Atomic radiations in nuclear decay Development of a new code to incorporate atomic data into ENSDF T. Kibèdi, B.Q. Lee, A.E. Stuchbery, K.A. Robinson (ANU) F.G. Kondev (ANL) Tibor Kibèdi, Dep. of Nuclear Physics, Australian National University20th NSDD, Kuwait, 27 – 31 January 2013

Tibor Kibèdi, Dep. of Nuclear Physics, Australian National University20th NSDD, Kuwait, 27 – 31 January 2013 Outline  Motivation  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 Background K álmán 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” Comp. Math. Meth. in Medicine, v2012, Article ID , doi: /2012/ NSDD meeting (IAEA)

Tibor Kibèdi, Dep. of Nuclear Physics, Australian National University20th NSDD, Kuwait, 27 – 31 January 2013 Medical applications - Auger electrons 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.” 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.” Antoine Lacassagne ( ) Claudius Regaud ( )

Tibor Kibèdi, Dep. of Nuclear Physics, Australian National University20th NSDD, Kuwait, 27 – 31 January 2013 Medical applications - Auger electrons (Courtesy of Thomas Tunningley, ANU). Targeted tumor therapy 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.” 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.” Antoine Lacassagne ( ) Claudius Regaud ( )

Tibor Kibèdi, Dep. of Nuclear Physics, Australian National University20th NSDD, Kuwait, 27 – 31 January 2013 Medical applications - Auger electrons 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.” 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.” electrons Biological effect: Linear energy transfer LET, keV/  m Kassis, Int. J. of Rad. Biol, 80 (2004) 789 (Courtesy of Thomas Tunningley, ANU). Targeted tumor therapy

Tibor Kibèdi, Dep. of Nuclear Physics, Australian National University20th NSDD, Kuwait, 27 – 31 January 2013 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 Ed. by A.L. Nichols, et al., NDC(NDS)-0596 Auger emitters: 67 Ga, 71 Ge, 77 Br, 99m Tc, 103 Pd, 111 In, 123 I, 125 I, 140 Nd, 178 Ta, 193 Pt, 195m Pt, 197 Hg 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.” 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). Targeted tumor therapy

Tibor Kibèdi, Dep. of Nuclear Physics, Australian National University20th NSDD, Kuwait, 27 – 31 January 2013 Atomic radiations - Basic concept 1S 2S 2P 3S 3P 3D K L1L1 L2L2 L3L3 M1M1 M2M2 M3M3 M4M4 M5M5 Initial vacancy X-ray emission X-ray photon K  2 X-ray 1 secondary vacancy

Tibor Kibèdi, Dep. of Nuclear Physics, Australian National University20th NSDD, Kuwait, 27 – 31 January 2013 Atomic radiations - Basic concept K L1L1 L2L2 L3L3 M1M1 M2M2 M3M3 M4M4 M5M5 Auger-electron K L2 L3 Auger-electron 2 new secondary vacancies 1S 2S 2P 3S 3P 3D K L1L1 L2L2 L3L3 M1M1 M2M2 M3M3 M4M4 M5M5 Initial vacancy X-ray emission X-ray photon Initial vacancy K  2 X-ray 1 secondary vacancy

Tibor Kibèdi, Dep. of Nuclear Physics, Australian National University20th NSDD, Kuwait, 27 – 31 January 2013 Atomic radiations - Basic concept K L1L1 L2L2 L3L3 M1M1 M2M2 M3M3 M4M4 M5M5 Coster-Kronig electron CK- electron L1 L2 M1 Coster-Kronig transition 2 new secondary vacancies 1S 2S 2P 3S 3P 3D K L1L1 L2L2 L3L3 M1M1 M2M2 M3M3 M4M4 M5M5 Initial vacancy X-ray emission X-ray photon Initial vacancy K  2 X-ray 1 secondary vacancy

Tibor Kibèdi, Dep. of Nuclear Physics, Australian National University20th NSDD, Kuwait, 27 – 31 January 2013 Atomic relaxation and vacancy transfer Vacancy cascade in Xe  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 ~ seconds  Many vacancy cascades following a single ionisation event! Initial vacancy M.O. Krause, J. Phys. Colloques, 32 (1971) C4-67

Tibor Kibèdi, Dep. of Nuclear Physics, Australian National University20th NSDD, Kuwait, 27 – 31 January 2013 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  -decay or electron capture Vacancy cascade in Xe M.O. Krause, J. Phys. Colloques, 32 (1971) C4-67

