Atomic radiations in nuclear decayDevelopment 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 University 20th NSDD, Kuwait, 27 – 31 January 2013
Tibor Kibèdi, Dep. of Nuclear Physics, Australian National University 20th 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
BackgroundKálmán 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 651475, doi:10.1155/2012/651475
2011 NSDD meeting (IAEA)
Tibor Kibèdi, Dep. of Nuclear Physics, Australian National University 20th 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.”
Antoine Lacassagne (1884-1971)
Claudius Regaud (1870-1940)
Tibor Kibèdi, Dep. of Nuclear Physics, Australian National University 20th 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.”
Antoine Lacassagne (1884-1971)
Claudius Regaud (1870-1940)
Tibor Kibèdi, Dep. of Nuclear Physics, Australian National University 20th 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.”
electrons
Biological effect: Linear energy transfer LET,
keV/mm
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 University 20th 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 DataEd. by A.L. Nichols, et al., NDC(NDS)-0596
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).
Targeted tumor therapy
Tibor Kibèdi, Dep. of Nuclear Physics, Australian National University 20th NSDD, Kuwait, 27 – 31 January 2013
Atomic radiations - Basic concept
1S
2S
2P
3S
3P
3D
K
L1
L2
L3
M1
M2
M3
M4
M5
Initial vacancy
X-ray emission
X-ray
photon
Ka2 X-ray1 secondary
vacancy
22 LKX EEEK
Tibor Kibèdi, Dep. of Nuclear Physics, Australian National University 20th NSDD, Kuwait, 27 – 31 January 2013
Atomic radiations - Basic concept
K
L1
L2
L3
M1
M2
M3
M4
M5
Auger-electron
Auger-
electron
23232
LLLKLLK EEEE
K L2 L3 Auger-electron2 new secondary
vacancies
1S
2S
2P
3S
3P
3D
K
L1
L2
L3
M1
M2
M3
M4
M5
Initial vacancy
X-ray emission
X-ray
photon
Initial vacancy
Ka2 X-ray1 secondary vacancy
22 LKX EEEK
Tibor Kibèdi, Dep. of Nuclear Physics, Australian National University 20th NSDD, Kuwait, 27 – 31 January 2013
Atomic radiations - Basic concept
K
L1
L2
L3
M1
M2
M3
M4
M5
Coster-Kronig electron
CK- electr
on
2121121
LMLLMLL EEEE
L1 L2 M1 Coster-Kronig transition
2 new secondary vacancies
1S
2S
2P
3S
3P
3D
K
L1
L2
L3
M1
M2
M3
M4
M5
Initial vacancy
X-ray emission
X-ray
photon
Initial vacancy
22 LKX EEEK
Ka2 X-ray1 secondary vacancy
Tibor Kibèdi, Dep. of Nuclear Physics, Australian National University 20th 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 vacancyTypical relaxation time ~10-15
secondsMany vacancy cascades
following a single ionisation event!
K
O1,2,3
L1
L2
L3
M1
M2
M3
M4,5
N1
N2,3
N4,5
X
AA
AAA
KC
AAAAAA
AA
Initial vacancy
M.O. Krause, J. Phys. Colloques, 32 (1971) C4-67
Tibor Kibèdi, Dep. of Nuclear Physics, Australian National University 20th 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
accompanyingb-decay or electron capture
Vacancy cascade in Xe
K
O1,2,3
L1
L2
L3
M1
M2
M3
M4,5
N1
N2,3
N4,5
X
AA
AAA
KC
AAAAAA
AA
M.O. Krause, J. Phys. Colloques, 32 (1971) C4-67
Tibor Kibèdi, Dep. of Nuclear Physics, Australian National University 20th 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 University 20th 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 T
KK Pn
1Internal conversion
Electron captureKK PPn
X-ray emission
Energy YKX EEEKY
Intensity KKX nIKY
for L1 shell 111 LLX nIYL
Auger-electron
XYXKKXY EEEE
KKKXY anI 1 KK a
)( 312111 LLLLLKXYL ffanI
1312111 LLLLLL ffa
in an ion
Tibor Kibèdi, Dep. of Nuclear Physics, Australian National University 20th NSDD, Kuwait, 27 – 31 January 2013
Existing calculationsPhysical approach
RADAR DDEP Eckerman & Endo(2007)
Howell(1992)
Stepanek(2000)
Pomplun(2012)
Nuclear decay data
ENSDF DDEP ENSDF ENSDF ENSDF ICRP38
Conversion coefficients
HsIcc RpIcc/BrIcc RpIcc,1978 Band
RpIcc 2000 Stepanek HsIcc,1971 Dragoun,
1976 Band
Electron Capture Ratios
1971 Gove & Martin
1995 Schönfeld 1977 Bambynek 1971 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,EDISTR04
1979 Chen,1972/1975 McGuire,
1983 Kassis, 1974 Scofield, 1974
Manson & Kenedy
1991 Perkins 1979 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 Deterministic Deterministic(+++)
Monte Carlowith charge
neutralization
Monte Carlo Monte Carlo
Tibor Kibèdi, Dep. of Nuclear Physics, Australian National University 20th NSDD, Kuwait, 27 – 31 January 2013
Existing calculationsAuger electron yield per nuclear
decayRADAR DDEP Eckerman &
Endo(2007)
Howell(1992)
Stepanek(2000)
Pomplun(2012)
99mTc (6.007 h) 0.122 0.13 4.363 4.0 2.5
111In (2.805 d) 1.136 1.16 7.215 14.7 6.05
123I (13.22 h) 1.064 1.08 13.71 14.9 6.4
125I (59.4 d) 1.77 1.78 23.0 24.9 15.3 12.2
201Tl (3.04 d) 0.773 0.614 20.9 36.9
Vacancy propagation
Deterministic Deterministic Deterministic(+++)
Monte Carlowith charge
neutralization
Monte Carlo Monte Carlo
Tibor Kibèdi, Dep. of Nuclear Physics, Australian National University 20th 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 University 20th 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 University 20th 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!
