BEAM INTENSITIES WITH EURISOL

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BEAM INTENSITIES WITH EURISOL
M. Valentina Ricciardi





GSI, Darmstadt, Germany
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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)
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SET-UP

• Primary 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)

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PRODUCTION CROSS SECTIONS
Which nuclear reactions are of interest
assuming the above set-up? Direct-target
option Spallation-evaporation with 1 GeV
protons Spallation-fission with 1 GeV
protons Fission with secondary neutrons Indirect
-target option Fission with few-MeV neutrons
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PRODUCTION CROSS SECTIONS
Features of spallation reactions
Experimental data taken at the FRS at GSI
Evaporation residues
Fission fragments
IMF (intermediate-mass fragments)
P. Napolitani J. Taieb, M. Bernas, V.
Ricciardi

• 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 Z65.

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PRODUCTION CROSS SECTIONS
Energy dependence
Experimental data taken at the FRS at GSI
B. Fernandez T. Enqvist T. Enqvist
The region on the chart of the nuclides covered
by evaporation residues extends with increasing
energy available in the system

• Useful to
• Fill gaps in target mass
• Enhance the production of IMF

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PRODUCTION CROSS SECTIONS
Fission. Model Calculation (ABLA)
K. H. Schmidt, A. Kelic
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PRODUCTION CROSS SECTIONS
Spallation. Model Calculation (ABRABLA)
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IN-TARGET PRODUCTION (production rates)

• Additional things enter into the game
• Target thickness, material
• secondary projectiles (mostly neutrons)
• decay pattern

Important target material should be feasible!
U. Köster
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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
Experiment at Dubna, Pohorecki et al, NIMA
2006 Calculations MCNPX2.5.0 CINDER'90
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IN-TARGET PRODUCTION (production rates)
Optimization of in-target yields Direct targets
Courtesy of S. Chabod
Case 183Hg
Optimum target length 18 cm? (extraction
efficiency)
Optimum target Pb
Optimum energy 1 GeV
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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 Lukic gives an Overview on the overall
extraction efficiency (GSI) () H.-J. Kluge,
Isolde users guide, CERN, Geneva, 1986, web
http//isolde.cern.ch
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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. Lukic et al.
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EFFICIENCIES
Same general behavior found in many cases.
S. Lukic et al.
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EFFICIENCIES
K.H. Schmidt
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EFFICIENCIES
K.H. Schmidt
Can we extract some general tendency from the
measured data? ...work in progress
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TWO-STEP REACTION ISOL IN-FLIGHT
J. Benlliure et al GSI experiment S294
(November 2006)

What is cold fragmentation
Participating institutes Universidad de Santiago
de Compostela, Spain Centre dEtudes Nucleaires
Bordeaux-Gradignan, France Warsow University,
Poland GSI Darmstadt, Germany VINCA-Institute
Belgrade, Serbia Institute of Physics,
Bratislava, Slovakia
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TWO-STEP REACTION ISOL IN-FLIGHT

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
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TWO-STEP REACTION ISOL IN-FLIGHT
Experimental setup at FRS GSI experiment S294
(November 2006)

S0-S2 238U(950 A MeV) Be ? 132Sn
Z2 DE
S2-S4 124-132Sn Be ? X
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TWO-STEP REACTION ISOL IN-FLIGHT
Fragmentation of 132Sn (Preliminary results)

Fragmentation of 132Sn on Be
D. Perez and D. Dragosavac
Preliminary cross sections are available
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TWO-STEP REACTION ISOL IN-FLIGHT
Energy of the post accelerator Charge state can
cause impurity
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BEAM-INTANSITY DATA-BASE
Courtesy of Wojtek Gawlikowicz, Univ. Warsaw
http//www-w2k.gsi.de/eurisol-t11 http//www.slcj.
uw.edu.pl/wojtek/eurisol_database.php
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CONCLUSIONS

• 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

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Beam intensities with EURISOL EURISOL 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, VINCA-INS
Belgrade