USE OF KCL REFERENCE SAMPLES TO CALIBRATE THE EFFICIENCY
OF A GROSS ALPHA/BETA COUNTING SYSTEM MPC 2000
MARIAN ROMEO CǍLIN1, ALEXANDRU ERMINIU DRUKER2
1
Horia Hulubei National Institute of Physics and Nuclear Engineering
IFIN-HH, Bucharest-Magurele, POB MG-6, Romania, e-mail: [email protected]
2
National Institute of Metrology, Bucharest
Received November 26, 2009
Several methods were used for the efficiency calibration of a counting system
ORTEC PROTEAN MPC-2000-DP by using KCl reference samples (reference sources
of naturally radioactive potassium chloride), along with 241Am and 90(Sr-Y) radioactive
sources. The operations were part of gross alpha and beta counts in various samples at
the IFIN-HH SALMROM Laboratory specializing in the spectroscopic survey of the
environment and radioactive materials.
Key words: gross alpha and beta counter, calibration, gross alpha/beta counts.
1. INTRODUCTION
The equipment we used was a low-background gross alpha/beta counter
ORTEC PROTEAN, MPC-2000-DP, with the following setup: a ZnS scintillation
detector - dual phosphorus detector (zinc sulfide and plastic), model MPC-2000DP, high voltage supply (for the detector); signal processing modules;
preamplifier; amplifier; counter; display module; operation and display control
board equipped with LCD display; mechanical sample feeder; PC interface (RS
485/RS 232), special device to download data acquired and processed by the MPC
2000 (PIC Communicator - Protean Instrument Corporation). For calibration
sources, we used sets of 241Am alpha punctual sources and 90(Sr-Y) beta punctual
sources, as well as alpha and beta calibration sources (reference samples) made at
two chemical labs.
2. SCOPE AND METHOD
We used a fixed geometry in metallic sample trays, in the MPC 2000 lead
shield, directly facing the detector probe; two counting geometries were used:
Rom. Journ. Phys., Vol. 56, Nos. 3–4, P. 373–387, Bucharest, 2011
374
Marian Romeo Cǎlin, Alexandru Druker
2
• Counting geometry I – counting routine: Gross α - β manual count; tray
geometry 8 mm below the probe/detector; and
• Counting geometry I – counting routine: ALFA+BETA SUS manual count;
tray geometry 3 mm below the probe/detector.
Reference conditions were as follows: temperature: (20 ± 2)0 C, pressure:
1013.25 hPa, while ambient conditions were: temperature: (22 ± 0.1)0 C,
pressure: 1002 ± 0.2 hPa and humidity: 35%.
The settings of the MPC 2000 measuring system were done in conformity
with the following procedures: “The measuring of sample activity with the global
alfa/beta MPC 2000 system” and „The efficient calibration of the measuring
system of samples with the global alfa/beta MPC 2000 system.”
For the initial calibration and standardization of MPC 2000 system we used
radioactive sources of: 241Am si 90(Sr-Y) and reference samples of KCl (Potassium
Chloride) prepared in the laboratory in two sets, each containing 7 samples (Set 1 –
CPR si Set 2 – DFVM) – ethalon samples of natural radioactive KCl. The weight
of the KCl samples was between 0.4 g and 1 g as it can be seen in Table 1, bearing
4 decimals. The ethalon samples were meassured with the MPC 2000 system in
6 intervals of 5 minutes, resulting a total measuring time of 30 minutes. The best
set of ethalon samples was choosen having the smallest measuring errors(Set 2 –
DFVM, as it can be observed in Table 6). In addition to this, we performed a
measurement with the empty tray in the same work procedure, visible on line 15 of
Table 1. The data showing the weight of the work samples and their measuring
errors are shown in Table 1.
Table1
The weight of refernce KCI samples
No.
