Skip to main content
SpringerLink
Log in

Production and chemical separation of 229Pa toward observation of γ rays of 229mTh

  • Published:
Journal of Radioanalytical and Nuclear Chemistry Aims and scope Submit manuscript

Abstract

To observe the γ rays emitted from the low-lying isomeric state of 229Th (229mTh), we aim to dope fluoride crystals with its precursor 229Pa. In this study, we produced 229Pa by a 30 MeV proton bombardment on 232Th and developed a chemical separation method. The chemical yield of Pa was 93(4)%, and the physical production yield of 229Pa for the proton energy range of 29.0–30.1 MeV was measured to be 9.4(8) MBq/µAh, which was more than 10 times higher than those of 232,230,228,233Pa. These high chemical and production yields will allow us to prepare fluoride crystals having a sufficient amount of 229Pa for the observation of the γ rays of 229mTh.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Fig. 1
Fig. 2
Fig. 3

Similar content being viewed by others

References

  1. Seiferle B, von der Wense L, Bilous PV et al (2019) Energy of the 229Th nuclear clock transition. Nature 573:243–246

    Article  CAS  PubMed  Google Scholar 

  2. Sikorsky T, Geist J, Hengstler D et al (2020) Measurement of the 229Th isomer energy with a magnetic microcalorimeter. Phys Rev Lett 125:142503

    Article  CAS  PubMed  Google Scholar 

  3. Yamaguchi A, Muramatsu H, Hayashi T et al (2019) Energy of the 229Th nuclear clock isomer determined by absolute γ -ray energy difference. Phys Rev Lett 123:222501

    Article  CAS  PubMed  Google Scholar 

  4. Beck BR, Becker JA, Beiersdorfer P et al (2007) Energy splitting of the ground-state doublet in the nucleus 229Th. Phys Rev Lett 98:142501

    Article  CAS  PubMed  Google Scholar 

  5. Peik E, Tamm C (2003) Nuclear laser spectroscopy of the 3.5 eV transition in Th-229. Europhys Lett 61:181–186

    Article  CAS  Google Scholar 

  6. Campbell CJ, Radnaev AG, Kuzmich A et al (2012) Single-ion nuclear clock for metrology at the 19th decimal place. Phys Rev Lett 108:120802

    Article  CAS  PubMed  Google Scholar 

  7. Peik E, Schumm T, Safronova MS et al (2021) Nuclear clocks for testing fundamental physics. Quantum Sci Technol 6:034002

    Article  Google Scholar 

  8. Flambaum VV (2006) Enhanced effect of temporal variation of the fine structure constant and the strong interaction in 229Th. Phys Rev Lett 97:092502

    Article  CAS  PubMed  Google Scholar 

  9. von der Wense L, Seiferle B, Laatiaoui M et al (2016) Direct detection of the 229Th nuclear clock transition. Nature 533:47–51

    Article  PubMed  Google Scholar 

  10. Seiferle B, von der Wense L, Thirolf PG (2017) Lifetime measurement of the 229Th nuclear isomer. Phys Rev Lett 118:042501

    Article  PubMed  Google Scholar 

  11. Thielking J, Okhapkin MV, Głowacki P et al (2018) Laser spectroscopic characterization of the nuclear-clock isomer 229mTh. Nature 556:321–325

    Article  CAS  PubMed  Google Scholar 

  12. Tkalya EV, Schneider C, Jeet J, Hudson ER (2015) Radiative lifetime and energy of the low-energy isomeric level in 229Th. Phys Rev C 92:054324

    Article  Google Scholar 

  13. Minkov N, Pálffy A (2017) Reduced transition probabilities for the gamma decay of the 7.8 eV isomer in 229Th. Phys Rev Lett 118:212501

