BEAM INTENSITIES WITH EURISOL

M. Valentina Ricciardi

GSI, Darmstadt, Germany

LAYOUT

"Blocks of knowledge" to be put together to estimate RIB intensities:

1) Set-up

2) Production cross-sections

3) Production rates

4) Efficiencies

5) Possible combination of ISOL + IN-FLIGHT methods

These "blocks of knowledge" are not uncorrelated.

How to proceed?

1. We go through each block and see what we know

2. Provide this information to the user in a simple, accessible way (www)

SET-UPPrimary beam

Standard option: 1 GeV protons:● on direct target (100 kW)● on converter target (4-5 MW)

Additional possibilities (compatible with the baseline driver accelerator):● 2 GeV 3He● 250 MeV deuterons● heavier ions with A/Q = 2 up to 125 MeV/u

Target

Direct target Protons interact directly with the target material

Indirect target Spallation neutron source (most of the heat load) Production target (few-MeV neutrons)

Which nuclear reactions are of interest assuming the above set-up?

Direct-target option

Spallation-evaporation with ≤ 1 GeV protonsSpallation-fission with ≤ 1 GeV protonsFission with secondary neutrons

Indirect-target option

Fission with few-MeV neutrons

PRODUCTION CROSS SECTIONS

Experimental data taken at the FRS at GSI

Features of spallation reactions

Spallation-evaporation produces nuclides reaching from the projectile to about 10 to 15 elements below (a few of them are neutron-rich, most of them are neutron-deficient)

Spallation-fission (from Th, U) produces neutron-rich nuclides up to Z=65.

IMF (intermediate-mass fragments)

Fission fragments

Evaporation residues

PRODUCTION CROSS SECTIONS

P. Napolitani J. Taieb, M. Bernas, V. Ricciardi

The region on the chart of the nuclides covered by evaporation residues extends with increasing

energy available in the system

Experimental data taken at the FRS at GSI Energy dependence

Useful to:

• Fill gaps in target mass

• Enhance the production of IMF

PRODUCTION CROSS SECTIONS

B. Fernandez

T. Enqvist

T. Enqvist

Fission. Model Calculation (ABLA)

PRODUCTION CROSS SECTIONS

K. H. Schmidt, A. Kelić

PRODUCTION CROSS SECTIONSSpallation. Model Calculation (ABRABLA)

IN-TARGET PRODUCTION (production rates)

Additional things enter into the game:

a. Target thickness, materialb. secondary projectiles (mostly neutrons)c. decay pattern

Important: target material should be feasible!

U. Köster

IN-TARGET PRODUCTION (production rates)

Residue production in thick-spallation targets (D. Ridikas)

J.-C. David et al, Internal report DAPNIA-07-59, June 2007

Fission residue: Evaporation residue:

Experiment: at Dubna, Pohorecki et al, NIMA 2006

Calculations: MCNPX2.5.0 + CINDER'90

660 MeV p30.8 cm natPb

Optimization of in-target yields: Direct targets

Optimum target: Pb Optimum energy: 1 GeVOptimum target length: ~18 cm? (extraction efficiency)

Case 183Hg

Courtesy of S. Chabod

IN-TARGET PRODUCTION (production rates)

EFFICIENCIES

Specific and precise information on the efficiency, nucleus by nucleus(CERN/ISOLDE)

On progress

In the meantime, profiting of the valuable database(*) of yields at ISOLDE, a work of Lukić gives anOverview on the overall extraction efficiency(GSI)

(*) H.-J. Kluge, Isolde users guide, CERN, Geneva, 1986, web: http://isolde.cern.ch

EFFICIENCIES

Correlation of ISOL yields with isotope half-life

Comparison of ISOLDE-SC yields to in-target production rates

Ratio yield/produced → overall extraction efficiency for the nuclide

S. Lukić et al.

EFFICIENCIES

Same general behavior found in many cases.

0

21

s

21

t

t1

t

S. Lukić et al.

EFFICIENCIESK.H. Schmidt

EFFICIENCIES

Can we extract some

general tendency from the measured

data?

...work in progress

K.H. Schmidt

J. Benlliure et al

GSI experiment S294 (November 2006)

Participating institutes:Universidad de Santiago de Compostela, SpainCentre d’Etudes Nucleaires Bordeaux-Gradignan, FranceWarsow University, PolandGSI Darmstadt, GermanyVINCA-Institute Belgrade, SerbiaInstitute of Physics, Bratislava, Slovakia

TWO-STEP REACTION: ISOL + IN-FLIGHT

What is cold fragmentation

Two-step schemes: fission + cold fragmentation

Production of medium-mass neutron-rich nuclei

1. Produce 132Sn via fission in uranium target

2. Use cold fragmentation of 132Sn to produce medium-A neutron-rich nuclei

TWO-STEP REACTION: ISOL + IN-FLIGHT

Experimental setup at FRS

GSI experiment S294 (November 2006)

S0-S2: 238U(950 A MeV) + Be 132Sn

S2-S4: 124-132Sn + Be X

A/A ~ 1 10-3

B/~ 3 10-4 ToF ~ 100 psL ~ 36 m

B/~ 3 10-4 ToF ~ 72 psL ~ 18 m A/A ~ 1.3 10-3

Z

BAcm

e

0

Z2 ~ E

TWO-STEP REACTION: ISOL + IN-FLIGHT

Fragmentation of 132Sn (Preliminary results)

Fragmentation of 132Sn on BeD. Perez and D. Dragosavac

TWO-STEP REACTION: ISOL + IN-FLIGHT

Preliminary cross sections are available

Energy of the post accelerator

Charge state can cause impurity

TWO-STEP REACTION: ISOL + IN-FLIGHT

BEAM-INTANSITY DATA-BASE

Courtesy of Wojtek Gawlikowicz, Univ. Warsaw

http://www-w2k.gsi.de/eurisol-t11http://www.slcj.uw.edu.pl/~wojtek/eurisol_database.php

• Consistent description of nuclide production

• Calculations of in-target yields in progress

• Study of the extraction efficiencies in progress

• Feasibility of the two-step reaction scheme experimentally proven

• EURISOL beam-intensities data-base in progress

CONCLUSIONS

Beam intensities with EURISOLEURISOL DS Task 11

Task leader: Karl-Heinz Schmidt, GSI-Darmstadt

Participants and contributors: ISOLDE-CERN, CEA/Saclay, University of Jyväskylä, University of Warsaw, IoP Bratislava, GSI-Darmstadt, University Santiago de Compostella, Khlopin Radium Institute, VINČA-INS Belgrade