SAMPLE
SAMPLE CODE
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
sample 1 - CPR
sample 2 - CPR
sample 3 - CPR
sample 4 - CPR
sample 5 - CPR
sample 6 - CPR
sample 7 - CPR
sample 1 - DFVM
sample 2 - DFVM
sample 3 - DFVM
sample 4 - DFVM
sample 5 - DFVM
sample 6 - DFVM
sample 7 - DFVM
empty tray
KCl 0.4 A - carrier 1
KCl 0.5 A - carrier 2
KCl 0.6 A - carrier 3
KCl 0.7 A - carrier 4
KCl 0.8 A - carrier 5
KCl 0.9 A - carrier 6
KCl 1.0 A - carrier 7
KCl 0.4 B - carrier 8
KCl 0.5 B - carrier 9
KCl 0.6 B - carrier 10
KCl 0.7 B - carrier 11
KCl 0.8 B - carrier 12
KCl 0.9 B - carrier 13
KCl 1.0 B - carrier 14
empty tray - carrier 15
WEIGHT
(g)
0.4004
0.5003
0.6002
0.7004
0.8003
0.9000
1.0000
0.4028
0.5028
0.6028
0.7028
0.8028
0.9028
1.0028
0.0000
ERROR
±0.0001
±0.0001
±0.0001
±0.0001
±0.0001
±0.0001
±0.0001
±0.0001
±0.0001
±0.0001
±0.0001
±0.0001
±0.0001
±0.0001
±0.0000
3
A gross alpha/beta counting system MPC 2000
1.
375
EXPERIMENTAL RESULTS
The samples were measured, and the characteristic calibration curve of the
detector was drawn (Graphs 1 and 2) with the help of the PICPLAT_KCl01
(PICPLAT_KCl_GRAPH) file from the “calibration” folder of the measuring
system. The graphs were made with the EXCEL software, according to table 2 (x
axis – the power tension of the detector; y axis – registered the events).
Thus we obtained:
Table 2
Counts = f (U)
DP Detector
Plateau Data
VOLTS (V)
705
720
735
750
765
780
795
810
825
840
855
870
885
900
915
930
945
960
975
990
1005
1020
1035
1050
1065
1080
PIC MPC2000BDP
COUNTS
1
8
22
58
138
317
541
947
1548
2222
3009
4053
5140
6341
7753
8996
10252
12432
14127
16620
19581
22276
25093
27722
28698
29495
SLOPE(%/100
volts)
0
0
0
0
0
97.54
83.09
71.57
62.53
55.23
49.22
44.43
40.49
36.7
33.37
31.39
29.47
28.33
27.33
25.88
24.62
22.96
20.56
17.65
13.3
8.32
MPC-2000 BDP Plat
Voltage Range 705 to
1290 volts in 15 volt
increments
Umber 1 Detector Plateau
Data
MPC-2000BDP Plat
376
Marian Romeo Cǎlin, Alexandru Druker
4
Table 2 (continued)
1095
1110
1125
1140
1155
1170
1185
1200
1215
1230
1245
1260
1275
1290
29585
29914
29587
29578
29884
30138
30078
29808
30126
30463
30211
30077
30329
30439
4.16
0.37
0.57
1.55
2.98
1.37
0.34
1.44
1.85
1.29
0.04
0.15
0
0
COUNTS
35000
30000
25000
20000
15000
10000
5000
0
700
800
900
1000
1100
1200
1300
Graph 1 Plateau curve in concordance to the tension.
SLOPE
28
23
18
13
8
3
-2
1000
1050
1100
1150
1200
Graph 2 Plateau curve interest zone beta.
1250
1300
5
A gross alpha/beta counting system MPC 2000
377
The point-like sources of 241Am and 90(Sr-Y) were also measured and then
the file of mesuring data was established: PICDATA_KCL01_FINAL “ULTERIOR
PROCESSING OF MEASUREMENTS DONE FOR STANDARDIATION/
CALIBRATION” (table 8) from the “calibration” folder of the measuring system.
This folder containing the data got by the specialized software PIC Comunicator
carries all the characteristic parameters of the system and it was the source of the
experimental data used in the standardization report and in the report regarding the
validation of the word procedure. The measuring data was studied in conformity
with the folder PICDATA_KCL01_FINAL (PICDATA_KCL01, KCL_BETA –
Weight of the made ethalon sample-1, sample-2, sample-3: The influence of the
sample’s weight – The autoabsorbtion correction and the influence of the operator
who is preparing the refence samples. The experimental data obtained in this way
are in conformity with the technical data and the specifications of the system and
the detection eficiency for the alfa, beta and Spillover factor Xtalk were calculated
with the formulas below and are present in Table 3 and 4.
