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University of Birmingham
MC40 Cyclotron
David Parker
University of Birmingham
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• History
• Uses
• Problems
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History of accelerators at Birmingham
• 60” Nuffield cyclotron (1948-1999) 10MeV p, 40MeV
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History of accelerators at Birmingham
• 60” Nuffield cyclotron (1948-1999) 10MeV p, 40MeV
• Radial Ridge Cyclotron (1960-2002) (axially injected polarised
beams) 12MeV d, 24 MeV , 33MeV 3He
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History of accelerators at Birmingham
• 60” Nuffield cyclotron (1948-1999) 10MeV p, 40MeV
• Radial Ridge Cyclotron (1960-2002) (axially injected polarised
beams) 12MeV d, 24 MeV , 33MeV 3He
• 1GeV proton synchrotron
(1953-1967)
(overtaken during construction by Brookhaven Cosmotron)
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History of accelerators at Birmingham
• 60” Nuffield cyclotron (1948-1999) 10MeV p, 40MeV
• Radial Ridge Cyclotron (1960-2002) (axially injected polarised
beams) 12MeV d, 24 MeV , 33MeV 3He
• 1GeV Proton synchrotron (1953-1967)
• RDI 3MV Dynamitron (1970 - 3MeV p on Li for BNCT
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Lifting
PROBLEM!
The MC40 cyclotron is the third cyclotron to be operated at the
University of Birmingham
In 2002-2004 transferred from Minneapolis
to Birmingham
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In 2005 we added a 12-way switching magnet (blue) [ex
Vivitron]
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One beam line ran into adjacent room (past Dynamitron
accelerator)
and was used for studying radiation effects (e.g. space
electronics)
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More recently, we were asked to provide high dose-rate damage
studies
(LHC ATLAS group and metallurgy) so extended a second beam-line
into a
specially shielded area.
ISOTOPE
PRODUCTION
NUCLEAR PHYSICS AND
LOW DOSE RADIATION
EFFECTS
HIGH DOSE
DAMAGE STUDIES
TLA
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In 2009 Birmingham acquired most parts from the
decommissioned Hammersmith MC40
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p 11-39 MeV and 3-9 MeV (N=2)
d 5.5-19.5 MeV
11-39 MeV 3He 33-54 MeV and < 27 MeV
Also 46 MeV 14N4+ and 70 MeV 14N5+ for nuclear physics
Beams available (hot filament ion source)
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Cyclotron is used for
• Producing positron emitting nuclides for Engineering PET [NOT
FDG]
• Producing 81Rb for 81mKr generators
• Thin Layer Activation
• Other isotope production:
• 69Ge for labelling oil
• 62Zn, 64Cu supplied to St Thomas’ Hospital London
• Various irradiations for NPL
• Radiation effects studies:
• Radiobiology + dosimetry (proton imaging)
• Space electronics etc
• ATLAS components
• Metallurgy of nuclear materials
• Nuclear physics (student projects)
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Positron emission particle tracking (PEPT) Label a single
particle (grain of sand, etc) with positron-emitter
(usually 18F from 3He on natural oxygen) and track it as it
moves inside equipment
JAM02.A17
Ra dial Posit ion (mm)
Ax
ial
Po
siti
on
(m
m)
0 40 80 120 160 200190
230
270
310
350
390
44-49/10000
40-44/10000
35-40/10000
31-35/10000
26-31/10000
22-26/10000
17-22/10000
13-17/10000
8-13/10000
4-8/10000
0-4/10000
400mm/sec Vx
400mm/sec Vr
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81Rb production
Using the technique developed at MRC Cyclotron Unit
(Hammersmith):
Irradiate target containing 82Kr gas (6 bar pressure) with 29
MeV protons (30 A)
81Rb is produced and deposits on walls of target
At end of irradiation, recover 82Kr gas cryostatically
Then elute 81Rb from target: 3 x 40ml transferred to dispensing
room.
Finally evacuate target ready for reuse.
Currently making approx 65 generators per week – fairly
stable
Entire procedure is controlled by Beckhoff PLC
Same PLC has gradually been extended to control cyclotron
interlocks etc
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Thin Layer Activation
Using p, d and 3He
3He is used for activating carbon (DLC)
12C ( 3He, 2 ) 7Be
Peak cross-section ~ 55 mb (~ 20 MeV)
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Modifications to cyclotron systems
Helium-3 recovery system (Hammersmith) added 2009
Grid power supplies replaced by Glassman units (Hammersmith)
Arc power supply replaced by new Glassman unit (allows 3A
arc)
Hitachi PLC system replaced by Beckhoff PLC
Currently replacing Helium-3 PLC with Beckhoff
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81Rb Production statistics
Started 81Rb production in March 2006
5 evenings per week, 50 weeks per year
To end of 2011, attempted production on 1430 days,
of which 1404 were successful (98% success rate)
Unfortunately during 2012 success rate was only 90% due to a
series of
unrelated problems
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Recent faults
Chiller failed
Mains supply to University lost
RF fault – blew APS HV fuse every time we introduced drive
– eventually traced to coupling capacitor
(but first replaced dee stem insulator)
RF fault – dee voltage control strange
– bleed capacitors blown and took RDET card with them
Extraction poor – magnetic channel had shifted slightly
RF tuning problem – pickup from faulty Harmonic supply!
Previous repeated faults
MCPS will only regulate over part of range – transistor at top
of bank failed
Water pipes !!!
