Ultra-pure Nickel for Structural Components of Low-Radioactivity Instruments
Abstract
The next generation of rare-event search experiments in nuclear and particle physics demand structural materials combining exceptional mechanical strength with ultra-low levels of radioactive contamination. This study evaluates chemical vapor deposition (CVD) nickel as a candidate structural material for such applications. Manufacturer-supplied CVD Ni grown on aluminum substrates underwent tensile testing before and after welding alongside standard Ni samples. CVD Ni exhibited a planar tensile strength of ~600 MPa, significantly surpassing standard nickel. However, welding and heat treatment were found to reduce the tensile strength to levels comparable to standard Ni, with observed porosity in the welds likely contributing to this reduction. Material assay via inductively coupled plasma mass spectrometry (ICP-MS) employing isotope-dilution produced measured bulk concentration of 232-Th, 238-U, and nat-K at the levels of ~70 ppq, <100 ppq, and ~900 ppt, respectively, which is the lowest reported in nickel. Surface-etch profiling uncovered higher concentrations of these contaminants extending ~10 micrometer beneath the surface, likely associated with the aluminum growth substrate. The results reported are compared to the one other well documented usage of CVD Ni in a low radioactive background physics research experiment and a discussion is provided on how the currently reported results may arise from changes in CVD fabrication or testing process. These results establish CVD Ni as a promising low-radioactivity structural material, while outlining the need for further development in welding and surface cleaning techniques to fully realize its potential in large-scale, low radioactive background rare-event search experiments.
Keywords
Cite
@article{arxiv.2508.08230,
title = {Ultra-pure Nickel for Structural Components of Low-Radioactivity Instruments},
author = {T. J. Roosendaal and C. T. Overman and G. S. Ortega and T. D. Schlieder and N. D. Rocco and L. K. S. Horkley and K. P. Hobbs and K. Harouaka and J. L. Orrell and P. Acharya and A. Amy and E. Angelico and A. Anker and I. J. Arnquist and A. Atencio and J. Bane and V. Belov and E. P. Bernard and T. Bhatta and A. Bolotnikov and J. Breslin and P. A. Breur and J. P. Brodsky and E. Brown and T. Brunner and B. Burnell and E. Caden and L. Q. Cao and D. Cesmecioglu and S. A. Charlebois and D. Chernyak and M. Chiu and T. Daniels and L. Darroch and R. DeVoe and M. L. di Vacri and M. J. Dolinski and B. Eckert and M. Elbeltagi and A. Emara and W. Fairbank and B. T. Foust and D. Gallacher and N. Gallice and W. Gillis and A. Gorham and G. Gratta and C. A. Hardy and S. C. Hedges and M. Heffner and E. Hein and J. D. Holt and A. Iverson and A. Karelin and I. V. Kotov and A. Kuchenkov and A. Larson and M. B. Latif and S. Lavoie and K. G. Leach and B. G. Lenardo and D. S. Leonard and K. K. H. Leung and H. Lewis and X. Li and Z. Li and C. Licciardi and R. Lindsay and R. MacLellan and S. Majidi and C. Malbrunot and M. Marquis. J. Masbou and M. Medina-Peregrina and S. Mngonyama and B. Mong and D. C. Moore and X. E. Ngwadla and K. Ni and A. Nolan and S. C. Nowicki and J. C. Nzobadila Ondze and A. Odian and L. Pagani and H. Peltz Smalley and A. Pena-Perez and A. Piepke and A. Pocar and S. Prentice and V. Radeka and R. Rai and H. Rasiwala and D. Ray and S. Rescia and G. Richardson and V. Riot and R. Ross and P. C. Rowson and R. Saldanha and S. Sangiorgio and S. Sekula and T. Shetty and L. Si and J. Soderstrom and F. Spadoni and V. Stekhanov and X. L. Sun and S. Thibado and T. Totev and S. Triambak and R. H. M. Tsang and O. A. Tyuka and E. van Bruggen and M. Vidal and M. Walent and Y. G. Wang and Q. D. Wang and M. P. Watts and M. Wehrfritz and L. J. Wen and S. Wilde and M. Worcester and X. M. Wu and H. Xu and H. B. Yang and L. Yang and O. Zeldovich},
journal= {arXiv preprint arXiv:2508.08230},
year = {2025}
}