Cyclotron Facility Research Articles

Status of laser spectroscopy measurements of long-lived antiprotonic and pionic helium atoms at CERN and PSI

The results of laser spectroscopy experiments of antiprotonic helium atoms carried out at the Antiproton Decelerator of CERN, and pionic helium atoms measured at the 590[Formula: see text]MeV ring cyclotron facility of the Paul Scherrer Institute are reviewed. The former experiment determined the antiproton-to-electron mass ratio as [Formula: see text]. In the latter, a resonant transition [Formula: see text] of pionic helium at a frequency of [Formula: see text][Formula: see text]GHz was detected. Some future perspectives are briefly described.

Implementing a new cyclotron facility: challenges and opportunities for advancing PET/CT imaging in an isolated island setting

Implementing a new cyclotron facility: challenges and opportunities for advancing PET/CT imaging in an isolated island setting

Correction factors for induced radioactivity: comparing simplified continuous and periodic irradiation scenarios in medical cyclotron decommissioning.

The use of a Monte Carlo code in the assessment of residual radioactivity for decommissioning of a medical cyclotron facility requires a reasonable approximation to the facility's history of operations. A periodic irradiation scenario simulating the cyclotron's daily operation for radioisotope production is generally considered reasonable, but its implementation in the code's input file can be cumbersome because more than thousands of irradiation cycles must be modeled. In practice, two simplified scenarios with continuous irradiation are commonly used instead: (i) omitting the downtime between two irradiation periods and (ii) extending the irradiation duration across the entire operational lifespan of the facility, albeit with a reduced beam current to maintain workload consistency. A systematic comparison of residual radionuclide productions across various half-lives under these three scenarios was performed. This technical note presents the resulting correction factors for the two simplified continuous irradiation models, enhancing their applicability in estimating radioactive inventories under a range of circumstances.

Activation analysis of RFT-30 cyclotron target assembly

This work evaluated the validity of computer simulation codes by comparing the results of an inventory calculation for a89Zr target assembly with measured data obtained using a high-purity germanium detector. For the inventory calculation, the MCNP6 and FISAPCT-Ⅱ codes were used, and for the measurement, efficiency derived from the efficiency transfer method was used. The MCNP6's ENDF/B-Ⅶ library (TENDL-2017 library for 89Y) and the CEM03.03 physics model were employed to simulate proton reactions, while the ENDF/B-Ⅶ library alone was utilized for neutron reactions. To verify the efficiency obtained by the efficiency transfer method, the calculated activity of the reference sources was compared with the measured activity and confirmed to be within 11%. For the target assembly, the average calculated-to-measured activity (C/M) ratio was determined to be 0.7–2.0 (physics model) and 0.7–1.5 (data library with TENDL), thus confirming the validity of the computer simulation codes. The above results suggest that the methods presented in this study could be used to establish decommissioning plans for the cyclotron facility, including plans for waste disposal of cyclotron components such as target assemblies.

Development of a fast neutron monitoring detector for the NDPS neutron TOF facility by using Parallel Plate Avalanche Counters

A Parallel Plate Avalanche Counter (PPAC) neutron monitoring detector was developed and manufactured to monitor fast neutrons with energies greater than ∼1 MeV for use in the Nuclear Data Production System (NDPS), a neutron Time-of-Flight (TOF) facility of RAON. The detectors designed for monitoring fast neutrons comprise two sets of PPACs and a fast neutron converter. The performance of the detector was tested by using a241Am alpha source and neutron beams from a proton cyclotron. For the fast neutron converter, a thin thorium coating with a diameter of 60 mm was prepared by using the electrodeposition method. The areal density of thorium deposited on a thin aluminium layer with a thickness of 2 μm was determined by alpha spectrometry and measured to be 306 ± 7.65 μg/cm2. For the neutron beam test, neutrons were generated through the 9Be (p,n)9B reaction in a proton cyclotron facility. These generated neutrons were detected by using our PPAC neutron detector, and the experimentally measured count rate (1.74 ± 0.18 counts/s) agreed with the count rate (1.68 counts/s) calculated by PHITS v3.16 and GEANT4 v10.7 simulations. The timing resolution of the detector was estimated to be σ = 550 ps.

Chemical characterization of lithium based ceramics utilizing charged particle activation and ion beam techniques

Non-destructive methodologies using activation analysis and ion beam analysis techniques were optimized for the chemical characterization of ceramic materials, lithium titanate and lithium niobate, which have application in tritium breeding blanket. The analyses were carried out as a part of chemical quality control exercise. The atomic ratios of Li/Ti, Li/Nb were quantified by charged particle activation analysis using 13 MeV proton beam from variable energy cyclotron facility and particle induced gamma ray emission/Rutherford backscattering spectrometry using 3 MeV/2 MeV proton beam from 3MV tandem accelerator facility. The results of these different analytical methods are in good agreement, which established the applicability of these activation analysis and ion beam techniques for the chemical characterization of these ceramic materials.

