Neutron Activation Research Articles (Page 1)

Abstract Neutral pressure gauges of the ASDEX type (APG) are an important diagnostic tool for monitoring particle exhaust in fusion reactors with magnetic confinement.
To improve their performance under the challenging conditions of long-pulse operation, neutron irradiation, and high neutral pressures, alternative cathode materials have been investigated.

This study focuses on the use of carbide cathodes—specifically hafnium carbide (HfC) and zirconium carbide (ZrC)—as thermionic emitters in APGs. We evaluated a Wendelstein 7-X-like and an ITER-like design. Stable operation is achieved with both designs, whereas the ITER-like design permits higher thermionic currents. Laboratory experiments have shown that carbides exhibit a much stronger interaction with hydrogen and helium compared to materials such as tungsten or lanthanum hexaboride, leading to a significant increase in the work function and a corresponding reduction in thermionic emission at high pressures. 

A pressure gauge with an indirectly heated ZrC cathode was also tested during plasma operation in the Large Helical Device (LHD), where a gradual increase in heating current was observed. This effect was caused by shrinkage of the cathode’s carbon blocks, which limits the lifetime of the cathode unit to about 300 hours in this special case.

The results demonstrate both the potential and the limitations of carbide cathodes for long-term use in fusion-relevant environments.

This review focuses on the development of Indole based colorimetric and fluorescent chemosensors for the detection of bivalent and trivalent cations including Cu (II), Hg (II), Zn (II), Co (II), Cd (II), Pb (II), Ni (II), Fe (II), Mg(II) and Fe (III), Al (III) ions as well as other metal cations detection. Various sophisticated methods like inductively coupled plasma mass spectroscopy, X-ray spectroscopy, fluorescence spectrometry, voltammetry, atomic absorption spectrometry (AAS), atomic fluorescence spectrometry, high-performance liquid chromatography (HPLC), flow injection analysis (FIA), electrothermal atomization atomic absorption spectrometry (ETAAS), neutron activation analysis, electrophoresis and ion-pair chromatography have been employed to recognize bivalent and trivalent cations in different matrixes like environmental, agricultural and biological. Despite having high sensitivity and selectivity, these methods have some drawbacks like time-consuming, high cost of equipment, required highly skilled technicians and tedious sample preparation. Colorimetric and fluorescent sensors are gaining popularity due to some inherent properties like cost-effectiveness, rapid response and various optical responses even at a trace level of analytes. Different photophysical mechanisms like photo-induced electron transfer (PET), intramolecular charge transfer (ICT) and chelation enhanced fluorescence (CHEF) play an important role in the detection of these metal cations. Indole derivatives exhibited a broad spectrum of biological activity, such as antioxidant, anti-HIV, antibacterial, antimalarial, antiviral, antitubercular, anti-inflammatory, anticancer, antidiabetic and anticholinesterase properties. In this review, we have focused on the applications of Indole based colorimetric and fluorescence chemosensors. Indole and its derivatives were found well-suited for the detection of bivalent and trivalent cations because these compounds exhibited significant photophysical properties due to the presence of ten π electrons, which move throughout the ring and also the ability to form metal complexes with these metal cations due to presence of N- donor atom in Indole ring. The work done on the applications of Indole fluorescent during the period 2011 to 2025 is presented in tabular for better understanding. This review also highlighted various methods of synthesis of Indole and its derivatives. Further, the sensing performances have been compared with some reported organic sensors as presented in tabular form.

Radiopharmaceuticals offer targeted treatment by combining diagnostic or therapeutic radionuclides with biologically active molecules. Auranofin is the only Food and Drug Administration (FDA) approved gold(I) complex, originally developed for the treatment of rheumatoid arthritis. Recent evidence has highlighted its potential as an anticancer agent due to its ability to disrupt redox signaling, inhibit thioredoxin reductase, and impair glycolytic metabolism. This study aims to incorporate the true theranostic radionuclide 198Au into the Auranofin scaffold and evaluate its impact in-vitro on cancer cells. Carrier-added (c.a.)198Au was produced via neutron activation of 197Au and subsequently converted into c.a. H [198Au] [AuCl₄]. Downscaled synthetic protocols were developed to sequentially generate c.a. [198Au] [Au(tht)Cl], [198Au] [Au(PEt₃)Cl], and [198Au]Auranofin. Radiochemical purity was evaluated using radio-high performance liquid chromatography, and in vitro stability was assessed in human serum albumin (HSA) over 72h. Cytotoxic and metabolic activity were investigated in MCF7 and PC3 cancer cell lines using the cell viability assay 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT assay) and hexokinase assay, respectively. [198Au]Auranofin (c.a.) was obtained with a yield of 57.0 ± 3.2% and a radiochemical purity of 96.2 ± 3.9%. The compound demonstrated stability in human serum albumin, maintaining 96.9 ± 2.5% integrity over 72h. In vitro studies revealed that c.a. [198Au]Auranofin exhibited enhanced cytotoxicity and significant hexokinase inhibition compared to its non-radioactive counterpart, while the precursor complexes remained non-toxic up to 20µM. Viability loss was both concentration and radioactivity dependent across both cell lines. [198Au]Auranofin (c.a.) represents a stable and effective radiogold-based radiopharmaceutical agent, offering redox-targeted cytotoxicity alongside β⁻ emission mediated cell death and γ emission based imaging potential. These findings highlight c.a. [198Au]Auranofin as a promising radiogold-based theranostic candidate, offering dual capabilities in targeted cytotoxicity and nuclear imaging. While the in vitro results are encouraging, further in vivo and translational studies are warranted to fully evaluate its clinical potential in nuclear medicine guided cancer therapy.

