The ISOLDE yield database Measured secondary beams intensities at ISOLDE Pierre Delahaye for the...
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Transcript of The ISOLDE yield database Measured secondary beams intensities at ISOLDE Pierre Delahaye for the...
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
Different target-ion sources system
Surface ionization
Hot plasma RILISCold plasma
ISOL targets• Different target materials1. molten metals: Ge, Sn, La, Pb, Bi, U,... 2. solid metals: Ti, Zr, Nb, Mo, Ta, W, Th,...3. carbides: Al4C3, SiC, VC, ZrC, LaCx, ThCx, UCx,...4. oxides: MgO, Al2O3, CaO, TiOx, ZrO2, CeOx, ThO2,...5. others: graphite, borides, silicides, sulfides, zeolithes,...
• Target dimensions:target container: 20 cm long, 2 cm diametertarget thickness 2—200 g/cm2, 10—100% of bulk densitymicro-dimensions of foils, fibers or pressed powder: 1—30 m
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…
The ISOLDE database
• Production mode: proton pulses (~3.1013 per pulse during 2 s, 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
The Web SC database
Neutron rich onlyNeutron deficient only
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.
The PSB yields database
Only the most interesting yields are on-line available! Some data 1) analyzed but not published 2) not yet analyzed
The PSB yields database
Real status, from Ulli Koester
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
Release profile ISOLDE
80Rb release80Rb release
Release = Diffusion + Desorption + Effusion
Release time profile is measured to characterize the performance of a target and ion source unit.
t=0: production of radioisotopes by 2 s short proton pulse
logarithmic linear
Empiric release formula
F(t) = N · (1-exp(-t/trise)) · ( · exp(-t/tfast) + (1-) · exp(-t/tslow))
80Rb release 80Rb release
Empiric 4-parameter formula:
J. Lettry et al., Nucl. Instr. Meth. B126 (1997) 130.
Analytical release model
Analytical model difficult to extend to:
• more complicated target geometries
• effusion of ions influenced by electric fields
• pulsed driver beam: > 1 GW/cm2 during 2 s thermal cycling of target, radiation enhanced diffusion,...
J.R.J. Bennett et al., Nucl. Instr. Meth. B126 (1997) 117. Nucl. Instr. Meth. B204 (2003) 211.
Monte Carlo release models
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
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/ )
Release delays
The required data are measured by TARGISOL: http://www.targisol.csic.es
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)
• Special thanks to Ulli for the support and information concerning this presentation
• Thank you for your attention