Transcript POSSIBILITIES OF PRODUCTION OF TECHNETIUM SHORT …

POSSIBILITIES OF
PRODUCTION OF
TECHNETIUM SHORT-LIVED
RADIOACTIVE ISOTOPES
O.D. Maslov, S.N. Dmitriev,
A.V. Sabelnikov
Flerov Laboratory of Nuclear Reactions
JINR Dubna
Technetium has three long-lived radioactive isotopes:
97
Tc T1/2 = 2.6106 y; EC; no 
98
Tc T1/2 = 4.2106 y; -; E 745 keV, 652 keV
99
Tc T1/2=2.1105 y; -; E 90 keV
Other technetium isotopes are short-lived.
Flerov Laboratory of Nuclear Reactions
JINR Dubna
Why are technetium short-lived isotopes studied?
The dominance of 99mTc in nuclear medicine is
based on logistic convenience, image resolution and
only recently physiological authenticity of the labeled
agents. As the field of technetium pharmacology
grows to include new tracers increasing biochemical
importance, the need for quantitative imaging
becomes compelling.
One of the problems of 99Tc analysis in the
technological processing and environment is a tracer
since there are no stable Tc isotopes.
So there is the need to use the Tc short-lived
isotopes as the tracers.
Flerov Laboratory of Nuclear Reactions
JINR Dubna
Short-Lived Isotopes of Technetium
Isotope
T1/2
Decay
Using of the Tc isotopes
91mTc
3.3 m
IT, EC
+
91gTc
3.14 m
EC
+
92Tc
4.23 m
EC
+
93mTc
43.5 m
IT
2.7 h
EC,  +
52 m
EC
+
PET imaging to bear on technetium pharmacology.
The testing of radiopharmaceuticals labeled with 99mTc.
95gTc
20 h
EC
Radiochemical studies
95mTc
61 d
EC,  +
96Tc
4.3 d
EC
96mTc
52 m
EC
97mTc
91 d
99mTc
6h
93gTc
94mTc
PET
The 95mTc and 96Tc tracers are applicable to numerous fields
for medical, biological and environmental scientific studies
Tracers for environmental research
-
Nuclear medicine
Target and nuclear reaction for
production of Tc isotopes
Element
-target
Reaction
Mo
(p,n)
(p,2n)
(p,np)
(,2n)
(, xn)
(,xnp)
(d,n)
(d,2n)
(n,)
(,n)
Nb
(,n)
(,2n)
(,3n)
(d,2n)
(3He,3n)
Ru
(,n)
Rh
(p, spal.)
U
(n,f)
Tc
92
+
93m
93
+
+
+
+
94m
+
+
94
+
+
+
+
+
+
+
95m
+
+
96
+
97m
98
99m
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
Tc isotopes produced by irradiating a 0.1
mm Mo foil with an 11 MeV proton
beam
Reaction
Abund.
%
Value
(MeV)
T1/2
Decay
Y53
min
(mCi/A)
92Mo(p,
n) 92Tc
14.8
-8.8
4.4 min
92%  +
1.4
94Mo(p,
n) 94mTc
9.3
-5.1
53 min
72%  -
1.7
94Mo(p,
n) 94Tc
9.3
-5.0
293 min
89%
EC
90
95Mo(p,
n) 95mTc
15.9
-2.5
62d
96%
EC
0.64
95Mo(p,
n) 95Tc
15.9
-2.4
20.1 h
100%
EC
130
96Mo(p,
n) 96Tc
16.7
-3.7
4.3 d
100%
EC
60
9.6
-7.7
6.0 h
99% IT
109
100Mo(p,
2n) 99mTc
Abund.(%) natural isotopic abundance of molybdenum,
Y
, production yield for a 53 min irradiation.
Yield of technetium
isotopes in Mo(p, n) reaction after end of
irradiating
Isotopic
c o m p o s i t i o n, %
100
100
95m
99m
96g
80
80
96m
94g
60
60
95m
94m
40
40
94g
20
20
94m
0
0
0
1
2
3
D e c a y t i m e, h
enriched 94Mo
4
0
1
2
Decay
3
t i m e, h
natural Mo
Flerov Laboratory of Nuclear Reactions
JINR Dubna
4
Tc production yields with 
and 3He beams
Reaction
Q
(MeV)
T1/2
Yield(mCi/
A)
93Nb(,
3n)94mTc
-25
53 min
2.1
93Nb(,
3n)94Tc
-25
293 min
11
93Nb(,
2n)95Tc
-15
20 h
43
93Nb(,
n)96Tc
+6
4.3 d
11
93Nb(3He,
2n)94mTc
-4
53 min
4.6
93Nb(3He,
2n)94Tc
-4
293 min
12
92Mo(,
2n)94Ru
-18
52 min
1.7
92Mo(,
2n)95Ru
-8
1.6 h
2.2
natMo(,
xn)97Ru
-
2.9 d
8
natMo(,
xnp)94mTc
-
53 min
0.5 (direct)
natMo(,
xnp)94Tc
-
293 min
2.2
natMo(,
xnp)95Tc
-
20 h
0.8 (direct)
natMo(,
xn)101Tc
-
14 min
0.14
Thick target yields
Alpha irradiation (33 MeV) of the many stable isotopes of molybdenum leads to a
considerable number of technetium and ruthenium products through the (, xnp) and
(, xn) reactions, respectively.
Thus the purity of isotope is determined the choice target, bombarding
particles and their energy, time of irradiation and cooling and radiochemical
operations for separation and concentration of final isotope.