εβ =
εα =
CPM β − FondCPM β
DPM β
× 100; for the beta radiation;
CPM α − Fond CPM α
× 100; for the alpha radiation;
DPM α
X talk =
CPM β − FondCPM β
CPM α − FondCPM α
× 100;
For the measuring of the samples and the radiation sources the two methods of
work were used:
Measuring geometry I
• the measuring rutine Gross α - β manual count;
• in the tray geometry, at the level of 8 mm under the detector probe;
• conversion to Bq coefficient in conformity to the ISO 7503-1/1998;
• without backscattering;
• does not include the absorption correction in the samples;
• the beta and alpha source with ∅ 22 mm;
• measuring time: 30 minutes;
For this geometry we obtained the detection efficiencies presented in Table 3.
378
Marian Romeo Cǎlin, Alexandru Druker
6
Table 3
Detection efficiencies in measure I geometrics
SURCE/Radionucleid
SI
(imp/s)/Bq=
(imp/min)/(dez/min)=
(CPM)/(DPM)
Beta Surce 90(Sr-Y)
0,89872 ±
0,0138
imp/(β in 2π)
0,44936 ± 0,0069
0,62730 ±
0,0050
imp/(α in 2π)
0,31365 ± 0,0025
εα = 31,365 ±
0,25
0,2559 ± 0,0050
25,59 ± 0,50
(max. beta en. 546+2260keV
medium beta en. 565,5 keV)
Alfa Source 241Am
(alfa en. 5,39...5,49 MeV;
medium alfa en. 5,4774 MeV)
Xtalk
Detection
efficiences
(% )MPC2000
εβ = 44,936 ±
0,69
Measuring geometry II
• the measuring rutine ALFA+BETA SUS manual count;
• in the tray geometry, at the level of 8 mm under the detector probe;
• conversion to Bq coefficient in conformity to the ISO 7503-1/1998;
• without backscattering;
• does not include the absorption correction in the samples;
• the beta and alpha source with ∅ 22 mm;
• measuring time: 30 minutes.
For this geometry we obtained the detection efficiencies presented in Table 4.
Table 4
Detection efficiencies in measure II geometrics
SOURCE/Radionucleid
SI
(imp/s)/Bq =
(imp/min)/(dez/min)=
(CPM)/ (DPM)
Beta Source 90(Sr-Y)
0,89872 ±
0,0138
imp/(β în 2π)
0,4853 ± 0,0074
0,80574 ±
0,0142
imp/(β in 2π)
0.40287±
40,287±0,71
0,7246 ±
0,0058
imp/(α in 2π)
0,3623 ± 0,0029
εα = 36,23 ±
0,29
0,3108 ± 0,006
31,08 ± 0,60
(max.beta en. 546+2260keV
medium beta en. 565,5 keV)
Sources/
KCl reference samples
Alfa Source 241Am
(alfa en. 5,39...5,49 MeV;
medium alfa en. 5,4774 MeV )
Xtalk
Detection
efficiences
(% )MPC2000
εβ = 48,53 ±
0,74
7
A gross alpha/beta counting system MPC 2000
379
As to the influence of the operator preparing the reference samples, we can
state that the reference potassium chloride (KCl) standard sample sets have been
prepared by two different operators (Operator 1 – CPR and Operator 2 – DFVM)
and their influence in the preparation of the standard samples is shown in Table 6
(standardization file PICDATA_KCL01_FINAL/probe 3).
The relative maximum and minimum errors and beta efficiences in BEFF (%)
for every KCl sample have also been calculated, for each of the two operators.
