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Calculation of atomic radiations in nuclear decay – BrIccEmis and beyond

Calculation of atomic radiations in nuclear decay – BrIccEmis and beyond. T. Kib è di , B.Q. Lee, A.E. Stuchbery , K.A. Robinson . Tibor Kibèdi, Dep. of Nuclear Physics, Australian National University. DDEP Workshop, Paris, 8-10 October 2012. Outline. Talk is largely based on

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Calculation of atomic radiations in nuclear decay – BrIccEmis and beyond

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  1. Calculation of atomic radiations in nuclear decay – BrIccEmis and beyond T. Kibèdi, B.Q. Lee, A.E. Stuchbery, K.A. Robinson Tibor Kibèdi, Dep. of Nuclear Physics, Australian National University DDEP Workshop, Paris, 8-10 October 2012

  2. Outline • Talk is largely based on • Kȧlmȧn Robertson (ANU) Honours project (2010) • Boon Quan Lee (ANU) Honours project (2012) • 2012Le09 Lee et al., • “Atomic Radiations in the Decay of Medical Radioisotopes: A Physics Perspective” • Computational and Mathematical Methods in Medicine • Volume 2012, Article ID 651475, doi:10.1155/2012/651475 • 2011 NSDD meeting (IAEA) • Radiative and Non-radiative atomic transitions in nuclear decay • Nuclear and atomic data • Existing programs to evaluate atomic radiations • New model based on Monte Carlo approach • Future directions Tibor Kibèdi, Dep. of Nuclear Physics, Australian National University DDEP Workshop, Paris, 8-10 October 2012

  3. Atomic radiations - Basic concept • Vacancies on the inner-shell can be produced by • electron impact • photo ionization • ion-atom collision • internal conversion • electron capture • secondary processes accompanying • b-decay or electron capture 3D 3P M3 M1 M2 M5 M4 3S 2P L1 L2 L3 2S Initial vacancy 1S K Tibor Kibèdi, Dep. of Nuclear Physics, Australian National University DDEP Workshop, Paris, 8-10 October 2012

  4. Atomic radiations - Basic concept X-ray emission 3D 3P M4 M5 M1 M2 M3 3S 2P L1 L2 L3 2S X-ray photon Initial vacancy 1S K Ka2 X-ray 1 secondary vacancy Tibor Kibèdi, Dep. of Nuclear Physics, Australian National University DDEP Workshop, Paris, 8-10 October 2012

  5. Atomic radiations - Basic concept X-ray emission 3D 3P M5 M5 M1 M1 M2 M3 M4 M4 M3 M2 3S 2P L2 L3 L2 L1 L1 L3 2S X-ray photon Initial vacancy Initial vacancy 1S K K Ka2 X-ray 1 secondary vacancy Tibor Kibèdi, Dep. of Nuclear Physics, Australian National University DDEP Workshop, Paris, 8-10 October 2012

  6. Atomic radiations - Basic concept X-ray emission Auger-electron 3D 3P M1 M5 M4 M3 M2 M2 M3 M4 M5 M1 3S Auger-electron 2P L1 L2 L3 L3 L2 L1 2S X-ray photon Initial vacancy Initial vacancy 1S K K K L2 L3 Auger-electron 2 new secondary vacancies Ka2 X-ray 1 secondary vacancy Tibor Kibèdi, Dep. of Nuclear Physics, Australian National University DDEP Workshop, Paris, 8-10 October 2012

  7. Atomic radiations - Basic concept X-ray emission Coster-Kronig electron 3D 3P CK- electron M5 M4 M3 M2 M3 M2 M1 M4 M5 M1 3S 2P L1 L2 L3 L3 L2 L1 2S Initial vacancy X-ray photon Initial vacancy 1S K K L1 L2 M1 Coster-Kronig transition 2 new secondary vacancies Ka2 X-ray 1 secondary vacancy Tibor Kibèdi, Dep. of Nuclear Physics, Australian National University DDEP Workshop, Paris, 8-10 October 2012