Objectives: This paper reports the preclinical evaluation of stable tumor-specific gold nanoparticles (AuNPs) activated by neutron irradiation as a therapeutic option for the treatment of cancers characterized by high tumor angiogenesis. Methods: A selection of promising AuNPs with high avidity to αvβ3-expressing glioma (U-87 MG) cells (IC50 = 82–104 nM) were chosen with different surface loading of Arg-Gly-Asp (RGD) peptides as tumor targeting vectors for integrin αvβ3, a target which is overexpressed in tissues displaying high tumor angiogenesis. Three different [198Au]AuNPs were evaluated applying three injection methods, intravenous (i.v.), intraperitoneal (i.p.), and intratumoral (i.t.), each in a group of six U-87 MG xenograft–bearing mice (54 female athymic nude mice in total). Their biodistribution and tumor accumulation was assessed by in vivo imaging within 1–7 days after injection and 7 days after injection by ex vivo measurement. Results: The developed [198Au]AuNPs exhibited suboptimal biodistribution by i.v. application (accumulation pattern tail > liver > spleen, no significant tumor accumulation) and by i.p. application (accumulation pattern spleen >> liver > pancreas, slight tumor accumulation of <0.3 %ID/g). However, an acceptable biodistribution by i.t. application was observed (5.5 %ID/g in liver, 4.9 %ID/g in spleen, and 3.0 %ID/g in tumor). Conclusions: Despite the very promising in vitro results, the in vivo evaluation suggests that the [198Au]AuNPs represent a platform for the development of restricted therapeutic strategies.

Neutron activation in interrupted neutron beams.

Performance of the borate glasses doped with some rare earth compounds during the neutron irradiation: Analysis for the mass removal cross section of fast neutrons and secondary gamma-ray emission

This study aims to investigate the atomic-scale mechanisms of irradiation damage in hexagonal boron nitride (h-BN) and the effects of neutron irradiation on its microstructure under various conditions. Molecular dynamics simulations are employed to analyze the impact of the neutron incident energy, direction, and flux on the h-BN structure. These results indicate that the aforementioned factors influence both the type and distribution of defects in h-BN. Lower energy neutrons can generate N-vacancies due to the lower displacement threshold energy of the N atoms. The maximum kinetic energy in the collision cascades and lattice-atom displacement are crucial for defect formation. Moreover, increasing flux gradually leads to the formation of an amorphous surface layer, while the deeper regions maintain crystalline order. This observation is consistent with recent experimental results, suggesting that thermal neutron irradiation promotes a transition from sp2 to sp3 hybridization and leads to surface amorphization. These insights provide guidance for the development of radiation resistant neutron detection devices.

Optical spectroscopy study of damage induced in nitrogen-doped 6H-SiC by neutron irradiation

Evaluation of Boron Neutron Capture Therapy for treating canine oral malignant melanoma.

Qualification of L-DED 316L for nuclear reactor core applications – Material characteristics before and after neutron irradiation

Determination of neutron and gamma ray shielding properties, secondary radiation formations and neutron damage of composites containing polyester/pyrite/titanium diboride.

Design and assembly of in situ electrical characterization setup for semiconductor devices in mixed neutron and gamma radiation at the University of Florida Training Reactor: Application to HZO-based MFM capacitors

Mechanical properties, strain hardening, and fracture behavior of Ultrasonic Additively Manufactured Zircaloy-4 after Low-Temperature Neutron Irradiation

Novel insights into GaN-HEMT behaviour under multi-particle irradiation.

Abstract We developed the Mg 2+ - and Pr 3+ -co-doped LiTaO 3 ceramics using 6 Li or n Li ( n Li represents isotope content in the natural abundance ratio) as thermoluminescence (TL) materials for thermal neutron detection. Here, Mg acts as an electron trap and Pr as a luminescent center. Photoluminescence spectra indicate that sharp emission peaks at 550–650 nm originating from 4f–4f transitions of Pr 3+ . Since thermal neutron irradiation facilities generally accompany gamma rays, we first confirmed similar TL intensities in both samples after X-ray irradiation, which indicates that they have similar TL response to gamma rays. After thermal neutron irradiation, the 6 Li-enriched sample exhibited a much higher TL intensity than that of the n Li-containing one, because the 6 Li-enriched sample contains a higher fraction of 6 Li, which has a large neutron capture cross-section, than the n Li-containing sample. The difference in TL intensities within ±15 K of the peak temperature showed excellent linearity at 10 6 –10 10 neutrons cm −2 .

Evaluation of Unstable Radioisotope production after fast neutron irradiation by neutron shielding concretes by Monte Carlo simulations.

Design and modeling of Cf-252 -based neutron irradiator for NAA: MCNP6 simulations of dose rate and neutron fluxes.

Study of dose component discrimination method using micelle gel dosimeters for quality assurance in boron neutron capture therapy.

Determination of the half-life of 127Sb using the reference source method.

Evaluation of bismuth oxide nanoparticles for enhanced gamma-ray/neutron shielding in HDPE-based composites.