Alternative production routes and new separation

methods for no-carrier-added 163HoSusanta Lahiri, Moumita Maiti

Saha Institute of Nuclear Physics, Kolkata, India

&

Zoltán Szűcs, Sandor Takacs

Institute of Nuclear Research of H.A.S.

Debrecen, Bem tér 18/C

HUNGARY

163Ho: How to produce?

Proton induced reaction

natDy(p,xn) 163Ho σ ~350 mb at 19 MeV

Contributors:

163Dy (24.9%)(p,n)163Ho (σ~0.4 mb)164Dy (28.2%)(p,2n)163Ho (σ~1254 mb)

5 10 15 20 250

100

200

300

400

500

600p+natDy

Ho-163

Ho-162

Projectile Energy [MeV]

Cros

s se

ction

[mb]

Calculations by Maiti et al.

Main reaction: 163Dy(p,n)163Ho Side reactions: 158Dy)p,2n)157Ho→157Dy→157Tb 160Dy(p,2n)159Ho→159Dy 160Dy(p,2p)159Dy 156Dy(p,3n)154Ho→154Dy

161Dy(p,a)158TbRadiochemical separation of 163Ho is recommended! 163Dy(p,a)160TbEnriched target material is preferable!

Calculations by Szucs et al.

Theoretical cross sections of

163Dy(p,n)163Ho and 163Dy(d,2n)163Ho

Calculations by Szucs et al.

Cross section curves of the potential nuclear reactions

5 10 15 20 25 300

100

200

300

400

500

600

700

800

900

1000

163Dy(p,n)163Ho

163Dy(d,2n)163Ho

Energy (MeV)

Cro

ss

se

ctio

n (

mb

)

5 10 15 20 25 300

100

200

300

400

500

600

700

800

900

1000

163Dy(p,n)163Ho

163Dy(d,2n)163Ho

164Dy(p,2n)163Ho

164Er(p,2n) TENDL-2011

164Er(p,x)163Tm exp

Energy (MeV)

Cro

ss

se

ctio

n (

mb

)

Calculations by Szucs et al.

Thick target yields and prices of target materials

Nuclear reaction Energy range [MeV]

Activity [kBq]

thickness [m]

price of target [kUSD]

163Dy(p,n)163Ho 6-14 614 471 1,2 163Dy(p,n)163Ho 2-20 875 1103 2,7 163Dy(d,2n)163Ho 4-20 3600 661 1,6 163Dy(d,2n)163Ho 4-30 5000 1350 3,3 164Dy(p,2n)163Ho 8,5-30 9800 2000 4,9 164Er(p,2n)163Tm 10,7-28,7 12000* 1620 61,9

*reached by decay chain of 163Tm 163Er 163Ho

Calculations by Szucs et al.

Contaminating isotopes

-10.0 10.0 30.01E-02

1E+01

1E+04

Energy (MeV)

Cro

s

s

se

cti

on

(mb

)

0.0 5.0 10.0 15.0 20.0 25.0 30.01E-02

1E-01

1E+00

1E+01

1E+02

1E+03

natDy(p,x)158Tb

natDy(p,x)157Tb cum

natDy(p,x)159Dy

natDy(p,x)163Ho

164Dy(p,g)165Ho

Energy (MeV)

Cro

ss s

ecti

on (

mb

)

Calculations by Szucs et al.

Irradiation of natDy by proton

Energy 163Ho 157Tb 158Tb 159Dy

range [MeV] [MBq] [MBq] [MBq] [MBq]

5-11 0,20 0,00 0,00 0

5-18 1,74 3,81 0,04 968

5-28.7 2,93 18,27 1,10 20732

Calculations by Szucs et al.

Comments

1. The highest yield give the (p,2n) reaction2. Er irradiation is NOT preferred because of the side reactions, producing the stable

165Ho as well as the radioactive 166Ho!!!!3. The enriched target of 164Dy has to be used. In other case during the irradiation of the

natDy the 157-158Tb and 159Dy will give us extremely high contamination4. During the irradiation of enriched 164Dy we will get the stable 165Ho too by the 164Dy(p,

γ)165Ho reaction. However this amount is 2 magnitude less, than 163Ho. 5. The calculation of cross section curve of 157Tb contains all possible reaction for 157Ho,

157Dy and 157Tb, as well as for 159Dy also contains all possible reaction for 159Ho and 159Dy.