  8. Atomic relaxation and vacancy transfer A vacancy cascade in Xe From M.O. Krause, J. Phys. Colloques, 32 (1971) C4-67 O1,2,3 • Full relaxation of an initial inner shell • vacancy creates vacancy cascade involving X-ray (Radiative) and Auger as well as Coster-Kronig (Non-Radiative) transitions • Many possible cascades for a single • initial vacancy • Typical relaxation time ~10-15 seconds • Many vacancy cascades following a • single ionisation event! A A A A A A A A N4,5 N2,3 KC N1 A A A M4,5 M3 M2 M1 A A L3 L2 L1 X Initial vacancy K Tibor Kibèdi, Dep. of Nuclear Physics, Australian National University DDEP Workshop, Paris, 8-10 October 2012

  9. Transition energies and Rates • For a single initial vacancy on the K-shell following nuclear decay Internal conversion Number of primary vacancies Electron capture X-ray emission Auger-electron in an ion Energy Intensity for L1 shell Tibor Kibèdi, Dep. of Nuclear Physics, Australian National University DDEP Workshop, Paris, 8-10 October 2012

  10. Medical applications - Auger electrons • Biological effect: • Linear energy transfer LET, keV/mm electrons Kassis, Int. J. of Radiation Biology, 80 (2004) 789 Tibor Kibèdi, Dep. of Nuclear Physics, Australian National University DDEP Workshop, Paris, 8-10 October 2012

  11. Medical applications - Auger electrons • 2011 August, INDC International Nuclear Data Committee • Technical Meeting on Intermediate-term Nuclear Data Needs for Medical Applications: Cross Sections and Decay Data • Edited by A.L. Nichols, et al., • NDC(NDS)-0596 Targeted tumor therapy Auger emitters: 67Ga , 71Ge, 77Br,99mTc, 103Pd, 111In, 123I, 125I, 140Nd, 178Ta, 193Pt, 195mPt, 197Hg Regaud and Lacassagne (1927) “The ideal agent for cancer therapy would consist of heavy elements capable of emitting radiations of molecular dimensions, which could be administered to the organism and selectively fixed in the protoplasm of cells one seeks to destroy.” (Courtesy of Thomas Tunningley, ANU). Tibor Kibèdi, Dep. of Nuclear Physics, Australian National University DDEP Workshop, Paris, 8-10 October 2012

  12. Existing calculations • Physical approach Tibor Kibèdi, Dep. of Nuclear Physics, Australian National University DDEP Workshop, Paris, 8-10 October 2012

  13. Existing calculations • Auger electron yield per nuclear decay Tibor Kibèdi, Dep. of Nuclear Physics, Australian National University DDEP Workshop, Paris, 8-10 October 2012

  14. Existing programs • Common problems / limitations • In some cases neutral atom binding energies are used for atoms with vacancies; i.e. for ions • Single initial vacancy is considered. Secondary vacancies are • ignored • Atomic radiations only from primary vacancies on the K and L shell • Limited information on sub-shell rates • Auger electrons below ~1 keV are often omitted Tibor Kibèdi, Dep. of Nuclear Physics, Australian National University DDEP Workshop, Paris, 8-10 October 2012

  15. BrIccEmis – Monte Carlo approach for vacancy creation and propagation • Initial state: neutral isolated atom • Nuclear structure data from ENSDF • Electron capture (EC) rates: Schönfeld (1998Sc28) • Internal conversion (IC) coefficients: BrIcc (2008Ki07) • Auger and X-ray transition rates: EADL (1991 Perkins) • Calculated for single vacancies! • Auger and X-ray transition energies: RAINE (2002Ba85) • Calculated for actual electronic configuration! • Vacancy creation and relaxation from EC and IC are treated independently • Ab initio treatment of the vacancy propagation: • Transition energies and rates evaluated on the spot • Propagation terminated once the vacancy reached the valence shell Tibor Kibèdi, Dep. of Nuclear Physics, Australian National University DDEP Workshop, Paris, 8-10 October 2012

  16. BrIccEmis • Reads the ENSDF file, evaluates absolute decay intensities of EC, GAMMA, CE and PAIR transitions • Simulates a number (100k-10M) radioactive decays followed by atomic relaxation • Electron configurations and binding energies stored in memory (and saved on disk). New configurations only calculated if needed. (55Fe: 15 k, 201Tl: 1300k) • Emitted atomic radiations together with shells involved stored like histories in large files (several Gb) • Separate files for X-rays and Auger electrons • Smaller programs to sort/project energy spectra, produce detailed reports Tibor Kibèdi, Dep. of Nuclear Physics, Australian National University DDEP Workshop, Paris, 8-10 October 2012

