionuclides","authors":"Samar , N. Amjed , A. Naz , A.M. Wajid","doi":"10.1016/j.radphyschem.2026.113699","DOIUrl":"10.1016/j.radphyschem.2026.113699","url":null,"abstract":"<div><div>An evaluation of production cross sections for the medically and industrially important cobalt radionuclides, namely, <sup>58m</sup>Co, <sup>57</sup>Co, and <sup>56</sup>Co, was performed. Experimental data from literature were compiled and critically analyzed in comparison with theoretical results of three nuclear model codes TALYS-1.9, EMPIRE-3.2, and ALICE-IPPE. A theory-aided evaluation methodology was used to generate the recommended Cross sections for each production route and their corresponding impurities. Using these recommended datasets, thick target yields were calculated for all investigated production routes with their impurities. The best production routes were suggested with optimum energy ranges for high-purity production of <sup>58m</sup>Co, <sup>57</sup>Co, and <sup>56</sup>Co radionuclides. In particular, the <sup>55</sup>Mn(α,n)<sup>58m</sup>Co (13 → 7 MeV), <sup>57</sup>Fe(p,n)<sup>57</sup>Co (15 → 6 MeV), and <sup>56</sup>Fe(p,n)<sup>56</sup>Co (16 → 8 MeV) reactions were found to be the most favorable for reliable cyclotron production.</div></div>","PeriodicalId":20861,"journal":{"name":"Radiation Physics and Chemistry","volume":"243 ","pages":"Article 113699"},"PeriodicalIF":2.8,"publicationDate":"2026-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146134648","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-06DOI: 10.1016/j.radphyschem.2026.113693
A. Khallouqi , H. Sekkat , O. Elmouden , N. Ghosne , I. Lagrini , A. Halimi , O. El rhazouani
Accurate dosimetry is crucial for optimizing radiotherapy outcomes, balancing tumor control with healthy tissue sparing. Water phantoms represent the gold standard due to their tissue-equivalent properties, yet practical limitations such as setup complexity and portability drive the need for solid alternatives. This study employs Monte Carlo simulations using the GATE platform to comprehensively evaluate the dosimetric equivalence of common solid phantoms; RW3, Nylon, PMMA, Polyester, Polyethylene, Polystyrene, Original Plastic Water, and Virtual Water; against water for a 6 MV flattened photon beam from a Varian TrueBeam linear accelerator. Dosimetric parameters, including percentage depth dose (PDD) curves, lateral dose profiles at depth of 10 cm, and 3D volumetric dose distributions, were assessed under identical beam configurations (10 × 10 cm2 field size, 100 cm SSD). Validation against experimental data acquired using a PTW Semiflex ionization chamber (0.125 cm3) in a motorized water phantom confirmed simulation fidelity, with gamma pass rates exceeding 99% (2%/2 mm criterion). Results ranked RW3 as the superior water substitute (mean PDD deviation: 0.65%; lateral: 4.68%; RMSE: 5.62%), followed by Plastic and Virtual phantoms, while Nylon, and Polyester exhibited unacceptable deviations (>10%). Polyethylene showed anomalous positive bias (+3.98% PDD). These findings, benchmarked against IAEA and AAPM tolerance criteria (±2% for reference dosimetry, ±3% for routine QA), highlight material-specific radiological properties influencing photon interactions, underscoring RW3's utility for clinical quality assurance while identifying materials requiring correction factors (Polystyrene, Polyethylene) or unsuitable for clinical use without extensive adjustments (Nylon, Polyester exceeding 10% deviation).
