The ISOLDE facility Catherall, R; Andreazza, W; Breitenfeldt, M ...
Journal of physics. G, Nuclear and particle physics,
09/2017, Letnik:
44, Številka:
9
Journal Article
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The ISOLDE facility has undergone numerous changes over the last 17 years driven by both the physics and technical community with a common goal to improve on beam variety, beam quality and safety. ...Improvements have been made in civil engineering and operational equipment while continuing developments aim to ensure operations following a potential increase in primary beam intensity and energy. This paper outlines the principal technical changes incurred at ISOLDE by building on a similar publication of the facility upgrades by Kugler (2000 Hyperfine Interact. 129 23-42). It also provides an insight into future perspectives through a brief summary issues addressed in the HIE-ISOLDE design study Catherall et al (2013 Nucl. Instrum. Methods Phys. Res. B 317 204-207).
Since its commissioning in December 2017, the CERN-MEDICIS facility has been providing non-conventional radionuclides for research in nuclear medicine. Benefitting from decades of experience in the ...production of radioactive ion beams and in the mass separation process from the ISOLDE facility at CERN, MEDICIS quickly became a worldwide key player in the supply of novel medical isotopes dedicated to research in the fields of cancer imaging, diagnostics, and radiation therapy.
After a few years of operation, successful collections have been performed on a large panel of radionuclides such as 128Ba, 149,152,155Tb, 153Sm, 165,167Tm, 169Er, 175Yb, 191Pt, and 225,227Ac. Several milestones have been achieved on the output of the facility, such as the collection of 0.5 GBq of 175Yb, and a total separation efficiency higher than 50% reached for 167Tm in 2020. These collections led to notable recent in-vitro and preclinical results in targeted radionuclide therapy achieved with high molar activity 175Yb and 153Sm products.
Constant developments are ongoing, such as innovative target designs, molecular formation to improve the release of some specific isotopes, laser development in the dedicated MELISSA laboratory, study of new implantation foil materials, and post-collection radiochemistry.
Abstract
CERN-MEDICIS is an isotope mass separation facility dedicated to biomedical research located in a type A work sector, receiving on average 50% of the 1.4 GeV protons delivered by the Proton ...Synchrotron Booster (PSB). It was commissioned with Radioactive Ion Beams (RIB’s) in 2017. MEDICIS has operated for the past 5 years in batch mode, with targets irradiated in a station located at the HRS beam dump, and with external sources provided by MEDICIS cyclotrons and nuclear reactors partners, notably during the Long Shutdown (LS2). Additional features of the facility include the MELISSA laser ion source, radiochemistry on implanted radionuclides and an online gamma-ray spectroscopy implantation monitoring. In 2022, we introduced Key Performance Indicators (KPI’s) to monitor the operation of the facility for collected efficiencies, the optimisation of the radiological risks and evaluate impact of possible modifications of the station, paralleling for instance LHC’s integrated luminosity. Defined KPI’s cover aspects in the operation cycle, e.g. planning in CERN schedule, target irradiations, duration of the process, radiological risk mitigation, facility up-time, developments and maintenance. MEDICIS KPI’s can help distinguish which of the operation and infrastructure life cycle requires immediate intervention, developments or consolidation. Those are related to the irradiation stations and irradiation possibilities, the beamlines (parallel collections), target and ion sources (reliability), robot handling and infrastructure, or the separation process itself.
The HIE-ISOLDE project aims at expanding the physics programme of the ISOLDE facility at CERN. In particular, the addition of a superconducting linac will allow the post-acceleration of radioactive ...ion beams up to 10 MeV/u. However, because of field emission in the superconducting cavities and the possibility of neutron production for ion interactions above the Coulomb barrier, new radiological hazards need to be mitigated. Measurements of dose rate levels close to cavity prototypes were used to determine the intensity of the source of X ray due to field emission for a single cavity. The results were extrapolated to the operation of the 32 cavities that will be installed, and a detailed FLUKA calculation was performed to determine the required shielding to minimise the exposure of personnel present in the ISOLDE experimental hall during operation. FLUKA was also used to determine the maximum ambient dose equivalent rate levels in the accessible part of the hall due to ion beam losses for the envelope energies and intensities.