(55Fe: 15 k, 201Tl: 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 University 20th NSDD, Kuwait, 27 – 31 January 2013
111In EC – vacancy propagation
Tibor Kibèdi, Dep. of Nuclear Physics, Australian National University 20th NSDD, Kuwait, 27 – 31 January 2013
99mTc atomic radiations
below L-shell BE
Tibor Kibèdi, Dep. of Nuclear Physics, Australian National University 20th NSDD, Kuwait, 27 – 31 January 2013
99mTc atomic radiations – X-rays
DDEP BrIccEmis
Ka1 18.36724.21E-2
18.4214.05E-2
Ka2 18.2512.22E-2
18.3022.13E-2
Kb 20.6771.30E-2
20.7291.18E-2
L [2.134:3.002]4.82E-3
2.4664.72E-3
M 0.2637.83E-4
N 0.0478.73E-1
Tibor Kibèdi, Dep. of Nuclear Physics, Australian National University 20th NSDD, Kuwait, 27 – 31 January 2013
BrIccEmis: 10 M simulated decay events 455 type of Auger transitions 1981Ge05: measured Auger electrons
in 1500-2300 eV only
99mTc Auger electrons
2012Le09 Lee et al., Comp. Math. Meth. in Medicine, v2012, Art. ID 651475 B.Q. Lee, Honours Thesis, ANU 2012
Low energy Auger electrons
Tibor Kibèdi, Dep. of Nuclear Physics, Australian National University 20th NSDD, Kuwait, 27 – 31 January 2013
99mTc atomic radiations – Auger electrons
DDEP BrIccEmis
KLL [14.86:15.58]1.49E-2
15.371.48E-2
KLX [17.43:18.33]2.79E-3
17.855.58E-3
KXY [19.93:21.00]2.8E-4
20.275.07E-4
K-total2.15E-2
16.152.08E-2
CK LLM 2.08E-20.054
CK LLX 0.1449.48E-3
LMM 2.0169.02E-2
LMX 2.3281.41E-2
LXY 2.6546.07E-4
L-total [1.6:2.9]1.089E-1
1.7651.24E-1
Tibor Kibèdi, Dep. of Nuclear Physics, Australian National University 20th NSDD, Kuwait, 27 – 31 January 2013
99mTc atomic radiations – Auger electrons
DDEP BrIccEmis
CK MMX 0.1047.10E-1
MXY 0.1701.10E+0
Super CK NNN 0.0145.36E-1
CK NNX 0.0128.45E-1
Total yield Auger electron per nuclear decay 0.13 3.37
~95% below 500
eV
Tibor Kibèdi, Dep. of Nuclear Physics, Australian National University 20th NSDD, Kuwait, 27 – 31 January 2013
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 20th NSDD, Kuwait, 27 – 31 January 2013
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 20th NSDD, Kuwait, 27 – 31 January 2013
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. Lett A121 (1987) 414)
19319.2(14) Experiment Kovalik (1999)
19308.1 Semi-empirical Larkins (1979La19)
19381 RAINE (2002Ba85)
DE≈60 eV!
Tibor Kibèdi, Dep. of Nuclear Physics, Australian National University 20th 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
Gaston et al. Phys. Rev A66 (2002) 062505
Tibor Kibèdi, Dep. of Nuclear Physics, Australian National University 20th 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: 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 20th NSDD, Kuwait, 27 – 31 January 2013
Inclusion of atomic relaxation data into ENSDF
Comment X-rays Auger electrons
Notation: from IUPAC • International Union of Pure and Applied
Chemistry• Based on initial and final atomic levels involved
K-L3 K-L1-L2
Group sub-shells to reduce number of transitions
• Summed decay rates• Use the mean transition energy for the group
L (for L1-M2, … L3-O4)
But not for KKa1 for K-L3
Ka2 for K-L2
K b for K-M3&K-M2
KLL(for K-L1-L1, … K-L3-L3)
KLX (X=M1….,N1….)
KXY (X&Y=M1….,N1….)
Tibor Kibèdi, Dep. of Nuclear Physics, Australian National University 20th 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]$XN=0.0477 [1.03]$ 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