Applied Radiation and Isotopes

Presentation of baseline data on terrestrial gamma radiation (TGR) levels is crucial for assessing the annual effective dose received by the public due to natural radiation exposure. Cumulative doses from various sources can become significant, warranting a spatial understanding of TGR distribution. Few countries have comprehensively mapped TGR on a national scale, often facing challenges due to remote or inaccessible regions. This study investigated the influence of weathered soil groups on TGR dose rates in Sarawak-Borneo, Malaysia, to facilitate insights for TGR projection and isodose mapping...

Three paintings of Thomas Gainsborough (1727-1788), one of the most influential English portrait painters of the late 18th century, from the collection of the Museu de Arte de São Paulo (MASP) - "Francis Rawdon" (1783-1784), "Portrait of Mrs. John Bolton" (1770), and "Drinkstone Park" (1747) - were investigated using portable X-ray fluorescence (pXRF), employing a W tube anode and an XR-100CR detector. These artworks represent the only paintings by Thomas Gainsborough located in the southern hemisphere...

The present study aimed to validate the different radiodiagnostic beam qualities (RQT, WAH and WAV) by the measurements of the X-ray beams HVL of a HOPEWELL generator, X80-225 kV from a high voltage range of 10 at 200 kV, at CNESTEN Gamma and X Calibration Laboratory. The experiments were carried out using the PTW TN 32005 ionization chamber, established at 100 cm from the center of the X-ray tube and connected to a SUPERMAX electrometer. The HVL values were measured by applying the attenuation law to the flow of Kair air kerma, including their uncertainties...

Dose conformity is an essential parameter used in radiotherapy and radiosurgery that measures the correspondence of the dose distribution derived from a Treatment Planning System (TPS) with the actual volume to be treated, the Planning Treatment Volume (PTV). The present work uses a method based on the expansion of dose distributions and PTVs by three-dimensional Zernike polynomials and further comparison of their moments to define a general criterion of dose conformity. To carry on this study, data coming from 20 patients comprising 80 datasets exported from the TPS, which included imaging data (PTVs) and dose distributions corresponding to different treatment modalities: three-dimensional conformal radiotherapy, intensity-modulated radiotherapy (IMRT) and volumetric modulated arc therapy (VMAT), were used...

This work investigates the feasibility of yeast-based impedance measurements for retrospective dosimetry applications. The local environment around yeast cells in a previously developed film-badge was modeled using Geant4. A greater dose response was observed when yeast cells were surrounded by an aluminum-polymer structure, which acted as a conversion layer. Bench-top experiments were conducted using a jar-based dosimeter design that directly combined a finely-ground aluminum conversion medium with yeast powder...

In nuclear radiation detection, some measured radiation counts are lost due to dead time. Estimation of dead time is necessary to restore the counting information in quantitative analysis. This study aims to propose a method for estimating dead time at high counting rate. First of all, a measurement system of pulse interval distribution was used to estimate the true input counting rate of the detection system and implemented in FPGA. Then, a digital pole-zero cancellation technique was introduced in the measurement system to decrease the decay time constant of pulse...

Studies on charge distribution have been carried out in the epi-cadmium neutron induced fission of 238 Pu for the first time. Experimentally fractional cumulative yields (FCY) and independent yields (IY) of various fission products have been measured by using an off-line γ-ray spectrometric technique. From the FCY values, the charge distribution parameters such as the isobaric width parameter (σZ ), most probable charge (ZP ) and the charge polarization (ΔΖEXPT ) as a function of fragment mass were obtained...

The aim of the work presented in this manuscript was to radiolabel methotrexate and prepare radiolabeled methotrexate micelles, an antifolate drug with Tc-99m using QbD approach. The radiolabeling was executed using the experimental design and the radiolabeled drug was further encapsulated in micelles. The authors are of the view that the radiolabeled MTX could be used to target the folate receptor overexpressing cancers such as the kidney, colorectal, breast, brain etc thereby opening newer possibilities to the theranostic applications of the formed conjugate...

In this study, we examined the effectiveness of europium-doped calcium gadolinium silicoborate glasses for determining their physical, mechanical, acoustic and radiation shielding properties with compositions of 25Gd2 O3 -10CaO-10SiO2 -xEu2 O3 -(55-x) B2 O3 (where, x is 0.1, 0.2, 0.3, and 0.4 mol%). These glasses were theoretically analyzed using the Geant4 toolkit and Phy-X PSD software to calculate their performance for x-ray energies ranging from 0.2 to 1.2 MeV. The physical, acoustic and mechanical properties were determined using the Makishima-Mackenzie (MM) model...

Waste liquid stored in the containment sumps of nuclear power plants may contain a variety of radionuclides. Real-time monitoring of containment sump waste liquid can ensure that accidents, such as leakage of cooling water, can be avoided. This paper presents the design of a radioactive monitoring system for waste liquid in a containment sump. The detector and the lead-shield in the measurement unit are optimized through Monte Carlo simulations. Experimental verification showed that the background count rate of the measurement chamber in the system was 418...