The resulting data (experimental results) is shown in the standardization file:
PICDATA_KCL01_FINAL/KCL_BETA, and the resulting second degree fitting
curve is:
y = 5.4799x2 - 18.064x + 50.044
MAX ERR [%] -4.316
MIN ERR [%]
4.190
y = 5.4799x2 – 18.064x + 50.044
Coefficients fitare: 5.4799
-18.064
50.044
The EXCEL file – Weight of realised Standard/Errors for Potassium
Chloride (Table 7) was used to facilitate de measuring of the reference KCl
standard samples. This file allows the determination of the mass acivity in (Bq/g)
of a standard sample, for different inserted masses of KCl, etc.
Observation: The reference for the data is: “Halbwertszeiten und PhotonenEmissionswahrscheinlichkeiten von häufig verwendeten Radionukliden”-2005 eiwerterte und
korrigierte Auflage von Ulrich Schötzig und Heinrich Schrader Physikalisch-Technische
Bundesanstalt (PTB), Braunschweig [1].
The influence of the sample mass and the autoabsorbtion correction on the
measurements is also set out in the EXCEL standardization file:
PICDATA_KCL01_FINAL/probe 2. The general medium error (% relative),
maximum error (% relative), minimum error (% relative), maximum error for the
neglection of the autoabsorbtion correction – for averages and maximum error for
the neglection of the autoabsorbtion correction for all points have also been
calculated (as shown in Table 6).
380
Marian Romeo Cǎlin, Alexandru Druker
8
The repetability of the measurements/tests is shown/calculated/demonstrated
in the PICDATA_KCL01_FINAL/probe 1 file (on 7 x 2 KCl sample sets), to which
was added an empty tray measurement. The AVERAGE, S[n-1], S[n-1] (%),
S[AVERAGE], S[AVERAGE] (%), and also the efficiency/efficacy - BEFF to beta
radiation
(%),
BEFF-2S(n-1),
BEFF+2S(n-1),
BEFF-2S[AVERAGE],
BEFF+2S[AVERAGE] and AVERAGE (%) and S[POISSON], were measured
and are shown for each measurement/test (Table 8).
The minimum detectable activity (MDA) was determined through repeated
measurements and takes the form: MDA= 3 Sfond/Eff; For KCl standard samples
and for 241Am si 90(Sr-Y) standard samples, the MDA is: MDA/alfa = 0.0747 Bq
and MDA/beta = 0.371 Bq. The resulting MDAs are in concordance with the data
in the technical specifications of the system. As for the time range error, the rootmean square error for a singular measurement for the time range is smaller than
0,0001 % (as shown in Table 8).
4. COMPARING THE RESULTS
The validation of the calibrating in efficiency method was accomplished by
organizing a comparison attended by the SALMROM (DFVM) and LAS (STDR)
laboratories. The unknown radiation standard sources were: 90(Sr-Y) and 241Am,
with the characteristics described in the Standard Certificates. The SALMROM
tests were done in accordance with the working procedures and the SR EN
ISO/CEI 17025: 2005 [2] referential, and the activity values measured by the two
laboratories are comparable, with small departures from the conventionally true
values. The measured data is shown in Table 5.
Table 5
RADIOACTIVE
SOURCE/
Characteristics
1.
2.
Detectable beta
activity, „ALFA +
BETA SUS” routine
90
(Sr-Y) SEB 7-4673
Source/
MPC 2000 System
Routine detectable
alfa activity „ALFA
+ BETA SUS”
241
Am SEA 4-1
Source/ MPC 2000
System
Results
Activity [Bq]
Measurement uncertainty
SALMROM
LAS
SALMROM
LAS
Uncertaint
y[Bq]
7.01x103
6.78 x103
Err (%)= -0.17%
251
1.38x104
1.43 x104
Err (%)=-11.53%
425
ELEME
NT
H
A
B
ATOMIC MASS
0
Table 7
0.672
4.190
-4.316
-1.104
1.339
-3.528
-2.403
-1.410
-1.710
0.323
3.119
0.217
1.029
3.113
REL. ERR
towards
FIT [%]
0.4004 g KCl / Sample==
g KCl /
0.0001 SAMPLE==
ERROR
MASUREM
ENT
MASS
-4.316
-4.316
-4.316
-4.316
-4.316
-4.316
-4.316
MAX ERR
[%]
OPERATOR 2 = DFVM
10 g KCl / Sample==
50 g KCl / Sample==
100 g KCl / sample==
The weight of the made ethalon
ATOMIC MASS PERCENT
0
INTRODUCES VALUE
MASS===>
NR.de ATOMI
KCl
43.690
42.378
41.176
40.080
39.097
38.225
37.460
REL. ERR towards
FIT [%]
OPERATOR 1= CPR
The weight of the made ethalon/Errors for the Potassyum Chloride
43.074
41.654
41.309
41.330
39.182
38.618
38.626
OPERATOR 2 = DFVM
BEFF
CURVE
[%]
FIT gr.2
POTASSYUM CHLORIDE
AVERAGE======== >
43.983
44.154
39.399
39.638
39.621
36.876
36.560
FORMULA====>
SUBSTANCE
MASS
0.400
0.500
0.600
0.700
0.800
0.900
1.000
BEFF [%]
OPERATOR 1= CPR
The influence of the operator whi is preparing the reference samples
Table 6
Yield BETA
40-K
89.33 %
4.190
4.190
4.190
4.190
4.190
4.190
4.190
MIN ERR.