{"title":"Monte Carlo-based assessment of solid phantom equivalence to water in radiation therapy quality assurance","authors":"A. Khallouqi , H. Sekkat , O. Elmouden , N. Ghosne , I. Lagrini , A. Halimi , O. El rhazouani","doi":"10.1016/j.radphyschem.2026.113693","DOIUrl":"10.1016/j.radphyschem.2026.113693","url":null,"abstract":"<div><div>Accurate dosimetry is crucial for optimizing radiotherapy outcomes, balancing tumor control with healthy tissue sparing. Water phantoms represent the gold standard due to their tissue-equivalent properties, yet practical limitations such as setup complexity and portability drive the need for solid alternatives. This study employs Monte Carlo simulations using the GATE platform to comprehensively evaluate the dosimetric equivalence of common solid phantoms; RW3, Nylon, PMMA, Polyester, Polyethylene, Polystyrene, Original Plastic Water, and Virtual Water; against water for a 6 MV flattened photon beam from a Varian TrueBeam linear accelerator. Dosimetric parameters, including percentage depth dose (PDD) curves, lateral dose profiles at depth of 10 cm, and 3D volumetric dose distributions, were assessed under identical beam configurations (10 × 10 cm<sup>2</sup> field size, 100 cm SSD). Validation against experimental data acquired using a PTW Semiflex ionization chamber (0.125 cm<sup>3</sup>) in a motorized water phantom confirmed simulation fidelity, with gamma pass rates exceeding 99% (2%/2 mm criterion). Results ranked RW3 as the superior water substitute (mean PDD deviation: 0.65%; lateral: 4.68%; RMSE: 5.62%), followed by Plastic and Virtual phantoms, while Nylon, and Polyester exhibited unacceptable deviations (>10%). Polyethylene showed anomalous positive bias (+3.98% PDD). These findings, benchmarked against IAEA and AAPM tolerance criteria (±2% for reference dosimetry, ±3% for routine QA), highlight material-specific radiological properties influencing photon interactions, underscoring RW3's utility for clinical quality assurance while identifying materials requiring correction factors (Polystyrene, Polyethylene) or unsuitable for clinical use without extensive adjustments (Nylon, Polyester exceeding 10% deviation).</div></div>","PeriodicalId":20861,"journal":{"name":"Radiation Physics and Chemistry","volume":"243 ","pages":"Article 113693"},"PeriodicalIF":2.8,"publicationDate":"2026-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146134652","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-06DOI: 10.1016/j.radphyschem.2026.113697
K. Venkataramaniah, C. Scheidenberger, K. Vijay Sai, Deepa Seetharaman
{"title":"On the Precision and Accuracy of Audi-Wapstra-Wang Extrapolations for Nuclear Mass Predictions","authors":"K. Venkataramaniah, C. Scheidenberger, K. Vijay Sai, Deepa Seetharaman","doi":"10.1016/j.radphyschem.2026.113697","DOIUrl":"https://doi.org/10.1016/j.radphyschem.2026.113697","url":null,"abstract":"","PeriodicalId":20861,"journal":{"name":"Radiation Physics and Chemistry","volume":"77 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146134653","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-05DOI: 10.1016/j.radphyschem.2026.113691
Sarah Sanaei Nasab , Neda Mollakhalili-Meybodi , Masoumeh Arab , Seyede Marzieh Hosseini , Hossein Fallahzadeh
Quinoa seeds were irradiated at doses of 0.5, 1, 2.5, 5, 7.5, and 10 kGy and then their technological characteristics were analyzed as physicochemical, functional, rheological, thermal, pasting, textural, FTIR, and morphological parameters.
Results indicated that gamma irradiation affected the glycosidic linkage of starch, the amylose/amylopectin ratio, and the tertiary structure of proteins, depending on dose. WHC (1.88 ± 0.01%), OHC (1.76 ± 0.01%), and WSI (4.09 ± 0.02 g/g) increased at 10 kGy, compared with the control, verified the enhanced hydrolytic depolymerization of starch. Significant decrease in the viscosity parameters (peak, hold, final, and setback), G’ and G”, and significant increase in tan δ (1.37 × 10−1±0.02 to 2.43 × 10−1±0.05) was observed. The lowest gelatination temperatures (onset, peak, conclusion) and enthalpy change of gelatinization were observed in sample irradiated at 10 kGy, which was attributed to the highest damage in starch structure induced by gamma irradiation. A decrease in hardness with increasing doses of gamma irradiation indicated increased crystallization of amylopectin. The analysis of FTIR confirmed the effects of gamma irradiation on carbohydrate and water absorption capacity, showing a reduction in O–H stretching vibrations and increases in C–H stretching and CO stretch, especially at 10 kGy. Scanning electron microscopy showed surface cracks and weakening of starch granules at 7.5 and 10 kGy. These results confirmed that higher doses affected technological properties and may be useful in food formulation.
