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Low Energy Particle Accelerators and Laboratories
Published in Vlado Valković, Low Energy Particle Accelerator-Based Technologies and Their Applications, 2022
NEC provides industry-leading electrostatic ion beam accelerator systems and related components designed to expand the research goals of scientific and technical communities around the world. A private, employee-owned company, NEC was incorporated in Middleton, Wisconsin in 1965. To date, NEC has manufactured over 230 Pelletron systems, with their installations in over 50 countries around the world. These systems produce ion beams of essentially all stable nuclei with energies ranging from a few keV to hundreds of MeV. The Pelletron is the world's only commercially available accelerator that incorporates an all metal and ceramic acceleration tube, with no organic material in the vacuum volume (some of the models are shown in Figs. 1.34–1.38).
Ferrous Sulfate–Benzoic Acid–Xylenol Orange Chemical Dosimetry System in Radiotherapy
Published in Pandit B. Vidyasagar, Sagar S. Jagtap, Omprakash Yemul, Radiation in Medicine and Biology, 2017
Manoj K. Semwal, Pandit B. Vidyasagar
The irradiation experiment was carried out at 15 UD Pelletron (16 MV Van de Graff machine) facility of the Nuclear Science Centre, New Delhi with 1 cm diameter carbon-12 beam. One of the improvisations required to carry out the experiment was to devise a technique for irradiation as the radiation beam from the Pelletron emerges horizontally. Further, the 55 MeV carbon beams that were available from the machine had a range of approximately 115 μm in water and hence the wall of container used for irradiation was required to be very thin to avoid attenuation to the beam in the wall itself. The LET for this beam in water as calculated by TRIM 98.0 Monte Carlo code varies from about 300 KeV/μm at the entrance to reaching a maximum value of about 800 KeV/ μm at 100 μm depth before the beam is completely stopped. Any irradiation vial to hold the FBX solution should have a wall thickness considerably less than 115 μm. A pilot experiment with 20 mL glass bottles was done to test the feasibility of the procedure. The sidewalls of the bottles had plane surfaces. For beam entry, a hole of approximately 2 cm diameter was cut on one of the sidewalls of the bottles. The hole was then covered with a 6 polypropylene sheet with the help of glue. During irradiation, the solution was continuously stirred with a magnetic stirrer to homogenize the dose in the solution. The results obtained with this technique were not reproducible and also the dose and corresponding optical density values showed no relationship. Clearly the uncertainties associated with the experiment overshadowed the dose response pattern. We believe that among the many reasons for such an outcome, contamination of the solution with the glue used to paste the polypropylene sheet and non-homogeneous dose distribution in the solution owing to a large volume of the solution were the most important ones. Moreover, time taken to deliver doses relevant for our experiment (few cGy to few tens of cGy) to the solution was very long due to large volume of the solution and low particle flux (103–104 particles cm−2 s−1) achievable from the Pelletron.
Dental fluorosis in the Vesuvius towns in AD 79: a multidisciplinary approach
Published in Annals of Human Biology, 2019
Pierpaolo Petrone, Vincenzo Graziano, Chaturvedula Sastri, Thierry Sauvage, Marcello Mezzasalma, Mariano Paternoster, Fabio Maria Guarino
Fluoride (F) concentration was determined both in the enamel and in the dentine by Particle Induced Gamma-ray Emission (PIGE) technique (Sastri et al. 2013). The F determination is based on 19F(p,p′γ) 19F reaction and 197 keV γ-ray was used for its identification. The experiments were done with the 3 MV pelletron at CNRS-CEMHTI (Orleans, France). A full description of the experimental set-up is given in Sastri et al. (2001). Irradiations were performed with 2.5 MeV protons at currents < 10 nA (for teeth) and the charge collected was 1–5 µC depending on F count rate. Each sample was irradiated at different spots: two in the case of enamel and from two to five in the case of dentine, depending on the quality of the ground section (Figure 1A and B). The tooth sections were treated as ‘thick targets’ for irradiation with 2.5 MeV protons. F content was measured as ppm values and given as mean ± SD.
Absorption, disposition and metabolic pathway of amiselimod (MT-1303) in healthy volunteers in a mass balance study
Published in Xenobiotica, 2019
Takayuki Kifuji, Shinsuke Inoue, Megumi Furukawa, Begonya Perez Madera, Takahiro Goto, Hiroshi Kumagai, Stuart J Mair, Atsuhiro Kawaguchi
The prepared HPLC plasma samples were injected into the HPLC column, and the eluate was fractionated every 18 s from 66 to 78 min after the start of analysis to collect MT-1303 and MT-1303-P. The obtained fractions were analysed by AMS (NEC 1.5SDH-1, 0.6 MV Pelletron AMS system, National Electrostatics Corp). The retention times of MT-1303 and MT-1303-P were confirmed by measurement of the reference standard mixture before fractionation.PPM sample: the HPLC eluate was fractionated every 18 s from 0 to 135 min, and each fraction obtained was measured by AMS.Plasma sample (at each time point): the HPLC eluate was fractionated every 18 s from 66 to 78 min, and each fraction obtained was measured by AMS. Plasma samples were measured to calculate the PK parameters for MT-1303 and MT-1303-P.0–240 h urine sample: the HPLC eluate was fractionated every 18 s from 0 to 135 min. Each fraction obtained from 0 to 80.1 min was measured by AMS. Fractions obtained from 80.1 to 135 min were mixed in equal amounts, and the mixture was then measured by AMS.1344–1368 h urine sample: the HPLC eluate was fractionated every 18 s from 0 to 135 min. Each fraction obtained from 65.1 to 80.1 min was measured by AMS. Fractions obtained from 0 to 65.1 min and from 80.1 to 135 min were mixed in equal amounts, and the respective mixtures were then measured by AMS.0–240 h faeces sample: the HPLC eluate was fractionated every 18 s from 0 to 135 min, and each fraction obtained was measured by LSC.1344–1368 h faeces sample: the sample was processed in the same manner as for the 1344–1368 h urine sample.