[%]
Table 7 (continued)
QUANTITY K [ g ] AT THE WEIGHT OF ETHALON
K
39.102
39.0983
1
39.102 0.52447
SOURCE
0.47552
Cl
35.453
35.4527
1
35.453
8
5.24472 g
O
0
0
26.2236 g
MOLECULAR MASS =
reference A=>
74.555
52.4472 g
DIFERENCE BETWEEN
THEM=====>
0.00537%
0.21 g
MOLECULAR MASS =
reference B=>
74.551
ACTIVITY K-40 [ Bq ] AT THE WEIGHT OF ETHALON
SOURCE
162.167 Bq
MASS
VALUE ERROR
810.834 Bq
ACTIVITY
K-40
30.92
0.22 Bq/g K-nat
1621.67 Bq
ERROR
READS VALUE
0.71% ACTIVITY===>
6.49315 Bq
0.74%
348.
REFERENCE:
02 DPM
“Halbwertszeiten und Photonen-Emissionswahrscheinlichkeiten von häufig verwendeten Radionukliden”-2005
eiwerterte und korrigierte Auflage
von Ulrich Schötzig und Heinrich Schrader
Physikalisch-Technische Bundesanstalt (PTB), Braunschweig.
0.5003
0.5003
0.6002
0.6002
0.6002
0.6002
0.6002
0.6002
0.7004
0.7004
0.7004
0.7004
0.7004
0.7004
0.0001
0.0001
0.0001
0.0001
0.0001
0.0001
0.0001
0.0001
0.0001
0.0001
0.0001
0.0001
0.0001
0.0001
434.8513
434.8513
521.6825
521.6825
521.6825
521.6825
521.6825
521.6825
608.7744
608.7744
608.7744
608.7744
608.7744
608.7744
0.737%
0.737%
0.734%
0.734%
0.734%
0.734%
0.734%
0.734%
0.731%
0.731%
0.731%
0.731%
0.731%
0.731%
45.434
45.756
38.255
38.907
39.175
40.057
40.095
39.904
40.306
39.156
37.185
40.568
39.977
40.634
1.649
1.654
1.382
1.389
1.393
1.408
1.407
1.405
1.294
1.277
1.249
1.298
1.288
1.298
12.77
13.57
-5.04
-3.43
-2.76
-0.57
-0.48
-0.95
0.05
-2.81
-7.70
0.70
-0.77
0.86
BEFF_ERR
MASS ERR_MASS ACTIVITY ERR_ACT BEFF
Gen Avg ERR
_absolut
[g]
[g]
[DPM]
[%]
[%]
[% relativ]
[%]
0.4004
0.0001
348.0201
0.742%
44.989
1.872
11.67
0.4004
0.0001
348.0201
0.742%
44.701
1.865
10.96
0.4004
0.0001
348.0201
0.742%
41.828
1.816
3.82
0.4004
0.0001
348.0201
0.742%
43.610
1.848
8.25
0.4004
0.0001
348.0201
0.742%
44.587
1.866
10.67
0.4004
0.0001
348.0201
0.742%
44.184
1.856
9.67
0.5003
0.0001
434.8513
0.737%
43.088
1.612
6.95
0.5003
0.0001
434.8513
0.737%
42.398
1.602
5.24
0.5003
0.0001
434.8513
0.737%
44.054
1.627
9.35
0.5003
0.0001
434.8513
0.737%
44.192
1.629
9.69
1.20
39.399
0.7447414
1.89
0.3040394
0.77
39.638
1.3168505
3.32
0.537602
1.36
S[AVERAGE]=[%]==>
AVERAGE ======= >
S[n-1]========>
S[n-1]===[%]===>
S[AVERAGE]=====>
S[AVERAGE]=[%]==>
AVERAGE ======= >
S[n-1]========>
S[n-1]===[%]===>
S[AVERAGE]=====>
S[AVERAGE]=[%]==>
44.154
AVERAGE ======== >
1.2987282
S[n-1]========>
2.94
S[n-1]===[%]===>
0.5302036
S[AVERAGE]=====>
43.983
AVERAGE ======== >
1.1589448
S[n-1]========>
2.63
S[n-1]===[%]===>