The high intensity and energy ISOLDE (HIE-ISOLDE) project is an upgrade to the existing ISOLDE facility at CERN. The foreseen increase in the nominal intensity and the energy of the primary proton ...beam of the existing ISOLDE facility aims at increasing the intensity of the produced radioactive ion beams (RIBs). The currently existing ISOLDE facility uses the proton beam from the proton-synchrotron booster with an energy of 1.4 GeV and an intensity up to 2 μA. After upgrade (final stage), the HIE-ISOLDE facility is supposed to run at an energy up to 2 GeV and an intensity up to 4 μA. The foreseen upgrade imposes constrains, from the radiation protection and the radiation safety point of view, to the existing experimental and supply areas. Taking into account the upgraded energy and intensity of the primary proton beam, a new assessment of the radiation protection and radiation safety of the HIE-ISOLDE facility is necessary. Special attention must be devoted to the shielding assessment of the beam dumps and of the experimental areas. In this work the state-of-the-art Monte Carlo particle transport simulation program FLUKA was used to perform the computation of the ambient dose equivalent rate distribution and of the particle fluxes in the projected HIE-ISOLDE facility (taking into account the upgrade nominal primary proton beam energy and intensity) and the shielding assessment of the facility, with the aim of identifying in the existing facility (ISOLDE) the critical areas and locations where new or reinforced shielding may be necessary. The consequences of the upgraded proton beam parameters on the operational radiation protection of the facility were studied.
The ISOLDE facility at CERN is one of the first facilities in the world dedicated to the production of the radioactive ion beams (RIB) and during all its working time underwent several upgrades. The ...goal of the latest proposed upgrade, 'The High Intensity and Energy ISOLDE' (HIE-ISOLDE), is to provide a higher performance facility in order to approximate it to the level of the next generation ISOL facilities, like EURISOL. The HIE-ISOLDE aims to improve significantly the quality of the produced RIB and for this reason the increasing of the primary beam power is one of the main objectives of the project. An increase in the nominal beam current (from 2 to 6 μA proton beam intensity) and energy (from 1.4 GeV to 2 GeV) of the primary proton beam will be possible due to the upgrade of CERN's accelerator infrastructure. The current upgrade means reassessment of the radiation protection and the radiation safety of the facility. However, an evaluation of the existing shielding configuration and access restrictions to the experimental and supply areas must be carried out. Monte Carlo calculations were performed in order to evaluate the radiation protection of the facility as well as radiation shielding assessment and design. The FLUKA-Monte Carlo code was used in this study to calculate the ambient dose rate distribution and particle fluxes in the most important areas, such as the experimental hall of the facility. The results indicate a significant increase in the ambient dose equivalent rate in some areas of the experimental hall when an upgrade configuration of the primary proton beam is considered. Special attention is required for the shielding of the target area once it is the main and very intensive radiation source, especially under the upgrade conditions. In this study, the access points to the beam extraction and beam maintenance areas, such as the mass separator rooms and the high voltage room, are identified as the most sensitive for the experimental hall from the radiation protection point of view.
We report on the measurement of the ^{7}Be(n,p)^{7}Li cross section from thermal to approximately 325 keV neutron energy, performed in the high-flux experimental area (EAR2) of the n_TOF facility at ...CERN. This reaction plays a key role in the lithium yield of the big bang nucleosynthesis (BBN) for standard cosmology. The only two previous time-of-flight measurements performed on this reaction did not cover the energy window of interest for BBN, and they showed a large discrepancy between each other. The measurement was performed with a Si telescope and a high-purity sample produced by implantation of a ^{7}Be ion beam at the ISOLDE facility at CERN. While a significantly higher cross section is found at low energy, relative to current evaluations, in the region of BBN interest, the present results are consistent with the values inferred from the time-reversal ^{7}Li(p,n)^{7}Be reaction, thus yielding only a relatively minor improvement on the so-called cosmological lithium problem. The relevance of these results on the near-threshold neutron production in the p+^{7}Li reaction is also discussed.
Scandium (Sc) has gained significant interest in nuclear medicine due to its 43Sc, 44g/mSc, and 47Sc radioactive isotopes being suitable for cancer diagnostics and therapy, offering a promising ...avenue for theranostics. Various production methods, including irradiation of enriched or naturally abundant calcium (Ca), titanium (Ti), and vanadium (V) materials with different particle beams, have been investigated to produce 43Sc, 44g/mSc, and 47Sc. However, challenges persist in achieving high molar activity and radiochemical purity for medical applications. The physical isotope mass separation technique presents an alternative, obviating the need for enriched target materials by inherently isolating Sc isotopes during the separation process. Despite recent advancements in Sc mass separation at different facilities, efficiency and yield remain sub-optimal for medical dose production. This study aims to systematically investigate the thermal release kinetics of Sc radionuclides from activated natural titanium foils in tantalum (Ta) environments of ISOL (Isotope Separation On-Line) target units. By elucidating the combination of target material structure and temperature conditions, enhanced release parameters were identified. Maximum Sc release from a non-embossed natTi foil samples was achieved at 1200 °C, for embossed natTi foil samples at 1450 °C and for natV foil samples at 1600 °C, within an hour of reaching the set temperature. These findings offer insights into optimizing the mass separation process to improve the efficiency in Sc radionuclide production for medical applications.
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