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Cyclotron Production of I-123 by Bombardment of 124Te Electroplated Target
Zhou Wei, Wang Yongxian, Yin DuanzhiShanghai Institute of Applied Physics,
Chinese Academy of Science
Nuclear process for production of 123I
Direct method: (low energy cyclotron) 121Sb(α,2n)123I, natSb(3He,xn)123I,124Te(p,2n)123I, 123Te(p, n)123I,122Te(d,2n)123I ……
Indirect method: 123Xe 123I(medium and high energy cyclotron)127I(p, 5n)123Xe, 124Xe(p, 2n)123Xe124Xe(p, pn)123Xe ……
Te target for production of I-123
Metal 124Te target2π or 4π cooling wet chemical separation Molten 124TeO2 target4π coolingdry distillation
Source for 124TeO2 lost
Target heating to liberate 123Iloss of 124TeO2:<1%Accidental melting during irradiation2π cooling systemirradiation angle: 6 ºloss of 124TeO2:3~5%
Production methodfor electroplated target
124Te electroplated Target----molten target
Irradiation
Wet chemical separation -----dry distillation
Recovery of the enriched tellurium
Quality control
Targetry Ni surface onto the Cu plate
Ni plating solution:
NiSO4·6H2O
NiCl2·6H2O
H3BO3
pH: 3~4.
TargetryNi surface onto the Cu plate
Current: 200mATime: 12 min Anode: platinum electrodeCathode: Cu plateCurrent efficiency: 90%Ni thickness: 250ug/cm2
Targetry Electroplating of enriched 124Te
Stock solution124Te 124Te O 2
KOH solutionpH: 10~11
Targetry Electroplating of enriched 124Te
Current:100mATime: 60 minThickness: 12mg/cm2
WashDry
124Te electroplated target
Irradiation
Cyclone 30 (IBA)Proton energy: 25 MeVBeam current intensity: 20~50µA Time of irradiation: 0.5~3hr 123I yield: 8.2mCi/µA h124Te loss: <1% each run
Separation of I-123 from tellunium
Dissolution of 124Te(NaOH+ H2O2)Aluminum powerHeating gentlyStream distillationPrecipitation (Te0 +Al(OH)3)FilterRadiochemical yield : >90%
Recovery of the enriched Te-124
Dissolution of power(Te0 +Al(OH)3)H2SO4 + H2O2
DistillationHypophosphorus acidPrecipitate of telluriumwashed and dried124Te recovery : >99.5%
Quality ControlRadionuclidic purity
Radioactivity concentration
Radiochemical purity
pH value
Concentration of Al & Te
Bacterial endotoxins
Result and discussionTargetthickness: Ni 250ug/cm2, Te 12mg/cm2
123I yield: 8.2mCi/µA hr124Te loss: 1% each runRadiochemical yield : >90%124Te recovery : >99.5%
Influence of beam current intensity on loss of Te
10 20 30 40 50 60 70 80 90 100 1100.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
Loss
of T
e (%
)
Beam current intensity (uA)Fig.1 Relationship between loss of Te and beam current intensity
Influence of thickness of Ni layeron loss of Te
100 150 200 250 300 350 4000.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
loss
of T
e (%
)
thickness of Ni layer (ug/cm2)Fig.2 Relationship between loss of Te and thickness of Ni layer
124Te(p,2n)123I 50uA, 1hr
Influence of thickness of Te on loss of Te
9 10 11 12 13 14 15 160.0
0.5
1.0
1.5
2.0
2.5
124Te(p,2n)123I 50uA, 1hr
loss
of T
e (%
)
thickness of Te(mg/cm2)Fig.3 Relationship between loss of Te and thickness of Te
Influence of thickness of Te on yield of 123I
10 11 12 13 14 155
6
7
8
9
10
11
124Te(p,2n)123I50uA, 1hr
yiel
d(12
3 I mC
i/uA
hr)
thickness of 124Te(mg/cm2)
Fig.4 Influence of thickness of 124Te on yield of 123I
Influence of integrated current on yield of 123I
0 50 100 150 2003
4
5
6
7
8
9
10
Yiel
d (m
Ci12
3 I/uA
hr)
Integrated current(uAhr)Fig.5 Relationship between yield of 123I and integrated current
124Te(p,2n)123I124Te target: 13mg/cm2
Specification of 123I solution
Radionuclidic purity: >98%.
Radiochemical purity: Iodide 123I >95%
Radioactivity concentration: >3700 MBq/mL.pH value: 7.5~9.0Concentration of Al: < 1ug/mLConcentration of Te: <1ug/mLBacterial endotoxins: <30EU/mL
Thank you for your attention!