Validation of inner shell ionization cross sections for

electron transport

Sung Hun, Kim

Nuclear Engineering, Hanyang University, Seoul, Republic of Korea

Chan Hyeong, Kim

-Chairman of subdivision, International Commission on Radiological Protection(ICRP), 2013-present-Assistant/Associate/Full Professor, Hanyang University, Seoul, Korea, 2003-present- Visiting Scholar, University of Florida, Gainesville, Florida, 2009-2010- Assistant Professor, Rensselaer Polytechnic Institute (RPI), Troy, New York, 2001-2003- Assistant Director, TAMU Nuclear Science Center, College Station, Texas, 1998-2001- Researcher & Senior Researcher, Korea Institute of Nuclear Safety, Seoul, Korea, 1988-1995

Related, optimization of parameters used in cross section calculations

Best Student Paper Award, Monte Carlo 2010Visitor with CERN/PH/SFT, 2009

Precision modeling of

electron impact ionisation

DosimetryMicrodosimetryRadiation damageScintillationDetectors

Energy deposition

Elemental analysisXRF and AES

Isolated Atom ApproximationIndependent Particle Approximation

Experimental applications

Quantitative estimate of the accuracy of transport input

parameters

Monte Carlo simulation

R&D

Foundation of electromagnetic transport

Uncertainty quantification

ValidationEstablish the state-of-the-art in

modeling electron impact ionisation Provide objective guidance to experimental users of Geant4

Validation of inner shell ionization cross sections for

electron transport

Theoretical Models

• EEDL in Geant4 (1991)

• BEB• DM• Bote et al. (up to 1 GeV)

Specialized for low energies

Explore models not yet available in Geant4

Experimental data

0

500

1000

1500

2000

2500

3000

3500

4000

2619

633

128 69

3449

Number of dataNumber of data

Software designUML class diagram

Policy-based class design (A. Alexandrescu, Modern C++ design, Addison-Wesley, 2001)

Atomic parameters domain: functional, design iteration foreseenData management domain: functional, improved design exists, migration foreseen

Produced with

Results

Results

Results

Results

Results

Results

Statistical data analysis

• Goodness-of-fit tests to determine the compatibility of each model with experimental data– c2 test

• Categorical analysis to determine if the differences in compatibility with experiment of the various models are statistically significant– Fisher’s exact test– Barnard’s test– Pearson’s c2 test (if applicable)– c2 test with Yates’ continuity correction (if necessary)

EfficiencyFraction of test cases that “pass” the c2 test

BEB and DM models are intended for low energies (<10 keV); here they are stretched beyond their nominal range to investigate their actual capabilities

EEDL and Bote models appear the most efficient at reproducing measurements

Test significance: a=0.01p-value ≥ a Passp-value < a Fail

Preliminary results of categorical analysis

138 169

136 105

Fisher 0.0098Pearson c2 0.0076Barnard 0.0079

23 33

20 11

6 8

7 4

Fisher 0.0453Pearson c2 0.0362Barnard 0.0383

Fisher 0.4283Barnard 0.3519

K shell

L shell

M shell

0.01 significance

0.05 significance

Small data sample

Study of systematics in progress

EEDL Bote

PassFail

Test p-value

Conclusion & Impact

Total Ionization Cross section

Inner-shell Ionization Cross

sections

New Electron Data Library

Q&A

• Thank you.