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JOURNAL OF RADIATION PROTECTION, VOL.34 NO.2 JUNE 2009 69
Table 1. Four Nonlinear Shaping Functions and Twelve Coefficients Used to Fit Peak Spectrum.
shaping function
Gauss main function
background function
Ae
Gauss tail function
(X-P)
2 2
A + Bx + Cx2
A (0.5 +
step function
-
2
1
atan(
Ae
-
P-x
))
b
(X-P)2
2 2
coded form
coded coefficient
GA1 *
exp(-((DX - GP1)/GS1)^2 /2)
GA1,GP1,GS1
BA1 + BB1 * DX +
BC1 * DX^2
BC1,BB1,BA1
SA1 * (0.5 + (1/pi) *
atan((SP1-DX)/SB1))
SA1,SP1,SB1
TA1 *
exp(-((DX - TP1)/TS1)^2 /2)
TA1,TP1,TS1
Table 2. Libraries Used in This Computer Programming.
Library list used in this work
Jedi Code Library v3.1
SDL Scientific Component Suite v7.0
Jedi Visual Component v3.1
TMS Component Pack v3.5
ESB Professional Computation Suite v4.1
SparkSoft Expression Parser v3.4
70 JOURNAL OF RADIATION PROTECTION, VOL.34 NO.2 JUNE 2009
Fig. 1. Main screen of full energy peak analysis program.
Fig. 2. A starting screen of main procedures for optimizing functions.
JOURNAL OF RADIATION PROTECTION, VOL.34 NO.2 JUNE 2009 71
Fig. 3. Screen for determining appropriate initial coefficients values to peak spectrum.
∆X:∆Y:
:Y
∆X
∆Y
Y
72 JOURNAL OF RADIATION PROTECTION, VOL.34 NO.2 JUNE 2009
Fig. 4. Screen for calculated chi square value to optimized shaping functions.
µCi
µs
JOURNAL OF RADIATION PROTECTION, VOL.34 NO.2 JUNE 2009 73
Fig. 5. Fitted curves for 137Cs 661keV peak spectrum.
Table 3. Calculated Coefficients of Nonlinear Shaping Functions for
137
Cs 661keV Gamma Ray Peak Spectrum ( 2R=2.46).
74 JOURNAL OF RADIATION PROTECTION, VOL.34 NO.2 JUNE 2009
coefficient
coefficient value
standard deviation
GA1
472988.
1.46200
GP1
2126.
1.615E-4
GS1
1.928
0.188
TA1
9765.3
173.23
TP1
2122.
2.285E-4
TS1
1.72
0.211
BA1
10.17
4.686
BB1
-1.287E-4
0.004
BC1
-3.080E-6
1.037E-6
SA1
376.
5.19
SP1
2130
0.005
SB1
1.46
1.14E-6
1. Basu SK and Patro AP. SPAN-a Fortran program for
routine and detailed analysis of Gamma spectra using a
small computer. Nucl. Instr. and Meth. 1975;126:115-123.
2. Robinson DC. A computer programme for the
determination of accurate gamma ray line intensities from
germanium spectra. Nucl. Instr. and Meth. 1970;78:120124.
3. Phillips GW and Marlow KW. Automatic analysis of
gamma-ray spectra from germanium detectors. Nucl. Inst.
and Meth. 1976;137:525-536.
4. Helmer RG and Lee MA. Analytical functions for fitting
peaks from Ge semiconductor detectors. Nucl. Instr. and
Meth. 1980;178:499-512.
5. Routti JT and Prussin SG. Photopeak method for the
computer analysis of gamma-ray spectra from
semiconductor detectors. Nucl. Inst. and Meth.
1969;72:125-142.
A Development of GUI Full-Energy Absorption Peak Analysis Program for
Educational Purpose
Jong-Wan Sohn*, Myung-Suk Shin , Hye-Jung Lee , Kyung-Su Jung , Min-Su Jeong and Sang-Nyeon Kim
*
Anyang H. S., Nangok M. S., Kyenam M. S, Konghang H. S., Uijeongbu H. S., Korea National University of Education, Dept. of Physics Education
Abstract - To obtain precise information about characteristics of gamma ray detector system responses, we developed new GUI
computer program to analize full-energy absorption peak using our developed Delphi computer code for educational purpose. By use of
the well known 4 nonlinear peak shaping functions, peaks were fitted with least square fit method in this code. In this paper, we
described the methods to search for 12 coefficients in above 4 nonlinear peak shaping functions by use of our developed code in details.
The computer code was tested for 1 µCi 137Cs 661 keV gamma ray peak spectrum detected by 25 % relative efficiency HPGe detector
with 5.35 cm (D) 5.5 cm (L) size.
Keywords : Delphi Code, Peak Shaping Function, Nonlinear Function Fitting
JOURNAL OF RADIATION PROTECTION, VOL.34 NO.2 JUNE 2009 75