Speaker
Description
Silicon carbide (SiC) has historically been employed as a target material at ISOLDE (CERN) [1] and ISAC (TRIUMF) [2] and is currently under evaluation and development at emerging facilities including ISOL@MYRRHA (SCK CEN) [3] and SPES (INFN) [4]. Thanks to its high thermal conductivity, excellent emissivity, and chemical stability at elevated temperatures, SiC is under investigation for developing towards a material.
In the framework of the MYRRHA Phase-1 project [5], SCK CEN is focusing on the development of SiC targets to produce Al and Mg isotopes. A collaborative effort with the ISOLDE Target and Ion Source Development (TISD) team has been initiated to support the upcoming production of F17 beams, of particular interest for the COLLAPS [6] experiment.
Five different SiC powder samples, pre-selected by the TISD team, were characterized at SCK CEN using Scanning Electron Microscopy (SEM), Energy Dispersive X-ray Spectroscopy (EDS), and Wavelength Dispersive X-ray Fluorescence (WDXRF). Based on microstructural analysis, two powders were identified as promising candidates due to their submicron grain sizes (<0.6 µm), which, as reported in literature [7], promote the diffusion of the produced isotopes though the grains. Nevertheless, the presence of aluminum impurities poses a limitation for both Al and F beam production. To mitigate this, fluorination treatments are being applied to the SiC pellets to reduce impurity levels prior to offline and online tests.
Subsequent sintering tests are planned post-fluorination to assess the thermo-mechanical stability of the material under irradiation-relevant conditions (1600–1700°C). The final target assembly is scheduled to be deployed in the mentioned COLLAPS experiment at ISOLDE by the end of November 2025.
[1] S. Fernandes, R. Catherall, G. izquierdo, J. Lettry, M. Menna, S. Sgobba, T. Stora, EURISOL Task3 workgroup, "Diffusion studies in prospective polycrystalline silicon carbide target materials".
[2] M. Dombsky, T. Achtzehn, P. Bricault, G. Hackman, V. Hanemaayer, J. Lassen, J. Lavoie, A.C. Morton, M. Pearson, E. Prime, M. Smith "Development of a high intensity 26gAl beam from SiC targets for accelerated beam experiments at ISAC," Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, vol. 264, no. 1, pp. 117-124, 2007.
[3] L. Popescu, D. Houngbo, M. Dierckx "High-power target development for the next-generation ISOL facilities," Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, vol. 463, pp. 262-268, 2020.
[4] L. Silvestroni, S. Corradetti, M. Marzolaro, M. Ballan, D. Cesarotto, D. Sciti, L. Zoli, "Novel SiC/C composite targets for the production of radioisotopes for," Journal of the European Ceramic Society, pp. 6750-6756, 2022.
[5] "https://www.sckcen.be/en/infrastructure/myrrha/myrrha-phase-1-minerva," [Online].
[6] “https://isolde.cern/collaps, [Online].
[7] S. Fernandes, “Submicro- and Nano-Structured Porous Materials for Production of High-Intensity Exotic Radioactive Ion Beams”, 2010.