{"title":"Effect of gamma irradiation treatment on the technological characteristics of quinoa flour","authors":"Sarah Sanaei Nasab , Neda Mollakhalili-Meybodi , Masoumeh Arab , Seyede Marzieh Hosseini , Hossein Fallahzadeh","doi":"10.1016/j.radphyschem.2026.113691","DOIUrl":"10.1016/j.radphyschem.2026.113691","url":null,"abstract":"<div><div>Quinoa seeds were irradiated at doses of 0.5, 1, 2.5, 5, 7.5, and 10 kGy and then their technological characteristics were analyzed as physicochemical, functional, rheological, thermal, pasting, textural, FTIR, and morphological parameters.</div><div>Results indicated that gamma irradiation affected the glycosidic linkage of starch, the amylose/amylopectin ratio, and the tertiary structure of proteins, depending on dose. WHC (1.88 ± 0.01%), OHC (1.76 ± 0.01%), and WSI (4.09 ± 0.02 g/g) increased at 10 kGy, compared with the control, verified the enhanced hydrolytic depolymerization of starch. Significant decrease in the viscosity parameters (peak, hold, final, and setback), G’ and G”, and significant increase in tan δ (1.37 × 10<sup>−1</sup>±0.02 to 2.43 × 10<sup>−1</sup>±0.05) was observed. The lowest gelatination temperatures (onset, peak, conclusion) and enthalpy change of gelatinization were observed in sample irradiated at 10 kGy, which was attributed to the highest damage in starch structure induced by gamma irradiation. A decrease in hardness with increasing doses of gamma irradiation indicated increased crystallization of amylopectin. The analysis of FTIR confirmed the effects of gamma irradiation on carbohydrate and water absorption capacity, showing a reduction in O–H stretching vibrations and increases in C–H stretching and C<img>O stretch, especially at 10 kGy. Scanning electron microscopy showed surface cracks and weakening of starch granules at 7.5 and 10 kGy. These results confirmed that higher doses affected technological properties and may be useful in food formulation.</div></div>","PeriodicalId":20861,"journal":{"name":"Radiation Physics and Chemistry","volume":"243 ","pages":"Article 113691"},"PeriodicalIF":2.8,"publicationDate":"2026-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146134651","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-05DOI: 10.1016/j.radphyschem.2026.113660
A.V. Ponomarev, M.M. Belova
The influence of nitric acid and hydrocarbon diluent (from n-hexane to n-pentadecane; as well as isooctane) on the radiolytic formation of phosphorus-containing products in a 30 wt% solution of tri-n-butyl phosphate (TBP) was investigated. The efficient formation of nitro and hydroxy derivatives of TBP with a simultaneous decrease in the yield of alkyl phosphonates and alkyl phosphates is the main difference between the radiolysis of acidified and acid-free solutions. In general, the composition of radiolysis products depends on the diluent. At a dose of up to 30 kGy, the presence of nitric acid in the solution increases the yield of TBP degradation from an average of 74 to 90 nmol J−1, but this yield is practically independent of the number of C atoms in the diluent molecule.
{"title":"The combined effect of nitric acid and hydrocarbon diluent on the radiolytic transformations of tributyl phosphate","authors":"A.V. Ponomarev, M.M. Belova","doi":"10.1016/j.radphyschem.2026.113660","DOIUrl":"10.1016/j.radphyschem.2026.113660","url":null,"abstract":"<div><div>The influence of nitric acid and hydrocarbon diluent (from n-hexane to n-pentadecane; as well as isooctane) on the radiolytic formation of phosphorus-containing products in a 30 wt% solution of tri-<em>n</em>-butyl phosphate (TBP) was investigated. The efficient formation of nitro and hydroxy derivatives of TBP with a simultaneous decrease in the yield of alkyl phosphonates and alkyl phosphates is the main difference between the radiolysis of acidified and acid-free solutions. In general, the composition of radiolysis products depends on the diluent. At a dose of up to 30 kGy, the presence of nitric acid in the solution increases the yield of TBP degradation from an average of 74 to 90 nmol J<sup>−1</sup>, but this yield is practically independent of the number of C atoms in the diluent molecule.</div></div>","PeriodicalId":20861,"journal":{"name":"Radiation Physics and Chemistry","volume":"243 ","pages":"Article 113660"},"PeriodicalIF":2.8,"publicationDate":"2026-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146134655","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-04DOI: 10.1016/j.radphyschem.2026.113662