    Article  PubMed  Google Scholar 

  14. Minkov N, Pálffy A (2019) Theoretical predictions for the magnetic dipole moment of 229mTh. Phys Rev Lett 122:162502

    Article  CAS  PubMed  Google Scholar 

  15. Minkov N, Pálffy A (2021) 229mTh isomer from a nuclear model perspective. Phys Rev C 103:014313

    Article  CAS  Google Scholar 

  16. Shigekawa Y, Yamaguchi A, Suzuki K et al (2021) Estimation of radiative half-life of 229mTh by half-life measurement of other nuclear excited states in 229Th. Phys Rev C 104:024306

    Article  CAS  Google Scholar 

  17. Dessovic P, Mohn P, Jackson RA et al (2014) 229Thorium-doped calcium fluoride for nuclear laser spectroscopy. J Phys Condens Matter 26:105402

    Article  CAS  PubMed  Google Scholar 

  18. Ellis JK, Wen X-D, Martin RL (2014) Investigation of thorium salts as candidate materials for direct observation of the 229mTh nuclear transition. Inorg Chem 53:6769–6774

    Article  CAS  PubMed  Google Scholar 

  19. Jeet J, Schneider C, Sullivan ST et al (2015) Results of a direct search using synchrotron radiation for the low-energy 229Th nuclear isomeric transition. Phys Rev Lett 114:253001

    Article  PubMed  Google Scholar 

  20. Stellmer S, Schreitl M, Schumm T (2015) Radioluminescence and photoluminescence of Th:CaF2 crystals. Sci Rep 5:15580

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  21. Beeks K, Sikorsky T, Rosecker V et al (2023) Growth and characterization of thorium-doped calcium fluoride single crystals. Sci Rep 13:3897

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  22. Stellmer S, Kazakov G, Schreitl M et al (2018) Attempt to optically excite the nuclear isomer in 229Th. Phys Rev A 97:062506

    Article  CAS  Google Scholar 

  23. Masuda T, Yoshimi A, Fujieda A et al (2019) X-ray pumping of the 229Th nuclear clock isomer. Nature 573:238–242

    Article  CAS  PubMed  Google Scholar 

  24. Zimmermann K (2010) Experiments towards optical nuclear spectroscopy with thorium-229. PhD thesis, Univ Hannover, Germany

  25. Verlinde M, Kraemer S, Moens J et al (2019) Alternative approach to populate and study the 229Th nuclear clock isomer. Phys Rev C 100:024315

    Article  CAS  Google Scholar 

  26. Kraemer S, Moens J, Athanasakis-Kaklamanakis M et al (2023) Observation of the radiative decay of the 229Th nuclear clock isomer. Nature 617:706–710

    Article  CAS  PubMed  Google Scholar 

  27. Browne E, Tuli JK (2008) Nuclear data sheets for A = 229. Nucl Data Sheets 109:2657–2724

    Article  CAS  Google Scholar 

  28. Daimon M, Masumura A (2002) High-accuracy measurements of the refractive index and its temperature coefficient of calcium fluoride in a wide wavelength range from 138 to 2326 nm. Appl Opt 41:5275

    Article  CAS  PubMed  Google Scholar 

  29. Shigekawa Y, Wang Y, Yin X et al (2022) Development of a photon measurement apparatus for observing the radiative decay of 229mTh produced from 229Pa. RIKEN Accel Prog Rep 55:124

    Google Scholar 

  30. Pickett DA, Murrell MT, Williams RW (1994) Determination of femtogram quantities of protactinium in geologic samples by thermal ionization mass spectrometry. Anal Chem 66:1044–1049

    Article  CAS  Google Scholar 

  31. Shen C-C, Cheng H, Edwards RL et al (2003) Measurement of attogram quantities of 231Pa in dissolved and particulate fractions of seawater by isotope dilution thermal ionization mass spectroscopy. Anal Chem 75:1075–1079

    Article  CAS  PubMed  Google Scholar 

  32. Griswold JR, Jost CU, Stracener DW et al (2018) Production of 229Th for medical applications: excitation functions of low-energy protons on 232Th targets. Phys Rev C 98:044607