Tibor Kibèdi, Dep. of Nuclear Physics, Australian National University20th NSDD, Kuwait, 27 – 31 January 2013 Motivation  X-ray and Auger electron spectrum is an integral part of the radiations emitted in nuclear decay  Atomic radiations are important for applications of radioisotopes (medical physics, nuclear astrophysics, nuclear engineering)  ENSDF: atomic radiations are not included

Tibor Kibèdi, Dep. of Nuclear Physics, Australian National University20th NSDD, Kuwait, 27 – 31 January 2013 Atomic transition energies and rates Basic formulas For a single initial vacancy on the K-shell following nuclear decay Number of primary vacancies Internal conversion Electron capture X-ray emission Energy Intensity for L1 shell Auger-electron in an ion

Tibor Kibèdi, Dep. of Nuclear Physics, Australian National University20th NSDD, Kuwait, 27 – 31 January 2013 Existing calculations Physical approach RADARDDEPEckerman & Endo (2007) Howell (1992) Stepanek (2000) Pomplun (2012) Nuclear decay data ENSDFDDEPENSDF ICRP38 Conversion coefficients HsIccRpIcc/BrIccRpIcc, 1978 Band RpIcc2000 StepanekHsIcc, 1971 Dragoun, 1976 Band Electron Capture Ratios 1971 Gove & Martin 1995 Schönfeld1977 Bambynek1971 Gove & Martin, 1970Martin 1971 Gove & Martin, 1970Martin 1971 Gove & Martin Atomic transition rates 1972 Bambynek, RADLST 1974 Scofield, 1995 Schönfeld & Janßen, 2006 Be et al., EMISSION 1991 Perkins, EDISTR Chen, 1972/1975 McGuire, 1983 Kassis, 1974 Scofield, 1974 Manson & Kenedy 1991 Perkins1979 Chen, 1972/1975 McGuire, 1970 Storm & Israel, 1979 Krause Atomic transition energies 1970 Bearden & Burr, Neutral atom 1977 Larkins, Semi-empirical 1991 Perkins, Neutral atom Z/Z+1 (Auger), Neutral atom (X- ray) Dirack-Fock calculation 1991 Desclaux, Dirack-Fock calculation Vacancy propagation Deterministic (+++) Monte Carlo with charge neutralization Monte Carlo

Tibor Kibèdi, Dep. of Nuclear Physics, Australian National University20th NSDD, Kuwait, 27 – 31 January 2013 Existing calculations Auger electron yield per nuclear decay RADARDDEPEckerman & Endo (2007) Howell (1992) Stepanek (2000) Pomplun (2012) 99m Tc (6.007 h) In (2.805 d) I (13.22 h) I (59.4 d) Tl (3.04 d) Vacancy propagation Deterministic (+++) Monte Carlo with charge neutralization Monte Carlo

Tibor Kibèdi, Dep. of Nuclear Physics, Australian National University20th NSDD, Kuwait, 27 – 31 January 2013 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 University20th NSDD, Kuwait, 27 – 31 January 2013 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 coefficients (ICC): 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: 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 University20th NSDD, Kuwait, 27 – 31 January 2013 BrIccEmis  Reads the ENSDF file, evaluates absolute decay intensities of EC, GAMMA, CE and PAIR transitions  Simulates a large number events: 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! ( 55 Fe: 15 k, 201 Tl: 1300k)  Emitted atomic radiations stored on disk (~Gb files)  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 University20th NSDD, Kuwait, 27 – 31 January In EC – vacancy propagation

Tibor Kibèdi, Dep. of Nuclear Physics, Australian National University20th NSDD, Kuwait, 27 – 31 January m Tc atomic radiations below L-shell BE

Tibor Kibèdi, Dep. of Nuclear Physics, Australian National University20th NSDD, Kuwait, 27 – 31 January m Tc atomic radiations – X-rays DDEPBrIccEmis K1K E E-2 K2K E E-2 KK E E-2 L[2.134:3.002] 4.82E E-3 M E-4 N E-1

Tibor Kibèdi, Dep. of Nuclear Physics, Australian National University20th NSDD, Kuwait, 27 – 31 January 2013 BrIccEmis:  10 M simulated decay events  455 type of Auger transitions  1981Ge05: measured Auger electrons in eV only 99m Tc Auger electrons 2012Le09 Lee et al., Comp. Math. Meth. in Medicine, v2012, Art. ID B.Q. Lee, Honours Thesis, ANU 2012 Low energy Auger electrons

Tibor Kibèdi, Dep. of Nuclear Physics, Australian National University20th NSDD, Kuwait, 27 – 31 January m Tc atomic radiations – Auger electrons DDEPBrIccEmis KLL[14.86:15.58] 1.49E E-2 KLX[17.43:18.33] 2.79E E-3 KXY[19.93:21.00] 2.8E E-4 K-total 2.15E E-2 CK LLM2.08E CK LLX E-3 LMM E-2 LMX E-2 LXY E-4 L-total[1.6:2.9] 1.089E E-1