Ruzan Sukiasyan , Mane Sahakyan , Nelli Gharibyan , Armen Ayvazyan , Kyrill Suponitsky , Astghik Danghyan , Armen Atanesyan
In this work, L-arginine sulfates (LAS and LAS∙2H2O) were studied both experimentally and theoretically. The crystal and molecular structure of LAS and LAS∙2H2O were determined by single-crystal X-ray diffraction method at 120 K and 295 K. It was shown that the crystals LAS (L-Arg2+)∙(SO42−) and LAS∙2H2O ((L-Arg2+)∙(SO42−)∙2H2O) crystallize in the orthorhombic (space group P21212) and monoclinic (space group P21) systems, respectively. First-principles calculations of dielectric and optical properties, as well as the structural computational optimization procedure, were performed. The UV-Vis transmittance spectrum was recorded, and the second harmonic generation efficiency was investigated. Theoretical results for the optical properties were compared with experimental data․
{"title":"Theoretical and experimental study of L-arginine sulfates","authors":"Ruzan Sukiasyan , Mane Sahakyan , Nelli Gharibyan , Armen Ayvazyan , Kyrill Suponitsky , Astghik Danghyan , Armen Atanesyan","doi":"10.1016/j.radphyschem.2026.113662","DOIUrl":"10.1016/j.radphyschem.2026.113662","url":null,"abstract":"<div><div>In this work, L-arginine sulfates (LAS and LAS∙2H<sub>2</sub>O) were studied both experimentally and theoretically. The crystal and molecular structure of LAS and LAS∙2H<sub>2</sub>O were determined by single-crystal X-ray diffraction method at 120 K and 295 K. It was shown that the crystals LAS (L-Arg<sup>2+</sup>)∙(SO<sub>4</sub><sup>2−</sup>) and LAS∙2H<sub>2</sub>O ((L-Arg<sup>2+</sup>)∙(SO<sub>4</sub><sup>2−</sup>)∙2H<sub>2</sub>O) crystallize in the orthorhombic (space group <em>P</em>2<sub>1</sub>2<sub>1</sub>2) and monoclinic (space group <em>P</em>2<sub>1</sub>) systems, respectively. First-principles calculations of dielectric and optical properties, as well as the structural computational optimization procedure, were performed. The UV-Vis transmittance spectrum was recorded, and the second harmonic generation efficiency was investigated. Theoretical results for the optical properties were compared with experimental data․</div></div>","PeriodicalId":20861,"journal":{"name":"Radiation Physics and Chemistry","volume":"243 ","pages":"Article 113662"},"PeriodicalIF":2.8,"publicationDate":"2026-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146134659","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-03DOI: 10.1016/j.radphyschem.2026.113689
Anand Kumar Sethukali , Dongbin Park , Cheorun Jo , Hyun Jung Lee
In this study, semi-moist pet food samples were irradiated with electron beam and X-rays at 0, 2.5, 5, and 10 kGy. Samples were stored under refrigeration, and volatile compounds were analyzed on days 0 and 60. X-ray irradiation produced more volatile compounds than electron beam, likely due to differences in free radical formation and radiation-matter interaction characteristics. A dose of 10 kGy promoted oxidative reactions, increasing aldehydes, ketones, and carboxylic compounds, while 5 kGy resulted in more alkanes, indicating hydrocarbon breakdown and distinct flavor development. Notably, 1,3-di-tert-butylbenzene increased consistently at 10 kGy compared to controls, suggesting formation through packaging antioxidant degradation and migration into the fat matrix, supporting its potential role as an irradiation- and packaging-related marker in semi-moist pet foods. Storage conditions significantly influenced volatile compound changes, emphasizing the need for further investigation. These results highlight the importance of optimizing irradiation dose and storage conditions to ensure the safety and quality of semi-moist pet foods, with volatile compound profiles used as chemical indicators of potential sensory changes relevant to product quality.