0.4731372
S[AVERAGE]=====>
1.08
S[AVERAGE]=[%]==>
1.07
1.15
1.18
1.29
[% relative]
S[POISSON]
Further processing for standardization/calibration after measurement
Table 8
-1.61
-2.21
9.60
9.17
ERR med gen
[% relativ]
ERROR
ACTIVITY
AVERAGE ON
MED=40.287
S[n-1]=2.391073
S[n-1]=[%]=5.94
S[AVERAGE]=0.639041
S[AVERAGE][%]=1.586
S[n-1] = 2.612765
S[n-1] [%]=6.49
S[AVERAGE]=0.285076
S[AVERAGE] [%] =0.71
AVERAGE =40.28
0.8003
0.9000
0.9000
0.9000
0.9000
0.9000
0.9000
1.0000
1.0000
1.0000
1.0000
1.0000
1.0000
0.4028
0.4028
0.4028
0.4028
0.4028
0.4028
0.5028
0.5028
0.5028
0.5028
0.5028
0.5028
0.8003
0.8003
0.8003
0.8003
0.8003
0.0001
0.0001
0.0001
0.0001
0.0001
0.0001
0.0001
0.0001
0.0001
0.0001
0.0001
0.0001
0.0001
0.0001
0.0001
0.0001
0.0001
0.0001
0.0001
0.0001
0.0001
0.0001
0.0001
0.0001
0.0001
0.0001
0.0001
0.0001
0.0001
0.0001
695.6056
782.2630
782.2630
782.2630
782.2630
782.2630
782.2630
869.1811
869.1811
869.1811
869.1811
869.1811
869.1811
350.1061
350.1061
350.1061
350.1061
350.1061
350.1061
437.0242
437.0242
437.0242
437.0242
437.0242
437.0242
695.6056
695.6056
695.6056
695.6056
695.6056
0.729%
0.728%
0.728%
0.728%
0.728%
0.728%
0.728%
0.727%
0.727%
0.727%
0.727%
0.727%
0.727%
0.742%
0.742%
0.742%
0.742%
0.742%
0.742%
0.737%
0.737%
0.737%
0.737%
0.737%
0.737%
0.729%
0.729%
0.729%
0.729%
0.729%
39.731
36.608
35.790
37.784
36.071
37.656
37.349
37.963
38.447
36.076
35.708
35.225
35.938
39.122
44.035
42.778
44.949
40.094
47.463
41.135
41.089
42.188
41.089
42.691
41.730
39.932
40.565
40.220
37.661
39.616
1.195
1.080
1.069
1.096
1.072
1.095
1.090
1.039
1.045
1.014
1.008
1.002
1.012
1.764
1.849
1.828
1.863
1.783
1.906
1.577
1.576
1.593
1.576
1.601
1.586
1.198
1.206
1.203
1.166
1.193
-1.38
-9.13
-11.16
-6.21
-10.47
-6.53
-7.29
-5.77
-4.57
-10.45
-11.37
-12.57
-10.79
-2.89
9.30
6.18
11.57
-0.48
17.81
2.10
1.99
4.72
1.99
5.97
3.58
-0.88
0.69
-0.17
-6.52
-1.67
AVERAGE ======= >
S[n-1]========>
S[n-1]===[%]===>
S[AVERAGE]=====>
S[AVERAGE]=[%]==>
AVERAGE ======= >
S[n-1]========>
S[n-1]===[%]===>
S[VAVERAGE]=====>
S[AVERAGE]=[%]==>
AVERAGE ======= >
S[n-1]========>
S[n-1]===[%]===>
S[AVERAGE]=====>
S[AVERAGE]=[%]==>
AVERAGE ======= >
S[n-1]========>
S[n-1]===[%]===>
S[AVERAGE]=====>
S[AVERAGE]=[%]==>
AVERAGE ======= >
S[n-1]========>
S[n-1]===[%]===>
S[AVERAGE]=====>
S[AVERAGE]=[%]==>
39.621
1.0198493
2.57
0.4163517
1.05
36.876
0.8434348
2.29
0.3443308
0.93
36.560
1.3157308
3.60
0.5371449
1.47
43.074
3.1076325
7.21
1.2686857