Microtron MT-25
Flerov Laboratory of Nuclear Reactions
JINR Dubna
Main Parameters of MT-25
Microtron
Maximum electron energy, MeV
Energy range, MeV
Pulsed beam curren, A
Pulsed current duration, s
Beam spot diameter, mm
Monohromatization, keV
Power consumption, kW
Gamma beam
Gamma-quanta flux, s-1
Bremsstrahlung dose (1 m), Gy m2 s-1
Neutron beam
Density of thermal neutron flux
pps cm-2
Density of ephi-thermal neutron flux
pps cm-2
Density of fast neutron flux, s-1
Flerov Laboratory of Nuclear Reactions
JINR Dubna
25
4-25
20
2.2 10-6
5
50
20
1014
1.5
109
5. 107
1012
MICTROTRON MULTIPURPOSE ELECTRON ACCELERATOR
CHARACTERISTIC OF PRIMARY AND SECONDARY BEAMS
 Electron beam as a primary beam
 Gamma beam
 Neutrons - after (,n) on heavy elements
 Mixed ,n field
1. GAMMA ACTIVATION ANALYSIS
2. NEUTRON ACTIVATION ANALYSIS
3. RADIOISOTOPE PRODUCTION
 Nuclear medicine
 Biomedical research
 Radioecological research
Flerov Laboratory of Nuclear Reactions
JINR Dubna
Production of the 99Mo/99mTc generator
Tc
99m
Mo
98
(,n)
-
99 100
(,p)
Nb
(n,)
99mg
(n,2n)
99mTc
(T1/2 = 6.02 h; IT (100%); E = 140.5 keV(87.7%)
Reaction
T1/2
Eth, MeV
max, mb
Em, MeV
, MeV
Ab.
100Mo(,n)99Mo
66.2 h
9.1
170
16.0
7.3
9.63
100Mo(,p)99Nb
15 s
16.5
67
20.4
4.7
100Mo(,p)99mNb
2.6 m
16.9
16
22.0
4.5
100Mo(n,2n)99Mo
66.2 d
8.3
98Mo(n,)99Mo
66.2 d
137th
Flerov Laboratory of Nuclear Reactions
JINR Dubna
24.1
Scheme of the irradiation of the target
block
100
Mo (nat Ru)
 8 mm
Au, (Ag)
W
AL
Scheme of the irradiation of the
assemblage of natMo-foils
Yield of
99Mo
Photonuclear reaction:
100Mo(,n)99Mo
2.2 kBq (99Mo) = 1 mg (100Mo) * 25 MeV -rays * 1 A * 1 h
1 550 mCi (99Mo) = 1 g ( 100Mo) * 25 MeV -rays * 25 A * 100 h
2 1.5 Ci (99Mo) = 1 g ( 100Mo) * 25 MeV -rays * 500 A * 50 h
Production of the
(, n)
95
Ru
96
Ru
1.65 h
5.52
 2.9
95
m
60 d
4
96
Tc
g
20 h
Tc
m
52 m g4.3 d
 100
97.1
95
96
Mo
15.92
Flerov Laboratory of Nuclear Reactions
JINR Dubna
95m, gTc
Yield of
95m, 95gTc
Photonuclear reaction:
96Ru(,
n)95Ru95m, gTc
• 0.2 mCi (95mTc) = 1 g (96Ru)25 MeV20 A 100 h
• 0.3 Ci (95gTc) = 1 g (96Ru)  25 MeV20 A  100 h
Flerov Laboratory of Nuclear Reactions
JINR Dubna
natMo(,
n) 99Mo
30
EL, I=500 A
Thin targ. 99Mo 10-2
9
100Mo(,
n) 99Mo
22
Microtron, th. t.99Mo,
estimate: 2.7 10-3
6,7
10
The MT-25 of FLNR
99mTc
natMo
10g(,
100Mo(,
n)99Mo
n)99Mo
390
95mTc
T1/2= 6 h
25
99Mo
1.4 10-3
12
25
99Mo
6 10-2
12
T1/2=60 d /95Тc T1/2=20 h
n)95Ru T1/2
1.65h
natRu(,
(natRu) 6 10-6
(Y=7.2 kBq)95mTc
(96Ru) 10-4
95Tc
(natRu) 1.6 10-2
(96Ru) 0.3
97mTc
T1/2=91 d
n)97Ru T1/2
2.9d
(natRu) 4 10-8
(Y=50 Bq)97m,gTc
(98Ru) 2.3 10-6
natRu(,
Yields of the technetium short-lived
isotopes in (p, xn), (, xn), (d, xn), (3He,
xn) and (, n) reactions
100
Mo(p,n)
Mo(p,2n)
g
Theor.
g
Tc
10
Mo(p,n) Tc
m
Nb(,n)
Mo(p,2n) Tc
g
Mo(,pn) Tc
Yield, mCi/Ah
nat
m
Mo(,2n)
nat
Mo(,xnp)
1
Mo(p,n)
Tc
Nb(,2n)
nat
m
Mo(d,2n) Tc
99
Mo
m,g
Nb(,3n) Tc
Mo(p,n)
3
100
Mo(,n);25MeV
0,1
nat
Nb(,2n)
g
Ru(,n) Tc
96
m
-4
Ru(,n) Tc;10
0,01
Mo(,n);30 MeV
1E-3
92
93
94
95
96
97
98
99
Tc, A
Flerov Laboratory of Nuclear Reactions
JINR Dubna
Nb( He,3n)
95
95m,g
99
99m
Ru(,n) Ru >
Mo(,n) Mo >
Tc
Tc
Summary