Transcript A_Herlert - ISOLDE

ISOLDE scientific coordinator’s report
ISCC meeting, February 4, 2010
A. Herlert, CERN PH-SME-IS
Running statistics 2009
Status of experiments
HV platform renovation
Status ISOLDE web page
ISOLDE schedule 2009 (Apr 20 - Nov 23)
Requested shifts:
• 662 in total
• 96 different beams
• 627 for 51 experiments
Scheduled shifts (~70%):
• 463 in total
• 62 different beams
• 437 for 39 experiments
REX-ISOLDE:
• 273 shifts requested
• 140 shifts scheduled
• 9 experiments (8 runs)
• additional WITCH runs
(need REXTRAP)
GPS
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HRS
ISCC February 4, 2010
ISOLDE beam time summary 2009
• ISOLDE delivered 350 RIB shifts
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•
288 (82.3%) for INTC experiments
62 (17.7%) other
• Standard target check + TISD + REX-MD
• Coordinators reserve: debugging, recovery, tests, LOIs
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•
A. Herlert
40 research projects (IS experiments) – 6 with no beam
2 LOIs
Integrated # protons
• 6.65E+19
• Running for 223 days
• More requests for GPS
ISCC February 4, 2010
RIB overview GPS/HRS 2009
PSB septum leak (no target change)
and PISOMOVE problem
on/off-time from
radiation monitors
Power cut and
severe vacuum
problems
LINAC2
vacuum
problem
HRS frontend
blocked
52% of possible
RIB shifts used
(1.57 shifts/day)
(55% in 2006
61% in 2007
56% in 2008)
223 days of on-line operation
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ISCC February 4, 2010
ISOLDE shift distribution 2009
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ISCC February 4, 2010
ISOLDE shift distribution 2000-2009
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ISCC February 4, 2010
Number of shifts
Shift distribution 1998-2009
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ISCC February 4, 2010
Key resources: targets 2009
• Actinide targets
• 218 shifts (out of 350) [62%]
• 12 new units + 2 old (one not used)
• In total 27 targets
• 23 new units
• 2 not used
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ISCC February 4, 2010
Key resources: RILIS 2009
• 155.5 total RIB shifts
• 152 shifts for INTC experiments
• ~2000 hours for online work
• includes setup, yield checks, etc.
• >2100 hours total running time (incl. off-line tests)
• 20 IS experiments (13 runs)
• Beams: Mn, Be, Ga, Ag,
Nd, Po, Mg, Sn,
Zn, Ni
(all with Nd:YAG)
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ISCC February 4, 2010
REX-ISOLDE 2002-2009
• 91 RIB shifts delivered to experiments
• + 5 RIB shifts for development
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ISCC February 4, 2010
New and closed experiments at
ISOLDE
Update November 2009 meeting
• 76 shifts out of 146 approved
• 4 new experiments IS495 - IS498
ISOLDE experiments to be closed
• IS410, IS420, IS438, IS461, and IS470
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ISCC February 4, 2010
Accelerator schedule 2010 (V1.3)
ISOLDE dates:
protons from PSB April 26
physics start ISOLDE April 29
protons stop November 22
(i.e. 29.5 weeks for physics
as compared with 31 weeks
in 2009)
Longer shutdown period
due to new HRS front-end
and new vacuum system
Several long periods of MD
partly with parasitic beam to
ISOLDE (not guaranteed)
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ISCC February 4, 2010
Follow up: floor space for experiments
MISTRAL
MINIBALL
ISOLTRAP
Em
Ch
WITCH
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b
ISCC February 4, 2010
Status of experiments - MISTRAL
• Clean-up ongoing
• RFQ buncher and cooler of
MISTRAL removed (shipped
to University Mainz)
• Removal of 22t magnet
planned in March 2010
(opening to hall extension
needs to be enlarged by
50cm – work to be done
in February 2010)
Oct 2009
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ISCC February 4, 2010
Status of experiments - ASPIC
• ISOLDE group owner of equipment
• LOI submitted and will be discussed at
February 2010 INTC meeting
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ISCC February 4, 2010
Status of experiments - HV Platform
• Can only be used for collections
Nov 2009
• Acceleration stage not functional
• Need new transformer?