{"title":"Understanding key volatiles in semi-moist pet foods treated with electron beam and X-ray irradiation","authors":"Anand Kumar Sethukali , Dongbin Park , Cheorun Jo , Hyun Jung Lee","doi":"10.1016/j.radphyschem.2026.113689","DOIUrl":"10.1016/j.radphyschem.2026.113689","url":null,"abstract":"<div><div>In this study, semi-moist pet food samples were irradiated with electron beam and X-rays at 0, 2.5, 5, and 10 kGy. Samples were stored under refrigeration, and volatile compounds were analyzed on days 0 and 60. X-ray irradiation produced more volatile compounds than electron beam, likely due to differences in free radical formation and radiation-matter interaction characteristics. A dose of 10 kGy promoted oxidative reactions, increasing aldehydes, ketones, and carboxylic compounds, while 5 kGy resulted in more alkanes, indicating hydrocarbon breakdown and distinct flavor development. Notably, 1,3-di-<em>tert</em>-butylbenzene increased consistently at 10 kGy compared to controls, suggesting formation through packaging antioxidant degradation and migration into the fat matrix, supporting its potential role as an irradiation- and packaging-related marker in semi-moist pet foods. Storage conditions significantly influenced volatile compound changes, emphasizing the need for further investigation. These results highlight the importance of optimizing irradiation dose and storage conditions to ensure the safety and quality of semi-moist pet foods, with volatile compound profiles used as chemical indicators of potential sensory changes relevant to product quality.</div></div>","PeriodicalId":20861,"journal":{"name":"Radiation Physics and Chemistry","volume":"243 ","pages":"Article 113689"},"PeriodicalIF":2.8,"publicationDate":"2026-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146110479","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-03DOI: 10.1016/j.radphyschem.2026.113646
Mehmet Bektasoglu , Abdullah S. Bayraktar
We introduce GRASP-X, a fast and user-friendly online tool for computing key gamma-ray shielding parameters, including the mass attenuation coefficient (MAC), half-value layer (HVL), tenth-value layer (TVL), mean free path (MFP), and effective atomic number (). GRASP-X is based on the previously developed offline version ”GRASP” and is freely accessible at https://nuclearandparticle.sakarya.edu.tr/grasp-x. The tool computes these parameters at both standard gamma-ray energies and absorption edges, producing graphical outputs and downloadable tables in approximately one second. To evaluate its performance, a wide range of previously studied materials — including glasses and composites — was analyzed. MACs, HVLs, and values obtained with GRASP-X were benchmarked against results from established computational tools, experimental measurements, and theoretical predictions. GRASP-X shows excellent agreement with XCOM across nearly the entire gamma-ray energy range, including absorption edges, and its MAC results are consistent with those calculated using simulation codes such as PHITS and MCNP6. Although direct comparison with Phy-X at absorption edges was limited by the absence of corresponding data, GRASP-X results agree well with Phy-X at standard energies. The effective atomic numbers computed by GRASP-X also exhibit strong consistency with those from Auto-, particularly within the Compton interaction regime.
{"title":"GRASP-X: A user-friendly web-based code to compute various gamma shielding parameters","authors":"Mehmet Bektasoglu , Abdullah S. Bayraktar","doi":"10.1016/j.radphyschem.2026.113646","DOIUrl":"10.1016/j.radphyschem.2026.113646","url":null,"abstract":"<div><div>We introduce GRASP-X, a fast and user-friendly online tool for computing key gamma-ray shielding parameters, including the mass attenuation coefficient (MAC), half-value layer (HVL), tenth-value layer (TVL), mean free path (MFP), and effective atomic number (<span><math><msub><mrow><mi>Z</mi></mrow><mrow><mi>eff</mi></mrow></msub></math></span>). GRASP-X is based on the previously developed offline version ”GRASP” and is freely accessible at <span><span>https://nuclearandparticle.sakarya.edu.tr/grasp-x</span><svg><path></path></svg></span>. The tool computes these parameters at both standard gamma-ray energies and absorption edges, producing graphical outputs and downloadable tables in approximately one second. To evaluate its performance, a wide range of previously studied materials — including glasses and composites — was analyzed. MACs, HVLs, and <span><math><msub><mrow><mi>Z</mi></mrow><mrow><mi>eff</mi></mrow></msub></math></span> values obtained with GRASP-X were benchmarked against results from established computational tools, experimental measurements, and theoretical predictions. GRASP-X shows excellent agreement with XCOM across nearly the entire gamma-ray energy range, including absorption edges, and its MAC results are consistent with those calculated using simulation codes such as PHITS and MCNP6. Although direct comparison with Phy-X at absorption edges was limited by the absence of corresponding data, GRASP-X results agree well with Phy-X at standard energies. The effective atomic numbers computed by GRASP-X also exhibit strong consistency with those from Auto-<span><math><msub><mrow><mi>Z</mi></mrow><mrow><mi>e</mi><mi>f</mi><mi>f</mi></mrow></msub></math></span>, particularly within the Compton interaction regime.</div></div>","PeriodicalId":20861,"journal":{"name":"Radiation Physics and Chemistry","volume":"243 ","pages":"Article 113646"},"PeriodicalIF":2.8,"publicationDate":"2026-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146110481","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-02DOI: 10.1016/j.radphyschem.2026.113682
Eda Kaya Pepele , Songül Barlaz Us
Objective
To quantitatively evaluate the modulation of the maximum (D_max), mean (D_mean), and minimum (D_min) dose response at different tissue densities by field width (FW) and pitch factor in helical tomotherapy in a multi density phantom and to characterize the mass density dose relationship using single breakpoint piecewise linear models.