The spectrum averaged cross sections (SACS) in standard neutron field, e.g. 252 Cf(s.f.), is a preferable tool for cross section evaluation and validation. A set of reaction measurements with high energy thresholds was previously performed. The presented work focuses on lower energy threshold reactions, namely on the inelastic scattering of the tin foil, more specifically the reaction 117 Sn(n,n')117m Sn, and the zinc foil reaction, namely 67 Zn(n,p)67 Cu. These reactions are of special interest due to their intermediate energy range, which is essential in classical reactor dosimetry and fast reactor dosimetry...

Radiation-based gauges have been widely utilized in the industry as a dependable, non-destructive method of measuring metal layer thickness. It is only possible to trust the conventional radiation thickness meter when the material's composition is known in advance. Thickness measurement errors are to be anticipated in contexts like rolled metal factories, where the real component of the material could diverge greatly from the stated composition. An X-ray-based device was suggested in this study to measure aluminum sheet thickness and identify the type of its alloys...

Early works that used thermoluminescent dosimeters (TLDs) to measure absorbed dose from alpha particles reported relatively high variation (10%) between TLDs, which is undesirable for modern dosimetry applications. This work outlines a method to increase precision for absorbed dose measured using TLDs with alpha-emitting radionuclides by applying an alpha-specific chip factor (CF) that individually characterizes the TLD sensitivity to alpha particles. Variation between TLDs was reduced from 21.8% to 6.7% for the standard TLD chips and 7...

This study explores the structural and optical qualities of LaCa4 O(BO3 )3 (LACOB) phosphors doped with Eu3+ , Dy3+ , and Tb3+ using a microwave-assisted sol-gel technique. It uncovers oxygen-related luminescence defects in LACOB, highlighting emission peaks at 489 and 585 nm for Dy3+ , a distinct sharp peak at 611 nm for Eu3+ in the red spectrum, and a notable green emission for Tb3+ due to specific transitions. The photoluminescence (PL) analysis indicates that luminescence is optimized through precise doping, leveraging dipole interactions, and localized resonant energy transfer, which are influenced by dopant concentration and spatial configuration...

Considerable experimental effort has been aimed at uncovering a reliable way to perform a dosimetric assessment in mixed radiation fields. In fields composed by gammas and neutrons, TLD dosimeters are usually applied to execute such measurements, although there is no consensus on the most favorable strategy to employ them. In this context, TLD-100 measurements within two different core configurations of the IPEN/MB-01 research reactor and Monte Carlo simulations have been used to investigate the behavior of those detectors in multiple mixed radiation fields, deriving a methodology to evaluate the dose deposition in the dosimeter by different gamma and neutron energy spectra and intensities...

In this study, Ibandronate as a third generation of bisphosphonates was labeled with rhenium-188 radionuclide. Production and quality control of 188 Re-IBA radiopharmaceutical was investigated. The radiation absorbed dose of this radiopharmaceutical was evaluated for adult male based on biodistribution data in mice using the RADAR and Sparks and Aydogan methodologies. The 188 Re-IBA was produced with more than 96% radiochemical purity. The highest value of %ID/g was related to bone with 7.11% at 12 h post-injection...

Glass dosimeters are very useful and convenient detection elements in radiation dosimetry. In this study, this glass dosimeter was applied to a BNCT treatment field. Boron Neutron Capture Therapy (BNCT) is a next-generation radiation therapy that can selectively kill only cancer cells. In the BNCT treatment field, both neutrons and secondary gamma-rays are generated. In other words, it is a mixed radiation field of neutrons and gamma-rays. We thus proposed a novel method to measure only gamma-ray dose in the mixed field using two RPLGD (Radiophoto-luminescence Glass Dosimeter) and two sensitivity control filters in order to control the dose response of the filtered RPLGD to be proportional to the air kerma coefficients, even if the gamma-ray energy spectrum is unknown...

Boron neutron capture therapy (BNCT) is an effective binary radiation therapy that depends on nuclear capture reactions. In recent years, BNCT can be performed without a reactor owing to the development of accelerator-based neutron sources. A new BNCT irradiation facility is proposed, which is based on a 15 mA 2.5 MeV proton accelerator with a 100 μm thickness natural lithium target as a neutron converter. A great quantity of studies has shown that neutron beams with different spectra have unique therapeutic effects on tumors...

The Jiangmen Underground Neutrino Observatory (JUNO) is a 20 kt low level radioactivity liquid scintillator detector in a laboratory 650 m underground. An excellent energy resolution and a large volume offer exciting opportunities for addressing many important topics in neutrino physics. High purity nitrogen is an important factor to ensure the low background of the JUNO detector. High Purity Nitrogen (HPN) is used for detector purging, pipe cleaning, and scintillator purification, among other things in JUNO...

The independent isomeric yield ratios (IR) of 128,130,132 Sb, 131,133 Te, 132,134,136 I, 135 Xe and 138 Cs have been measured in the epi-cadmium neutron induced fission of 233 U by using an off-line gamma-ray spectrometric technique. The average neutron energy of the epi-cadmium reactor neutron spectrum is 1.9 MeV. The root mean square fragment angular momenta (JRMS ) were deduced from the IR values by using spin dependent statistical model analysis. The IR and JRMS values of considered fission products in the epi-cadmium neutron induced fission of 233 U were compared with the literature data in the thermal neutron induced fission of 233 U to examine the influence of excitation energy on nuclear structure effect...