The ISOLDE yield database Measured secondary beams intensities at ISOLDE

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The ISOLDE yield database Measured secondary
beams intensities at ISOLDE

• Pierre Delahaye for the ISOLDE collaboration

EURISOL DS Task 11 kick-off meeting, GSI,
Darmstadt 18/03/05
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Different target-ion sources system
Surface ionization
Hot plasma
RILIS
Cold plasma
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ISOL targets

• Different target materials
• molten metals Ge, Sn, La, Pb, Bi, U,...
• solid metals Ti, Zr, Nb, Mo, Ta, W, Th,...
• carbides Al4C3, SiC, VC, ZrC, LaCx, ThCx,
  UCx,...
• oxides MgO, Al2O3, CaO, TiOx, ZrO2, CeOx,
  ThO2,...
• others graphite, borides, silicides, sulfides,
  zeolithes,...

• Target dimensions
• target container 20 cm long, 2 cm diameter
• target thickness 2200 g/cm2, 10100 of bulk
  density
• micro-dimensions of foils, fibers or pressed
  powder 130 mm

U. Köster for the ISOLDE Collaboration,
Radiochimica Acta 89 (2001) 749.

• More than 1100 isotopes and 300 isomers produced
  so far,
• for more than 70 different elements
• Secondary yields depends on several parameters
  effusion, diffusion times, surface adsorption
  properties

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The ISOLDE database

• Production mode proton pulses (3.1013 per pulse
  during 2 ms, 1.4 GeV) from PSB on a target/ n
  converter
• All measured data since 1993 are stored as Excel
  sheets
• SC yields are typically good-day-yields
• The new ISOLDE web database PSB Yields is quite
  incomplete. Concentrated on new elements

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The Web SC database
Neutron rich only Neutron deficient only
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SC-Yields estimate

• Proton beam intensities and energy 0.6 GeV
• CW beam. Straightforward analysis no time
  dependence as soon as the equilibrium state has
  been reached
• only best results taken into account.
  Performances can change with time and target-ion
  source setup.

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The PSB yields database
Only the most interesting yields are on-line
available! Some data 1) analyzed but not
published 2) not yet analyzed
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The PSB yields database
Real status, from Ulli Koester
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PSB-Yields estimate

• Fit of the yield release curves for the isotopes
  of one element
• Different conditions target matrix, T, ion
  source, ageing
• Some traps decay filiations the mother
  nuclides remains (partly) in the matrix
• Cumulative/ independent cross section
• A quite careful analysis is required

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Release profile ISOLDE
t0 production of radioisotopes by 2 ms short
proton pulse
80Rb release
80Rb release
logarithmic
linear
Release Diffusion Desorption
Effusion Release time profile is measured to
characterize the performance of a target and ion
source unit.
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Empiric release formula
80Rb release
80Rb release
Empiric 4-parameter formula
F(t) N (1-exp(-t/trise)) (a exp(-t/tfast)
(1-a) exp(-t/tslow))
J. Lettry et al., Nucl. Instr. Meth. B126 (1997)
130.
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Analytical release model
J.R.J. Bennett et al., Nucl. Instr. Meth. B126
(1997) 117. Nucl. Instr. Meth. B204 (2003) 211.

• Analytical model difficult to extend to
• more complicated target geometries
• effusion of ions influenced by electric fields
• pulsed driver beam gt 1 GW/cm2 during 2 ms ?
  thermal cycling of target, radiation enhanced
  diffusion,...

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Monte Carlo release models
C.J. Densham et al., Nucl.
Instr. Meth. B126 (1997) 154. B. Mustapha and
J.A. Nolen, Nucl. Instr. Meth. B204 (2003)
286. Mario Santana-Leitner, PhD, 2005
(http//www.ganil.fr/eurisol/ )

• Monte Carlo program adaptable to all target and
  ion source geometries including various physical
  processes, but
• difficult to deduce diffusion and desorption
  data from direct fit
• complete on-line test is an expensive method to
  test new materials

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Release delays
The required data are measured by TARGISOL
http//www.targisol.csic.es
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Schedule and Manpower

• Manpower situation
• - 1 EURISOL staff position in May, June -
  partial time
• - Lukic Strahinja, Post Doc, GSI, in next summer
• - summer student July August 2005
• - Ulli Köster supervising/providing support
• Preliminary schedule
• - Summer 2005 evaluated yields as .xls
• - End 2005 newly measured and evaluated yields
  (during 2005)

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• Special thanks to Ulli for the support and
  information concerning this presentation
• Thank you for your attention