Transcript Document

Radioanalytical practical at the Department of
Neutron Activation Analysis
Marja Raven
Itumeleng Ramatlhape
Ntsoaki Seaga
10.10.2008
FLNP JINR, Dubna
Supervisors
Summer School 2008 S.S. Pavlov and M.V. Frontasyeva
Introduction
Pulsed fast reactor IBR-2, Dubna
Experimental facility REGATA at
IBR-2 reactor
,3n
Ch4
Ch3
Ch0
p,n
BS
Ch2
Ch1
Z
Cd
S
BS
RCB
U
SM
DCV
L
,n
,2n
32
SU
d28
R
p,
d,n
,n
n,2n
Target
radionuclide
,pn
d,
,p
n,pn
,np
n,
d,p
n,p
d28
R1
d16
D
D
n,
D
R2
AA
CC
N
IBM
PC
CB
R3
Nuclear reactions
Ch1-Ch4 –irradiation channels, S- intermediate storage, DCV- directional control valves, L- loading unit,
RCB- radiochemical glove-cell, U- unloading unit, SU- separate unit, SM- storage magazine, R- repacking
unit, D- detector, AA- amplitude analyser, CB- control board, CC- CAMAC controller, R1-R3- the rooms
where the system is located.
The Process of Neutron Activation Analysis
NAA most commonly uses (n,γ) reactions
n(E), n/(s.cm2)
Neutron energy spectra
in irradiation channels
101143
1012
1011
10
10109
108
107
106
105
104
103
102
101
10
100
10-2-1
10
10-2 10-1 100
101
102
103
104
105
106
107
E(eV)
Thermal neutrons (<0.55 eV)
Epithermal neutrons (0.55 eV –0.1
MeV)
Fast neutrons (>0.1 MeV)
Gamma-spectra of material after
irradiation
A – pile neutron activation; B –
epithermal neutron activation
HPGe Gamma
detector
High
voltage
supply
Pre-amp
Spectroscopy
amplifier
Detector
Analogue to
digital
converter
Analyzer
Energy Calibration with Eu-152
source
Efficiency Calibration curve of HPGe Canberra
coaxial detector
Eff(E)=P1e-P2E+ P3e-P4E+ P5e-P6E+ P7E-P8
0,0035
0,0030
Data: D5111_EFFECTIVNNEW
Model: effectiveness
Weighting:
y
No weighting
Efficiency
0,0025
Chi^2/DoF
= 8.5072E-10
R^2
= 0.99908
0,0020
P1
P2
P3
P4
P5
P6
P7
P8
0,0015
0,0010
-1.20089
0.04199
-0.08214
0.03139
1.24156
0.04138
0.13819
0.73022
±0
±0
±0.24585
±0.01102
±0.23565
±0.00156
±0.00898
±0.01071
2500
3000
0,0005
0
500
1000
1500
Energy, keV
2000
Special thanks:
- Director Dmitri V. Fursaev
- Dr. M.V. Frontasyeva
- Mr. S.S. Pavlov
THANKS FOR YOUR
ATTENTION!!