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Ion source related development work at JYFL. University of Jyväskylä, Department of Physics. Hannu Koivisto. Juha Ärje. Olli Tarvainen. Pekka Suominen. Pentti Frondelius. Markus Savonen. Tommi Ropponen. Tarmo Koponen. Petteri Lappalainen. Plasma potential measurements
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Ion source related development work at JYFL University of Jyväskylä, Department of Physics Hannu Koivisto Juha Ärje Olli Tarvainen Pekka Suominen Pentti Frondelius Markus Savonen Tommi Ropponen Tarmo Koponen Petteri Lappalainen ECPM, Nice
Plasma potential measurements ISIBHI (FP6-project for ECRIS) Evaporation ovens MMPS (Modified MultiPole Structure) Contents ECPM, Nice
(on HV rack) Voltage supply 0 – 100 V Mesh at high voltage (Vsource + Vadjustable) Ion beam Bending magnet Grounded front plate including the collimator Back plate Plasma potential measurement ECPM, Nice
Plasma potential definition ECPM, Nice
One scan takes about 30 seconds Plasma potential vs temperature High plasma potential -> No temperature effect! plasma potential same for all charge states ECPM, Nice
Plasma potential vs temperature Low plasma potential -> temperature effect dominates Linear fit cannot be used for low charges Most reliable plasma potential value is obtained with high charge states! ECPM, Nice
Simulated decay curves Code includes different input values: - plasma potential profile - distribution of ions - temperature of ions - mass and charge state Exact overlapping of measured and simulated curves only with certain input parameters -> plasma potential and temperature are obtained ECPM, Nice
Ion temperature ECPM, Nice
Plasma potential vs emittance ECPM, Nice
Development work for ISIBHIISIBHI-project leader: G. Ciavola (INFN-LNS) ISIBHI? ECPM, Nice
EURONS / JRA-07 / ISIBHI Ion Sources for Intense Beams of Heavy Ions • Partners: 10 laboratories • INFN-LNL : SPES project (q/A) = (1/3) • INFN-LNS : heavy ion beams up to U60+ between .2 and 2 eµA (cw mode) • 5 pµA of light ions up to Ar16+ (hopefully Ca18+)for the EXCYT project • GSI :ions of (A/q) = 1 to 8.5 are needed, dc mode : Xe20+~ 1 emA; pulsed mode : 6 mA of U28+, from 2.5 to 5.0 keV/nucleon, emittance < 200 mm.mrad. • GANIL : LINAG Project (q/A) = (1/3) 1 emA 36Ar12+ cw mode, krypton beams • LPSC : design, construction and tests of Ion Sources and charge breeder (SPIRAL II, ISOLDE, TRIUMF….) • KVI: very high charge state for the superconducting cyclotron AGOR • JYFL Jyvaskyla : > 100 pnA for ions up to Uranium with a mass to charge ratio ~ 4.7 • TSL Uppsala: intense highly charged Xe, Bi, U beams for injection into cyclotron • CERN : 1 emA intermediate charges, 2.5 keV/nucl (long pulse mode: 200 µs) • 6 mA , 6 µs (short pulse mode) • NIPNE: ECR for ion-atom collision studies at different energies ECPM, Nice
A Multi-purpose totally Superconducting ECRIS (MS-ECRIS, inspired from the GyroSerse project), with an adjustable magnetic configuration : Bmax = 4 T; Brad = 2.7 T; large ECR zone, f = 28 GHz according to our scaling laws A more compact source, with a lower magnetic field and an higher power density (A-PHOENIX source) with a technology based on HTS coils and permanent magnets Bmax=3 T; Brad~ 1.7 T to 2.2 T GOALS To design, build and test prototypes of ECRIS with a magnetic field still never reached and frequency ≥ 28 GHz ECPM, Nice
SERSE MS-ECRIS f 18 GHz 28-37 GHz Bradial 1.55 T 2.7 T Binj 2.7 T 4.5 T Bext 1.6 T 3.2 T chamber 130 mm 180 mm L chamber 550 mm 650 mm cryostat 1000 mm 1200 mm L cryostat 1310 mm 1347 mm Au45+ Vextr 20-25 kV 40 to 60 kV LHe consumption ~4l/h 0 O8+ ~7 pA ~ 20 to 50 pA Ar12+ 15 pµA 100 pA ~1 pnA ~0.1 pA Xe20+ ---- ~50 pA Pb27+ ---- 40 pA Multipurpose Fully Superconducting Magnets adapted to all accelerators ECPM, Nice
Planning • Magnetic system and cryostat are expected for the spring 2007 • Mechanics will be available at GSI at beginning of 2007 • Microwave generator and ancillary equipment at same time • First beam July 2007 • Test with gaseous beams in DC mode: 2nd half 2007 • Test with metallic beams in DC mode: 1st half 2008 • Test in pulsed mode: 2nd half 2008 ECPM, Nice
Resistively heated oven Oven development work was needed for ISIBHI/EURONS Requirements: 1) operation at 2000˚C 2) duration of several days at 2000˚C with the MS-ECRIS 1) Modification of HTO and GSI standard ovens for MS-ECIRS 2) New development (this has been the focus point of our work) ECPM, Nice
Molybdenum crusible heated by radiation from tantalum foil Needs about 70 A / 8 V (560 W) to reach 2000°C Foil oven ECPM, Nice
Fully ”Homemade resonant circuit” >2000°C @ 400W Problems with reliability Inductively heated oven We were inspired by the results of P. Zavodszky PROBLEMS WITH THE FINAL SET UP IN THE ECRIS ECPM, Nice
1) 2 T -> inside iron B = 2 T -> Iron JYFL MMPS (Modified MultiPole Structure) High permeability material vs improvement of b-field 2) Bperbendicular between the boundary of two different media is continuous ECPM, Nice
MMPS-results: Will be tested with A-PHOENIX ECPM, Nice
”Homemade” integrating current measurement system Keithley 485 Picoammeter (noise) V=It/C New instrument Beam current measurement system www.phys.jyu.fi ion sources THANK YOU!! Earlier: laboratory ground Now: through PXI rack-mount ECPM, Nice