6. Due to the 10 times higher yield of the (p,2n) reaction than the (p,n) reaction not necessary 1800 hours irradiation time to get 1 MBq 163Ho, approximately. Looks that is enough 180 hours, 10 times less, therefore the irradiation cost in cyclotron also can be 10 times less, it means that is 50kEuro, approximately, which is comparable with the irradiation on reactor!!!!!

7. The Debrecen cyclotron can't produce the 30MeV proton beam.

p+ Dy2O3

Irradiation Parameters: (i) Projectile – p, (ii) Ep = 19 MeV, (iii) current: 700 nA, (iv) time of irradiation: 10 h

Two targets were irradiated in stack with the following configuration

There is no way to monitor Ho-163 by monitoring its nuclear properties.

Separation of Dy and Ho is difficult.

Very long time is required to rich the saturation activity.

-induced reactions

natDy(α, xn) 163Er () 163HoCalculations by Maiti et al.

+Dy2O3

10 15 20 25 30 35 40 45 500

100

200

300

400

500

600+natDy

Er-165, 10.3hEr-163, 75mEr-161, 3.24hEr-160, 28.6h

Energy, MeVCr

oss

seci

on, m

b

natDy(α, xn) 163Er () 163Ho(σ ~500 mb at 40 MeV)

Irradiation parameters:

Projectile : α EP = 40 MeVfirst target: 1 µA, 7 h irradiation second target: 3 µA, 11 h irradiation

Exhaustive Chemistry !!Experiment and Calculations by Maiti et al.

RadioChemical Separation of Er and Dy

0.1 0.2 0.3 0.4 0.50

20

40

60

80

100

at 1% HDEHP

DyEr

[HCl], M

Extr

actio

n, %

161Er was used as monitor of Er in the radiochemical separation

&Dy was measured by ICP-OES

Technique – Liquid liquid extraction Reagents: di-(2-ethylhexyl) phosphoric acid (HDEHP) dissolved in cyclohexane (Organic phase) & HCl (aqueous phase)

HCl : 0.2 M & HDEHP 1%Extraction: Dy 48.8%

Er 84%

Separation scheme

Experiment by Maiti et al.

Li-induced reaction

159Tb(7Li, 3n) 163Er (σ ~312 mb at 31 MeV)

25 30 35 400

200

400

600

800

1000

12007Li+159Tb

163 Er

Energy [MeV]

Cros

s se

ction

[mb]

Calculations by Maiti et al.

Irradiation

Irradiation parameters:

(i) Projectile – 7Li

(ii) EP = 31 MeV

(iii) current: 150 nA(iv) time of irradiation: 11 h

No successful results have been achieved using HDEHP

Calculation for natDy(p,xn) reaction:

For a sample thickness: 4 mg/cm2

No. of 163Ho (via 163Er) will be = 2.5x1010 atoms/A-h

For enriched target it will increase by factor of 2.

For 10 A, 100 h irradiation (one target): 2.5 x 1013 atoms

Maiti et al.

Calculation for Dy(,xn) reaction:

For a sample thickness: 4 mg/cm2

No. of 163Ho (via 163Er) will be = 2x1010 atoms/A-h

In 6 h, irradiation time = 1.2x1011 atoms

20 A current, 5 targets in a row, 6 h irradiation time

1.2 x 1013 atoms

Maiti et al.

Calculation for 159Tb(7Li,3n) reaction:

For a sample thickness: 4 mg/cm2

No. of 163Ho (via 163Er) will be = 4x109 atoms/A-h

In 6 h, irradiation time = 2.4x1010 atoms

20 A current, 5 targets in a row, 6 h irradiation time

2.4 x 1012 atoms

Maiti et al.

Consequences!

163Ho can be produced by charged particle activation through direct or indirect way

However, separation of Ho from the target matrix is extremely difficult due to the similar chemical properties of lanthanides

Therefore, it needs special attention towards the purification procedure

In order to ensure the production of 163Ho nuclear properties can not be exploited as it behaves like stable isotope

ECHo CollaborationThis collaboration has been formed on 29th June, 2012

Participants: 10 Institutes from 5 countries

Thank you….

Future Plan from SINP and ATOMKI Group

1. Will apply for beam time in VECC, Kolkata and in Atomki, Hungary

2. Verification of theoretical data as much as possible. 3. Storing Ho-163 for future use4. Development of new separation techniques based

on HPLC