Mandatory Requirements for Planning and Commissioning of Medical Cyclotron Facility.

Over the last 15 years, there has been substantial growth in the installation of medical cyclotrons. This is mainly due to the increased demand for the production of positron emission tomography radiopharmaceuticals. In every country, there is a regulatory body that regulates the uses of medical cyclotron intending to protect occupational workers, the public, and the environment. It regulates the entire stages of such facilities, which mainly controls regulatory activities such as construction, commissioning, operation, and decommissioning. This article primarily highlights the key practices for planning and installation of a medical cyclotron facility (MCF). It also covers the particular aspects that should be considered in the early stages of project planning and provides information for best practices and challenges. If these aspects are properly addressed, then it ensures the safe operation of the MCF. The texts also elaborate on the necessary requirements for effective planning of the MCF, such as layout and space considerations, workload plan and maximum research capacity of the institute and equipment, shielding requirements, water cooling circuit, storage of radioactive components, management of radioactive waste from medical cyclotron and radiochemistry laboratory, construction and commissioning project management, exhaust system and filtration options, plans for staffing and training, and combination of equipment safety systems and building safety systems.

Radiosynthesis and Quality Control of [18F] PSMA-1007 at the Cyclotron Facility of National Institute of Nuclear Medicine and Allied Sciences (NINMAS) for Diagnosis of Prostate Cancer

Radiosynthesis and Quality Control of [18F] PSMA-1007 at the Cyclotron Facility of National Institute of Nuclear Medicine and Allied Sciences (NINMAS) for Diagnosis of Prostate Cancer

OPTIma: simplifying calorimetry for proton computed tomography in high proton flux environments

Objective. Proton computed tomography (pCT) offers a potential route to reducing range uncertainties for proton therapy treatment planning, however the current trend towards high current spot scanning treatment systems leads to high proton fluxes which are challenging for existing systems. Here we demonstrate a novel approach to energy reconstruction, referred to as ‘de-averaging’, which allows individual proton energies to be recovered using only a measurement of their integrated energy without the need for spatial information from the calorimeter. Approach. The method is evaluated in the context of the Optimising Proton Therapy through Imaging (OPTIma) system which uses a simple, relatively inexpensive, scintillator-based calorimeter that reports only the integrated energy deposited by all protons within a cyclotron period, alongside a silicon strip based tracking system capable of reconstructing individual protons in a high flux environment. GEANT4 simulations have been performed to examine the performance of such a system at a modern commercial cyclotron facility using a σ ≈ 10 mm beam for currents in the range 10–50 pA at the nozzle. Main results. Apart from low-density lung tissue, a discrepancy of less than 1% on the Relative Stopping Power is found for all other considered tissues when embedded within a 150 mm spherical Perspex phantom in the 10–30 pA current range, and for some tissues even up to 50 pA. Significance. By removing the need for the calorimeter system to provide spatial information, it is hoped that the de-averaging approach can facilitate clinically relevant, cost effective and less complex calorimeter systems for performing high current pCTs.

44Sc production from enriched 47TiO2 targets with a medical cyclotron

44Sc is a β+-emitter which has been extensively studied for nuclear medicine applications. Its promising decay characteristics [t1/2 = 3.97 h, Eβ+ = 632 keV (94.3%), Eγ = 1157 keV (99.9%); 1499 keV (0.91%)] make it highly attractive for clinical PET imaging, offering an alternative to the widely used 68Ga [t1/2 = 67.7 min, Eβ+ = 836 keV (87.7%)]. Notably, its nearly fourfold longer half-life opens avenues for applications with biomolecules having extended biological half-lives and enables the centralized distribution of 44Sc radiopharmaceuticals. An additional advantage of employing 44Sc as a diagnostic radioisotope lies in its counterpart, the β−-emitter 47Sc, which is currently under investigation for targeted radiotherapy. Together, they form an ideal theranostic pair, providing a comprehensive solution for both diagnostic imaging and therapeutic applications in nuclear medicine.At the Bern medical cyclotron, a study to optimize the production of scandium radioisotopes is currently ongoing. In this context, proton irradiation of titanium targets has been investigated, exploiting the reactions 47Ti(p,α)44Sc and 50Ti(p,α)47Sc. This approach enables the production of Sc radioisotopes within a single PET medical cyclotron facility, employing identical chemical procedures for target preparation and post-irradiation processing.In this paper, we report on cross-section measurements of the 47Ti(p,α)44Sc nuclear reaction using 95.7% enriched 47TiO2 targets. On the basis of the obtained results, the production yield and purity were calculated to assess the optimal irradiation conditions. Production tests were performed to confirm these findings.