• Check vacuum system
Renovation of
HV platform needed
Information collected
by Karl Johnston
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ISCC February 4, 2010
HV Platform – present location
Located in the middle of the hall, between CRIS and ISOLTRAP
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ISCC February 4, 2010
Collection
chamber
Status
• Platform consists of a (no-longer used) cryostat and a
small collection chamber
• Components on the platform are powered via an
external motor when whole system is under high voltage
• However, present setup not very user-friendly (vacuum,
general operation) - beam optics a problem
• Occupying large floor space, relative to use
• Safety report from 2009 not very positive
Cryostat
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External
motor
ISCC February 4, 2010
Some history
• The present platform was designed and constructed for a specific experiment (IS303).
• Originally mounted in ISOLDE-3
• Due to budget restrictions most of the components of the existing installation were taken
from equipment available at CERN.
• Only the driving motor for the power generator was obtained commercially.
Quoted performance parameters
High Voltage:
Design aim:
400 kV
Tube limitation:
500 kV
HV Generator:
300 kV
Resistor chain:
260 kV
Practical limit:
220 kV
3-Phase Power Generator:
7 kW
Optical links used: GPIB, ETHERNET, TTL pulses
Since 2007, HV power supply has been broken
Only collection point has been used (sparingly)
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ISCC February 4, 2010
Is there a need for a post-accelerated
(non-REX) beam?
YES: High Voltage platform for TISD
• (HIE)-ISOLDE offers the largest choice of ISOL beams; it should further
be extended.
• TISD can offer higher intensities for many exotic beams.
• The High Voltage platform (up to 260kV) is used to deduce release
properties of new targets with implanted long-lived radiotracers and offline gamma spectroscopy.
• Required for all release-type studies exploring new targets
Example: 17F at REX ISOLDE produced from
sub-mm SiC target for Astrophysics.
Production tests involved implantation depth
dependences for release properties
A. Herlert
ISCC February 4, 2010
Solid state Physics: maybe, but
probably not with current setup
Majority of current experiments do not require post-acceleration:
• Post-implantation, most experiments require annealing to repair
implantation damage. This diffuses ions further into the material (generally,
rare earths in Si an exception).
• For samples studied using optical spectroscopy (e.g. ZnO), too deep can
be a disadvantage as laser only absorbed within 100s of nms from surface.
• Recent experimental demands have been for beam retardation rather than
post-acceleration.
Where it could be useful:
• In principle, better focussing of the beam.
• Implantation into specific layer of multi-layered structure.
• For electrical measurements of semiconductors: implantation deeper
removes possible surface effects.
• b-NMR studies for solid state physics.
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ISCC February 4, 2010
Possible alternatives?
• Construct more user-friendly setup at one of the GPS collection points?
• New solid state physics BMBF proposal describes a new collection
chamber. Could, in principle, be modified to accommodate postacceleration.
• Smaller form factor, more standardized components…
• Older plans were drawn up to enhance existing setup by taking highly-charged
EBIS beams to reach higher energies…2 most realistic options were:
• e.g. after old ECR on GHM was mooted, but this opportunity has been
lost.
• Or to left of REX LINAC, area around ASPIC/TAGS, space and existing
installations a problem though.
In summary, HVP would be welcome for users – especially for
target development – but not sure if investing in current
setup is the best way to proceed
However, very important to retain collection point on HRS
A. Herlert
ISCC February 4, 2010
New location for HV platform ?
MISTRAL
MINIBALL
ISOLTRAP
Em
Ch
WITCH
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b
ISCC February 4, 2010
Status ISOLDE web page
New web page presently located at:
http://isolde.web.cern.ch/ISOLDE/isoldenewweb
Will be moved to new location next week
http://isolde.web.cern.ch/ISOLDE/
Many pages still not up to date
 Work in progress – Suggestions are appreciated
A. Herlert
ISCC February 4, 2010