ELBE Neutron Source IAEA TC Meeting “Nuclear Data for IFMIF”, FZ Karlsruhe, October 4-6, 2005...

ELBE Neutron Source

IAEA TC Meeting “Nuclear Data for IFMIF”, FZ Karlsruhe, October 4-6, 2005

Klaus SeidelTechnische Universität Dresden

IAEA TC Meeting “Nuclear Data for IFMIF”, FZ Karlsruhe, October 4-6, 2005 K. Seidel, TU Dresden

ELBE at FZ Rossendorf

Electron Linac for beams with highBrilliance and low Emittance

Neutron laboratory of TUDwith photon-neutron and D-T neutron sources


Deuteron beam: Ed = 300 keV, Id = 10 mA on TiT target,

continuous operation with up to 1012 neutrons/s,

pulsed operation (1 mA) 10 s …100 s with

repetition rate of 1 Hz … 1 kHz.

Electron beam: Ee = 40 MeV, Ie = 1mA on W target

for bremsstrahlung and photo-neutron production

7·1013 neutrons/s


Intension for fusion neutronics:production of high neutron fluxes with spectral distributiontypical for fusion assemblies

Example: flux spectrum in cells of the HCPB DEMO blanket (BBxxx, U. Fischer)

10-7 10-6 10-5 10-4 10-3 10-2 10-1 100 101 102

10-4

10-3

10-2

10-1

100

101

102

103

104

105

Moderator PE with 10% B D = 3 cm

normalized to a fluence of 1 cm-2

BB37/11

BB37/6

BB37/11

F(E

) / (

MeV

-1 c

m-2)

E / MeV

Continuous part by the photo-neutronsource with moderator and absorber,Ee = 30 MeV

Peak of fusion neutrons by the D-Tgenerator

IFMIF: Neutron energies above 15 MeV are of particular interest for assessing the data base.


Flux spectrum from the photo-neutron source at the maximum electron energy of Ee = 40 MeVMCNPX model of the source

0 10 20 30 4010-12

10-11

10-10

10-9

10-8

10-7

10-6

10-5

10-4

n(E

) / (

Me

V-1 c

m2 )

E / MeV

Flux spectrum at sample position per one electron

With Ie = 1 mA the flux in the sample is 2.3·1011 cm-2·s-1.

The fluence of neutrons with E > 15 MeV applied during tirr = 10 h amounts to 1.04·1012 cm-2.


Comparison with the parameters for the EFDA Task “Validation experiment of -activities of Ta irradiated in fusion peak neutron spectrum”

During tirr = 8.8 h a fluenceof 7.9·1011 cm-2 was appliedand all -activities that areimportant up to the recycling-limit of the material were measured with a HPGe-spectrometer and analysed with the European Activation System EASY (R.A. Forrest)

EASY2005

calculationD-T

neutronsPhoto-

neutrons

Lu-176m

Lu-177

Lu-178

Lu-178m

Hf-180m

Hf-181

Ta-178

Ta-178m

(Ta-179)

Ta-180

Ta-182

Ta-182m

-

(0.070)

32.2

16.7

7.61

1.48

-

-

(0.086)

4.2·104

6.09

4.88

2.27

1.03

142.

79.5

244.

7.77

496

63.6

(33.2)

5.2·105

5.0·105

2.2·106

Specific activities [Bq/g] produced by


Ta-181(n,2na)Lu-176C

ross

sec

tion

(b)

Energy (eV)

0.0E+00

2.5E-03

5.0E-03

7.5E-03

1.0E-03

0.0E+0 1.5E+7 3.0E+7 4.5E+7 6.0E+7

dE)E()E( tested by the activity measurement

Cross section data from EASY-2005


Ta-181(n,n'a)Lu-177

Cro

ss s

ecti

on (

b)

Energy (eV)

0.0E+00

3.0E-04

6.0E-04

9.0E-04

1.2E-03

0.0E+0 1.5E+7 3.0E+7 4.5E+7 6.0E+7


Ta-181(n,a)Lu-178

Cro

ss s

ecti

on (

b)

Energy (eV)

0.0E+00

5.0E-04

1.0E-03

1.5E-03

2.0E-03

0.0E+0 1.5E+7 3.0E+7 4.5E+7 6.0E+7


Ta-181(n,d)Hf-180C

ross

sec

tion

(b)

Energy (eV)

0.0E+00

5.0E-03

1.0E-03

1.5E-02

2.0E-02

0.0E+0 1.5E+7 3.0E+7 4.5E+7 6.0E+7


Ta-181(n,n'p)Hf-180

Cro

ss s

ecti

on (

b)

Energy (eV)

0.0E+00

2.0E-02

4.0E-02

6.0E-02

8.0E-02

0.0E+0 1.5E+7 3.0E+7 4.5E+7 6.0E+7


Ta-181(n,p)Hf-181

Cro

ss s

ecti

on (

b)

Energy (eV)

0.0E+00

2.5E-03

5.0E-03

7.5E-03

1.0E-03

0.0E+0 1.5E+7 3.0E+7 4.5E+7 6.0E+7


Ta-181(n,4n)Ta-178C

ross

sec

tion

(b)

Energy (eV)

0.0E+00

2.5E-01

5.0E-01

7.5E-01

1.0E+00

0.0E+0 1.5E+7 3.0E+7 4.5E+7 6.0E+7


Ta-181(n,3n)Ta-179C

ross

sec

tion

(b)

Energy (eV)

0.0E+00

5.0E-01

1.0E+00

1.5E+00

2.0E+00

0.0E+0 1.5E+7 3.0E+7 4.5E+7 6.0E+7


Ta-181(n,2n)Ta-180C

ross

sec

tion

(b)

Energy (eV)

0.0E+00

3.8E-01

7.5E-01

1.1E+00

1.5E+00

0.0E+0 1.5E+7 3.0E+7 4.5E+7 6.0E+7


Conclusions

At the ELBE laboratory a photo-neutron source is under construction that will produce 7.1·1013 neutrons/sec with energies ranging up to 30 MeV.

For the neutron energy range 15 MeV < E < 30 MeV fluences of 1012 neutrons/cm2 can be applied in samples arranged close to the source.

Ta was used - as an example of a typical heavy nucleus - to investigate the nuclear reactions that can be induced by these neutrons.

With HPGe-spectroscopy the -activities produced by the reactions (n,4n), (n,p), (n,d), (n,n’p), (n,), (n,n’), (n,2n), as well as (n,2n), (n,), can be measured, and the cross-section integrals obtained in this way, could be used for validating the evaluated data of the reactions in libraries.

ELBE Neutron Source IAEA TC Meeting “Nuclear Data for IFMIF”, FZ Karlsruhe, October 4-6, 2005...

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