EURISOL – Task 11 meeting 2007 S. Chabod 1

OUR CONTRIBUTION INSIDE EURISOL TASK 11

OPTIMIZATION OF IN-TARGET NUCLEI YIELDS

Target parameters:• material (Al2O3, Pb…)• density (alloy, porosity…)• radius (0.9 cm to 2.55 cm)• length (8 cm to 125 cm)

Direct target

Spallation target

Nuclei of interest:• NuPECC : Ar, Be, Fe, Ga, Kr, Ni, Sn• Additional: Hg, Li, Mg, Ne, etc.

On-line nucleiextraction

Beam parameters:• power• particle type (p, t, He…)• energy• gaussian parameter

Incident beam(gaussian profile)

Simulations with multiple parameters

target parameters beam parameters

Simulations with multiple parameters

target parameters beam parameters models and codes (MCNPX, CINDER, etc.)

Simulations with multiple parameters

target parameters beam parameters models and codes (MCNPX, CINDER, etc.) many nuclei of interest

Simulations with multiple parameters

target parameters beam parameters models and codes (MCNPX, CINDER, etc.) many nuclei of interest

Construction of an easy-access database for all simulated nuclei yields

Simulations with multiple parameters

target parameters

Simulations with multiple parameters

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APPLICATION TO DIRECT TARGETS: 183Hg and 11Be case

INPUT PARAMETERS

• incident particle: proton• energy: 0.5 to 2 GeV• 3 targets: Pb, Ta, UCx• gaussian parameter: R/3• code: MCNPX2.5• model: INCL4/ABLA• contribution: n > 20 MeV preliminary results

BEST TARGET: Pb

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183Hg case (II)

BEST PROTON ENERGY AT CONSTANT

POWER: 1 GeV

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183Hg case (III)

+ 50 %

+ 64 %

+ 26 %

+ 11 %

Nuclei extraction efficiency decreases with volume

BEST LENGTH: 18 cm?

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183Hg case (IV)

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APPLICATION TO DIRECT TARGETS: 11Be case

INPUT PARAMETERS

• incident particle: proton• 3 targets: Al2O3, SiC, UCx• energy: 0.5 to 2 GeV• gaussian parameter: R/3• code: MCNPX2.5• model: INCL4/ABLA• contribution: n > 20 MeV preliminary results

BEST TARGET: ?

Si componentO component

Al component

C component

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11Be case (II)

BEST TARGET:Al2O3

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11Be case (III)

BEST PROTON ENERGY AT CONSTANT

POWER: 1 GeV

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11Be case (IV)

Nuclei extraction efficiency decreases with volume

BEST LENGTH: 75 cm?

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11Be case (V)

EURISOL – Task 11 meeting 2007 S. Chabod 11

SUMMARY & OUTLOOK

Development of a methodology for in-target yields optimization

MCNPX/CINDER simulations progressive construction of a database for simulated nuclei yields Implementation of simple analysis programs for a fast navigation into the database content use of the database for target design optimization (examples of 183Hg or 11Be)

Extension of the methodology to additional direct targets (ex: Nb) and two- staged (fission) targets

Relevance of simulation results is conditioned by the relevance of spallation models (especially for light targets) and completeness of cross section libraries Final steps towards target design optimization will require ion extraction efficiencies

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Outlook (continued)

 a) we contributed already in the double stage target for 6He beam production, namely p+W-->xn+Be. This work was already reported.

b) we made some preliminary calculations on an alternative production of fission fragments using solid target-converter, namely p+Wxn+UCx. One could also try to work on d+Li,Be xn+UCx. c) we did some calculation also in the case of presently « reference » MMW target p+Hgxn+U235, U238, and Th232 resulting in in-target fission yield distributions. We have the numbers and should report on that by the end of this year. d) Today there is a new design of the MMW target station based on MAFF concept. As our last contribution we will provide in this case different yields from p+Hgxn + various targets (U235, U238, Th232, and BeO). This we will be able to report early next spring.

S. Chabod will leave CEA Saclay on 1 October we look for another PostDoc candidate to continue this work!