Tibor Kibèdi, Dep. of Nuclear Physics, Australian National University20th NSDD, Kuwait, 27 – 31 January m Tc atomic radiations – Auger electrons DDEPBrIccEmis CK MMX E-1 MXY E+0 Super CK NNN E-1 CK NNX E-1 Total yield Auger electron per nuclear decay ~95% below 500 eV ~95% below 500 eV

Tibor Kibèdi, Dep. of Nuclear Physics, Australian National University20th NSDD, Kuwait, 27 – 31 January m Xe IT – charge state at the end of atomic relaxation  Only a handful of measurements exist for ionization by nuclear decay  131m Xe: F. Pleasonton, A.H. Snell, Proc. Royal Soc. (London) 241 (1957) 141  37 Ar: 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 ~ charge

Tibor Kibèdi, Dep. of Nuclear Physics, Australian National University20th NSDD, Kuwait, 27 – 31 January In – 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 University20th NSDD, Kuwait, 27 – 31 January In – 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 KL 2 L 3 ( 1 D 2 ) energy (eV): Multiplet splitting could not be reproduced in JJ coupling scheme Similar discrepancies have been seen in other elements (Z=47, Kawakami, Phys. Lett A121 (1987) 414) (14)Experiment Kovalik (1999) Semi-empirical Larkins (1979La19) 19381RAINE (2002Ba85)  E≈60 eV!

Tibor Kibèdi, Dep. of Nuclear Physics, Australian National University20th NSDD, Kuwait, 27 – 31 January 2013 Breit and other QED contributions (2002Ga47) Z=49 (In) ~60 eV Alternative solution: Semi empirical corrections, like Larkins (1977La19) or Carlson (1977Ca31) used Alternative solution: Semi empirical corrections, like Larkins (1977La19) or Carlson (1977Ca31) used Gaston et al. Phys. Rev A66 (2002)

Tibor Kibèdi, Dep. of Nuclear Physics, Australian National University20th NSDD, Kuwait, 27 – 31 January 2013 Summary – Program developments  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: 55 Fe 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 55 Fe EC)

Tibor Kibèdi, Dep. of Nuclear Physics, Australian National University20th NSDD, Kuwait, 27 – 31 January 2013 Inclusion of atomic relaxation data into ENSDF CommentX-raysAuger electrons Notation: from IUPAC International Union of Pure and Applied Chemistry Based on initial and final atomic levels involved K-L 3 K-L 1 -L 2 Group sub-shells to reduce number of transitions Summed decay rates Use the mean transition energy for the group L (for L 1 -M 2, … L 3 -O 4 ) But not for K K  1 for K-L 3 K  2 for K-L 2 K  for K-M 3 &K-M 2 KLL (for K-L 1 -L 1, … K-L 3 -L 3 ) KLX (X=M 1 ….,N 1 ….) KXY (X&Y=M 1 ….,N 1 ….)

Tibor Kibèdi, Dep. of Nuclear Physics, Australian National University20th NSDD, Kuwait, 27 – 31 January 2013 Inclusion of atomic relaxation data into ENSDF ENSDF coding: TRANSITION=ENERGY [INTENSITY] 99TC R XKA1=23.25 [0.451]$ XKA2=23.06 [0.239]$ XKB=26.26 [0.142]$ 99TC1 R XL=3.23 [6.90e-2]$ XM=0.424 [0.254]$XN= [1.03]$ 99TC2 R AKLL=19.23 [0.107]$ AKLX=22.46 [4.39E-2]$ AKXY=25.64 [4.29E-3]$ 99TC3 R ALLM=0.032 [4.82E-2]$ ALLX=0.234 [0.132]$ ALMM=2.58 [0.816]$ 99TC4 R ALMX=3.06 [0.188]$ ALXY=3.54 [1.13E-2]$ AMMX=0.098 [0.859]$ 99TC5 R AMXY=0.308 [2.12]$ ANNN=0.020 [0.538]$ ANNX=0.017 [0.681]$ 99TC6 R ANXY=0.054 [0.206] 99TC L 0 9/2+ Before daughter GS level record  Intensity need to be normalised to GAMMA-rays; same normalisation is valid for both  Number of entries on the “R” (RELAXATION) records can automatically generated according to Z  Detailed spectra (list or figure) of the X-rays and Auger electrons can be generated and distributed for the user X-rays Auger electrons