Materials and methods
Helical tomotherapy plans were generated on a cylindrical “cheese” phantom containing inserts with eight different mass densities representing lung, soft-tissue, and bone like regions for three FW values (1.0, 2.5, and 5.0 cm) and four pitch values. The modulation factor was maintained. For each combination, the D_max, D_mean, and D_min values for the inserts were recorded and analyzed using simple linear and single breakpoint piecewise linear models, with mass density as the independent variable and the dose metrics as the dependent variables. Model fit was assessed using the Akaike information criterion (AIC) and coefficient of determination (R2), and factor effects were evaluated using a multifactor ANOVA.
Results
Across all FW–pitch combinations, the mass density–dose relationship exhibited a clearly non-linear inverted V profile. Piecewise models, particularly for D_max and D_mean, outperformed linear models, with lower AIC and higher R2 values. The breakpoints were mostly clustered around the water-equivalent regions. In the ANOVA, the mass density, dose metrics, and FW showed significant main effects, whereas the main effect of pitch was not significant within the investigated range of values.
Conclusion
The findings obtained in the multi-density phantom indicate that the dominant determinant of density dependent dose response in helical tomotherapy is tissue mass density, whereas FW and pitch behave as geometric parameters that secondarily modulate the dose response while preserving an inverted V baseline profile.
{"title":"Density-dependent dose response to field width and pitch variations in helical tomotherapy: a multi-density phantom and piecewise regression analysis","authors":"Eda Kaya Pepele , Songül Barlaz Us","doi":"10.1016/j.radphyschem.2026.113682","DOIUrl":"10.1016/j.radphyschem.2026.113682","url":null,"abstract":"<div><h3>Objective</h3><div>To quantitatively evaluate the modulation of the maximum (D_max), mean (D_mean), and minimum (D_min) dose response at different tissue densities by field width (FW) and pitch factor in helical tomotherapy in a multi density phantom and to characterize the mass density dose relationship using single breakpoint piecewise linear models.</div></div><div><h3>Materials and methods</h3><div>Helical tomotherapy plans were generated on a cylindrical “cheese” phantom containing inserts with eight different mass densities representing lung, soft-tissue, and bone like regions for three FW values (1.0, 2.5, and 5.0 cm) and four pitch values. The modulation factor was maintained. For each combination, the D_max, D_mean, and D_min values for the inserts were recorded and analyzed using simple linear and single breakpoint piecewise linear models, with mass density as the independent variable and the dose metrics as the dependent variables. Model fit was assessed using the Akaike information criterion (AIC) and coefficient of determination (R<sup>2</sup>), and factor effects were evaluated using a multifactor ANOVA.</div></div><div><h3>Results</h3><div>Across all FW–pitch combinations, the mass density–dose relationship exhibited a clearly non-linear inverted V profile. Piecewise models, particularly for D_max and D_mean, outperformed linear models, with lower AIC and higher R<sup>2</sup> values. The breakpoints were mostly clustered around the water-equivalent regions. In the ANOVA, the mass density, dose metrics, and FW showed significant main effects, whereas the main effect of pitch was not significant within the investigated range of values.</div></div><div><h3>Conclusion</h3><div>The findings obtained in the multi-density phantom indicate that the dominant determinant of density dependent dose response in helical tomotherapy is tissue mass density, whereas FW and pitch behave as geometric parameters that secondarily modulate the dose response while preserving an inverted V baseline profile.</div></div>","PeriodicalId":20861,"journal":{"name":"Radiation Physics and Chemistry","volume":"243 ","pages":"Article 113682"},"PeriodicalIF":2.8,"publicationDate":"2026-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146110484","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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