2.95
41.654
0.6742501
1.62
0.2752615
0.66
3.39
6.92
-9.25
-8.47
-1.65
Table 8 (continued)
1.01
0.99
0.95
1.29
1.20
0.6028
0.6028
0.6028
0.6028
0.6028
0.6028
0.7028
0.7028
0.7028
0.7028
0.7028
0.7028
0.8028
0.8028
0.8028
0.8028
0.8028
0.8028
0.9028
0.9028
0.9028
0.9028
0.9028
0.9028
1.0028
1.0028
1.0028
1.0028
1.0028
1.0028
0.0001
0.0001
0.0001
0.0001
0.0001
0.0001
0.0001
0.0001
0.0001
0.0001
0.0001
0.0001
0.0001
0.0001
0.0001
0.0001
0.0001
0.0001
0.0001
0.0001
0.0001
0.0001
0.0001
0.0001
0.0001
0.0001
0.0001
0.0001
0.0001
0.0001
523.9424
523.9424
523.9424
523.9424
523.9424
523.9424
610.8605
610.8605
610.8605
610.8605
610.8605
610.8605
697.7786
697.7786
697.7786
697.7786
697.7786
697.7786
784.6967
784.6967
784.6967
784.6967
784.6967
784.6967
871.6148
871.6148
871.6148
871.6148
871.6148
871.6148
0.733%
0.733%
0.733%
0.733%
0.733%
0.733%
0.731%
0.731%
0.731%
0.731%
0.731%
0.731%
0.729%
0.729%
0.729%
0.729%
0.729%
0.729%
0.728%
0.728%
0.728%
0.728%
0.728%
0.728%
0.727%
0.727%
0.727%
0.727%
0.727%
0.727%
40.266
41.640
40.953
43.091
39.693
42.213
41.085
40.397
40.070
42.362
42.427
41.641
39.578
38.260
40.754
38.317
39.034
39.149
36.673
39.018
40.394
38.610
38.431
38.584
39.464
38.775
38.018
37.788
38.890
38.821
1.408
1.428
1.418
1.450
1.397
1.436
1.302
1.293
1.288
1.320
1.322
1.311
1.190
1.173
1.206
1.173
1.183
1.184
1.079
1.110
1.129
1.106
1.103
1.104
1.056
1.047
1.038
1.036
1.049
1.048
-0.05
3.36
1.65
6.96
-1.47
4.78
1.98
0.27
-0.54
5.15
5.31
3.36
-1.76
-5.03
1.16
-4.89
-3.11
-2.83
-8.97
-3.15
0.26
-4.16
-4.61
-4.23
-2.04
-3.75
-5.63
-6.20
-3.47
-3.64
41.309
1.2590249
3.05
0.5139948
1.24
41.330
0.9882595
2.39
0.4034553
0.98
39.182
0.9217383
2.35
0.3762981
0.96
38.618
1.1944575
3.09
0.4876352
1.26
38.626
0.6168569
1.60
0.2518308
0.65
AVERAGE ======= >
S[n-1]========>
S[n-1]===[%]===>
S[AVERAGE]=====>
S[AVERAGE]=[%]==>
AVERAGE ======= >
S[n-1]========>
S[n-1]===[%]===>
S[AVERAGE]=====>
S[AVERAGE]=[%]==>
AVERAGE ======= >
S[n-1]========>
S[n-1]===[%]===>
S[AVERAGE]=====>
S[AVERAGE]=[%]==>
AVERAGE ======= >
S[n-1]========>
S[n-1]===[%]===>
S[AVERAGE]=====>
S[AVERAGE]=[%]==>
AVERAGE ======= >
S[n-1]========>
S[n-1]===[%]===>
S[AVERAGE]=====>
S[AVERAGE]=[%]==>
0.93
0.97
1.02
1.05
1.12
-4.12
-4.14
-2.74
2.59
2.54
Table 8 (continued)
0.001
0.001
0.001
0.001
0.001
0.001
0.0001
0.0001
0.0001
0.0001
0.0001
0.0001
0.8692
0.8692
0.8692
0.8692
0.8692
0.8692
1.072E-01
1.072E-01
1.072E-01
1.072E-01
1.072E-01
1.072E-01
210.543
387.721
348.604