Radioprotection in the production of 18F-FDG at Brazilian cyclotron facilities: A comparative study based on dosimetry

Since the end of the Brazilian state monopoly in 2006, allowing private enterprises to act in producing and commercializing short half-life radiopharmaceuticals, the country observed a growth in the laboratories that use 18F-FDG to PET/CT exams. Considering the radiological protection and safety techniques applied to radioisotope-producing facilities or units, this study assembled the current situation of radiological protection showing the received doses of the professionals of four facilities with cyclotrons for 18F-FDG located in south and southeast Brazil in the years 2020 and 2021. The dose values observed are below the dose limits established by national and international regulatory entities but can still be optimized considering differences between the production units.

An irradiation system for nuclear and materials research in a medical cyclotron

Development and commissioning of an irradiation system and experimental setup for nuclear research and materials analysis in a medical cyclotron facility is described. The setup, Low Energy in-Vacuum Irradiation System-LEVIS, is installed at the end of the existing R&D beamline. The components of LEVIS and their functions are explained and the characteristics such as energy, current and profile of the beam are measured. Different types of radiation detectors are installed and tested in the chamber for future applications of non-destructive analysis methods.

Comparing the effects of various (p,xn) radionuclide production routes on induced radioactivity in the concrete walls of a cyclotron vault.

In sum, 11 (p,xn) related nuclear reactions with 9 target materials, namely 18O(p,n)18F, 15N(p,n)15O, 68Zn(p,n)68Ga, 68Zn(p,2n)67Ga, 69Ga(p,2n)68Ge, 89Y(p,n)89Zr, 100Mo(p,pn)99Mo, 100Mo(p,2n)99mTc, 112Cd(p,2n)111In, 124Xe(p,2n)123Cs and 203Tl(p,3n)201Pb, are involved in the operation of 13 radionuclide-production cyclotrons in Taiwan. The secondary neutrons accompanying these production routes could induce varying degrees of material activation in the cyclotron facility. Accordingly, this study compared the effects of various (p,xn) production routes on the neutron-induced long-lived radioactivity in the concrete walls of a hypothetical cyclotron vault. In addition, an activation-reduction approach involving the addition of a layer of neutron-absorbing material to the surface of inner concrete walls was evaluated.

Study of terbium production from enriched Gd targets via the reaction 155Gd(d,2n)155Tb

The terbium (Tb) family has attracted much attention in recent years thanks to the diagnostic and therapeutic applications of the quadruplet 149Tb, 152Tb, 155Tb and 161Tb. However, the scarce availability of Tb radioisotopes is one of the main reasons hindering its clinical applications. To increase its availability, this work proposes to use enriched gadolinium (Gd) targets to produce some Tb radioisotopes (149Tb, 152Tb, and 155Tb) via deuteron-induced reactions in cyclotrons. The production of the Auger and gamma emitter 155Tb was chosen as a case study because the 155Gd enrichment (92.8%) is the highest available from all Gd stable isotopes. The involved reaction is 155Gd(d,2n)155Tb. Using enriched thin Gd-containing targets, cross-sections of the reactions 155Gd(d,x)153,154,155,156Tb have been measured at the GIP ARRONAX cyclotron facility with a beam energy ranging from 8 MeV to 30 MeV. This measurement allows for estimating the production yield and the purity of 155Tb, and for determining the irradiation parameters for large production batches. A thick enriched 155Gd2O3 target has been then irradiated with an incident energy of 15.1 MeV and a beam current of 368 nA for 1 h. The production yield of 155Tb is 10.2 MBq/μA/h at End Of Bombardment (EOB) and the purity is 89% after 14 days of decay. These experimental values are consistent with estimation based on measured cross-sections. A comparison of the deuteron-induced and proton-induced production routes is also presented in this paper.

РАДИАЦИОННЫЕ ИСТОЧНИКИ И ДОЗЫ ОБЛУЧЕНИЯ ПЕРСОНАЛА И ПАЦИЕНТОВ ПЭТ-ЦЕНТРА

Introduction 1. Emissions in cyclotron facility and their influence on staff 2. Radiation sources of radiochemical laboratory and radiation exposure of radiochemists 3. Ionizing radiation sources in PET diagnostics division and doses of medical staff 4. Doses of PET center patients Conclusion

A Radiation Levels Measurement at Workplace of Cyclotron-PET/CT Facilities (in Karachi) using TLD Dosimeters