    Article  CAS  Google Scholar 

  33. Watanabe T, Fujimaki M, Fukunishi N et al (2014) Beam energy and longitudinal beam profile measurement system at RIBF. In: Proceedings of the 5th Int Particle Accelerator Conf (IPAC2014) pp 3566–3568

  34. Ziegler JF, Biersack JP, Ziegler MD (2013) SRIM: the stopping and range of ions in matter

  35. Keller C (1966) The chemistry of protactinium. Angew Chem Int Ed Engl 5:23–35

    Article  CAS  Google Scholar 

  36. Radchenko V, Engle JW, Wilson JJ et al (2016) Formation cross-sections and chromatographic separation of protactinium isotopes formed in proton-irradiated thorium metal. Radiochim Acta 104:291–304

    Article  CAS  Google Scholar 

  37. Trubert D, Guzman FM, Naour CL et al (1998) Behaviour of Zr, Hf, Nb, Ta and Pa on macroporous anion exchanger in chloride-fluoride media. Anal Chim Acta 374:149

    Article  CAS  Google Scholar 

  38. Faris JP, Buchanan RF (1964) Anion exchange characteristics of the elements in nitric acid medium. Anal Chem 36:1157–1158

    Article  CAS  Google Scholar 

  39. Faris J (1978) Separation of metal ions by anion exchange in mixtures of hydrochloric acid and hydrofluoric acid. ANL-78-78.

  40. Kmak KN, Shaughnessy DA, Vujic J (2021) Measurement of the 230Th(p, 2n) 229Pa and 230Th(p, 3n) 228Pa reaction cross sections from 14.1 to 16.9 MeV. Phys Rev C 103:034610

    Article  CAS  Google Scholar 

  41. Steyn GF, Motetshwane MA, Szelecsényi F, Brümmer JW (2021) Pairing of thorium with selected primary target materials in tandem configurations: co-production of 225Ac/213Bi and 230U/226Th generators with a 70 MeV H- cyclotron. Appl Radiat Isot 168:109514

    Article  CAS  PubMed  Google Scholar 

  42. Abusaleem K (2014) Nuclear data sheets for A = 228. Nucl Data Sheets 116:163–262

    Article  CAS  Google Scholar 

  43. Koning AJ, Rochman D, Sublet J-Ch et al (2019) TENDL: complete nuclear data library for innovative nuclear science and technology. Nucl Data Sheets 155:1–55

    Article  CAS  Google Scholar 

  44. National Nuclear Data Center, Nuclear structure and decay data on-line library, Nudat 3.0. https://www.nndc.bnl.gov/nudat3/

  45. Shigekawa Y, Haba H (2022) Surface ionization of protactinium toward implanting 229Pa into a CaF2 crystal. RIKEN Accel Prog Rep 55:126

    Google Scholar 

Download references

Acknowledgements

This experiment was performed at RI Beam Factory operated by RIKEN Nishina Center and CNS, University of Tokyo. This work was supported by JSPS KAKENHI Grant Number 19K23445.

Author information

Authors and Affiliations

  1. Nishina Center for Accelerator-Based Science, RIKEN, Wako, Saitama, 351-0198, Japan

    Yudai Shigekawa, Xiaojie Yin, Akihiro Nambu, Yang Wang & Hiromitsu Haba

Authors
  1. Yudai Shigekawa
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Xiaojie Yin
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Akihiro Nambu
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. Yang Wang
    View author publications

    You can also search for this author in PubMed Google Scholar

  5. Hiromitsu Haba
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to Yudai Shigekawa.

Ethics declarations

Conflict of interest

The authors declare that there is no conflict of interest.

Additional information

Publisher’s Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Rights and permissions

Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Shigekawa, Y., Yin, X., Nambu, A. et al. Production and chemical separation of 229Pa toward observation of γ rays of 229mTh. J Radioanal Nucl Chem 333, 1479–1486 (2024). https://doi.org/10.1007/s10967-023-09069-y

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s10967-023-09069-y

Keywords

Search

Navigation