  17. 111In EC – vacancy propagation Tibor Kibèdi, Dep. of Nuclear Physics, Australian National University DDEP Workshop, Paris, 8-10 October 2012

  18. 99mTc atomic radiations 2.1726 keV below L-shell BE Tibor Kibèdi, Dep. of Nuclear Physics, Australian National University DDEP Workshop, Paris, 8-10 October 2012

  19. 99mTc atomic radiations – X-rays Tibor Kibèdi, Dep. of Nuclear Physics, Australian National University DDEP Workshop, Paris, 8-10 October 2012

  20. 99mTc atomic radiations – Auger electrons Tibor Kibèdi, Dep. of Nuclear Physics, Australian National University DDEP Workshop, Paris, 8-10 October 2012

  21. 99mTc atomic radiations – Auger electrons Tibor Kibèdi, Dep. of Nuclear Physics, Australian National University DDEP Workshop, Paris, 8-10 October 2012

  22. 99mTc Auger electrons BrIccEmis: spectrum from 10 M simulated decay events No experimental spectrum to compare with Tibor Kibèdi, Dep. of Nuclear Physics, Australian National University DDEP Workshop, Paris, 8-10 October 2012

  23. 111In – experiment vs calculation E.A. Yakushev, et al., Applied Radiation and Isotopes 62 (2005) 451 • ESCA; FWHM = 4 eV • Calculations normalized to the strongest experimental line Tibor Kibèdi, Dep. of Nuclear Physics, Australian National University DDEP Workshop, Paris, 8-10 October 2012

  24. 111In – experiment vs calculation A. Kovalik, et al., J. of Electron Spect. and Rel. Phen. 105 (1999) 219 • ESCA; FWHM = 7 eV • Calculated energies are higher • KL2L3(1D2) energy (eV): • Multiplet splitting could not be reproduced in JJ coupling scheme • Similar discrepancies have been seen in other elements (Z=47, Kawakami, Phys. LettA121 (1987) 414) Tibor Kibèdi, Dep. of Nuclear Physics, Australian National University DDEP Workshop, Paris, 8-10 October 2012

  25. K-shell binding energies for superheavy elements (2012Ki04) 2002Ga47 & 2008Th05: Breitmagnetic electron interaction and the quantum electrodynamical (QED) corrections. Tibor Kibèdi, Dep. of Nuclear Physics, Australian National University DDEP Workshop, Paris, 8-10 October 2012

  26. Breit and other QED contributions (2002Ga47) Alternative solution: Semi empirical corrections, like Larkins (1977La19) or Carlson (1977Ca31) used Z=49 (In) ~60 eV Tibor Kibèdi, Dep. of Nuclear Physics, Australian National University DDEP Workshop, Paris, 8-10 October 2012

  27. 131mXe IT – charge state at the end of atomic relaxation • Only a handful of measurements exist for ionization by nuclear decay • 131mXe: F. Pleasonton, A.H. Snell, Proc. Royal Soc. (London) 241 (1957) 141 • 37Ar: A.H. Snell, F. Pleasonton, • Phys. Rev. 100 (1955) 1396 • Good tool to asses the completeness of the vacancy propagation • BrIccEmis: mean value is lower by ~0.7-1.0 charge Tibor Kibèdi, Dep. of Nuclear Physics, Australian National University DDEP Workshop, Paris, 8-10 October 2012

  28. Summary RelaxData/BrIccRelax • BrIccEmis: calculation intensive approach (hours to days) • RelaxData (under development): • Nuclear decay event (EC or CE) produces a SINGLE INITIAL vacancy • Considering a single atomic vacancy the relaxation process independent what produced the vacancy • Compile a database of atomic radiation spectra for • produced by a single initial vacancy on an atomic shell • Carry out calculations of all elements and shells • Example: 55Fe EC, 7 shells for Z=25 and 26, calculated in couple of hours (1 M each shell) • Replace EADL fixed rates and binding energies from RAINE with GRASP2k/RATIP calculations • BrIccRelax (under development): Evaluate primary vacancy distribution and construct atomic spectra from the data base (20 seconds for 55Fe EC) Tibor Kibèdi, Dep. of Nuclear Physics, Australian National University DDEP Workshop, Paris, 8-10 October 2012

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