Cyclotron is the most widely used proton particle accelerator for production of short lived radionuclides particularly F-18 for diagnostic purpose in oncology imaging. Currently, only Fluorine [F-18] is being produced in Pakistan. F-18 is tagged with glucose analogue and converted into [18F] FDG (Fluorodeoxyglucose) by synthesis process. [18F] FDG emits positron and, via annihilation process, produces two gamma photons of 511keV energy, which is of great concern for occupational safety. Therefore, a study was carried out to assess the dose incurred by radiation workers working in controlled and supervised areas of cyclotron facility.
 In this study, the ten (10) calibrated Thermoluminescene dosimeters (TLD-100) were annealed and placed in different locations of four Cyclotron-PET/CT facilities for determination of dose in work area. In the selected cyclotron facilities, one out of four was unshielded cyclotron and other three were self-shielded. Ten (10) TLDs were placed in preselected controlled and supervised areas of facilities for the duration of 30 days. After four weeks of exposure, TLDs were removed and assessed on TLD reader for dose evaluation.
 The evaluated results of radiation levels from TLDs are in good agreement with the criteria for classification of areas as defined in Regulations on Radiation Protection (PAK/904). The measured doses of work area are well below the defined regulatory dose limits for controlled area (>6mSv/yr) as well as supervised area (>1mSv/yr) except in case of unshielded cyclotron vault. It is concluded that the facilities have implemented the requirement 27 of PNRA Regulations on Radiation Protection (PAK/904) and also have established strong radiation safety measures for minimization of occupational exposure.

Production of cobalt-57 for industrial and medical applications in RFT-30 cyclotron facility

Production of cobalt-57 for industrial and medical applications in RFT-30 cyclotron facility

The new Batch Mode Ion Source for stand-alone operation at the Facility for Rare Isotope Beams (FRIB)

Gas stoppers have been used for a long-standing successful science program at Michigan State University with stopped and rare-isotope beams produced by projectile fragmentation. The National Superconducting Cyclotron Laboratory’s Coupled Cyclotron Facility has recently transitioned into the Facility for Rare Isotope Beams (FRIB) laboratory to provide rare isotopes using a high-power superconducting linear accelerator and new production facilities. To allow the science program with stopped and reaccelerated beams to continue during the transition period, a stand-alone capability was added. The Batch Mode Ion Source (BMIS) was built and has been providing beams of long-lived and stable isotopes of a variety of elements for successful user experiments. The BMIS system is described and results from the production of various beams are presented.

Ionizing Radiation in PET Center and Level of Their Exposure on Personnel and Patients

CONTENTS
 Introduction
 1. Dose rate of gamma and neutron radiation in the cyclotron facility
 2. Ionizing radiation in radiochemical laboratory and personnel doses
 3. Radiation sources in PET department and their contribution in personnel radiation exposure
 4. Doses of patients under performance of PET/CT study
 Summary

Annual whole-body occupational radiation exposure in the medical and industrial fields in Saudi Arabia

The monitoring of radiation workers’ (RWs) occupational doses resulting from working in different applications is essential to comply with the recommended dose limit (20 mSv) and to establish a reference level for the annual occupational dose. In Saudi Arabia, a national project to assess the occupational doses in different occupations has been conducted, in which several studies have been published. This study is intended to review these studies and compiles the annual occupational doses – in terms of the whole-body effective dose. The project included the thermoluminescent dosimeter (TLD) records of 57 898 RWs in the medical and industrial fields. The RWs in the medical field included workers in diagnostic radiology (DR), nuclear medicine (NM), radiotherapy (RT), dentistry (Dent.), interventional radiology (IR), and operating rooms (OR). The RWs in the industrial field included workers for phosphate mining (PM), workers in the pavement construction (PC), and workers in cyclotron facilities (CF). The TLDs records were collected and analysed to assess the annual occupational dose – in terms of mean annual effective dose (AMED). The AMED ± SD was 0.88 ± 0.56 mSv for DR, 1.22 ± 1.01 mSv for NM, 0.73 ± 0.47 mSv for RT, 0.78 ± 0.47 mSv for Dent., 0.95 ± 0.61 mSv for IR, 0.59 ± 0.44 mSv for OR, 0.80 ± 0.46 mSv for PC, 0.66 ± 0.45 mSv for PM, and 1.60 ± 1.46 mSv for CF. The results showed significant differences in the AMEDs among the workers (p = 0.001). The highest AMEDs in the medical and industrial fields were those of NM and CF workers, respectively. However, the AMEDs for the RWs in both fields were below the annual recommended occupational dose limit and 72% were below the public dose limit (1 mSv). UNSCEAR conducts evaluations of worldwide occupational exposure to provide a reliable and comprehensive estimate of worldwide dose distributions and trends. UNSCEAR’s last evaluation of occupational exposure was in 2002; however, the report did not provide any information about Saudi Arabia. Updating information on occupational exposure in these reports is important to reflect worldwide practices in radiation work environments. Therefore, this paper can serve as a source of information for international efforts, such as those encouraged by UNSCEAR.