663.843
111.599
-95.492
-347.111
384.065
-339.493
392.190
399.654
-320.892
AVERAGE======== >
S[n-1]========>
S[n-1]===[%]===>
S[AVERAGE]=====>
S[AVERAGE]=[%]==>
84.754
383.49508
452.48
156.56121
184.72
Table 8 (continued)
2.60
15
A gross alpha/beta counting system MPC 2000
387
5. CONCLUSIONS
The results which were obtained in the SALMROM laboratory from the
measuring/ testing/rating and comparison data validate the use of the measuring
method, pointing out that the MPC 2000 system is correctly calibrated in
efficiency, while observing the processed testing geometries.
The system can be used for:
• Measuring radioactive alfa and beta concentrations in a wide range of
different samples: solid, liquid, filtres, aerosoles etc.;
• Monitoring radioactive alfa and beta concentrations in the environment,
biological and food samples, mineral and geological samples, radioactive
waste, materials used in the nuclear industry and its applications;
• Characterization of the content of total alfa and beta radionucleids in
different samples and screening for the selection of special samples, etc.
REFERENCES
1. Halbwertszeiten und Photonen-Emissionswahrscheinlichkeiten von häufig verwendeten Radionukliden”2005 eiwerterte und korrigierte Auflage von Ulrich Schötzig und Heinrich Schrader PhysikalischTechnische Bundesanstalt (PTB), Braunschweig.
2. SR EN ISO/CEI 17025: 2005 – Cerinţe generale pentru competenţa laboratoarelor de încercări şi
etalonări.
3. Legea 111/1996 privind desfăşurarea în siguranţă a activităţilor nucleare, republicată, cu
modificările şi completările ulterioare.
4. Manualul Calitatii al IFIN-HH, MC-00-00, ediţia în vigoare.
5. Manualul Calitatii al SALMROM, MC-FVM-100, Rev. 1, 2009, ediţia în vigoare.
6. Manualele de operare, documentaţia tehnică – Sistem de masură a radioactivităţii alfa şi beta
globale în fond scăzut model MPC – 2000.
7. Precedures manual, Environmental Measurements Laboratory, HASL - 300, U S Department of
Energy, 1992.
8. Raport de Etalonare al sistemului MPC 2000, nr. 2/2008, Cod: RE-FVM-101B, Nr. 2/2009.
9. IAEA - Update of X Ray and Gamma Ray Decay Data Standards for Detector Calibration and
Other Applications, Volume 1: Recommended Decay Data, High Energy Gamma Ray Standards
and Angular Correlation Coefficients, 2007.
10. IAEA - Update of X Ray and Gamma Ray Decay Data Standards for Detector Calibration and
Other Applications, Volume 2: Data selection, Assessment and Evaluation Procedures, 2007.