Salah Chaurize August 21 2013 Notching History Notching is controlled removal of selected proton bunches to facilitate a gap in the beam This gap allows the Booster extraction kickers magnetic fields to reach full value to allow extraction of the remaining bunches ID: 816659
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Slide1
Booster Beam Notching PMG Meeting
Salah Chaurize
August 21, 2013
Slide2Notching HistoryNotching is controlled removal of selected proton bunches to facilitate a gap in the beam.This gap allows the Booster
extraction kickers magnetic fields to reach full value to allow extraction of the remaining bunches.Without the gap or “notch” in the beam, the extraction kickers would displace these bunches in a non-controlled fashion causing losses in the extraction regionIn the past “notching” was less critical due to lower beam intensities and lower beam duty cycles. Losses were tolerable.
Slide3Longitudinal distribution of
3 removing (red),
circulating (green)
and
survival at notching (blue)
bunches, and long (1.08m) and short (0.54m) notchers waveform at Long-13, and 1.08-m notcher waveform for Long-05 straight section.
December, 2011 A.Drozhdin
Slide4The Notch/Gap
3 Bucket Notch Width
non-cogged Cycle Notch @ 400MeVCogged Cycle Notch
@ ~700MeV
Extraction Loss
Gap
Slide5Booster Kicker Notching PlansPhase ICreate a Horizontal Notch scheme to deposit beam at L13 using existing Notching magnet systems.
Reduce losses to sensitive locations such as gradient magnets and RF cavities.Phase I is complete.Phase IIImprove notch kicker rise time to allow cleaner gap clearing and emmittance
growth of bunches adjacent to the cleared bunches.Build new short kickers and fast pulser to drive faster notch producing system.Magnets building in progress. Kicker power system building underway. Phase II is in progress.
Slide6Notching Pre-Shutdown 2012
A 3 bucket gap is created using two kickers located at Long 5 and Long 12Notcher – A High Voltage(55kV) Kicker at Long 5Noker - Lower Voltage Kicker (20-40 kV) at Long 12Used to clean out remnant n
otched beam in bucketsAt ~700 MeV due to Cogging operations.Beam is kicked vertically into Gradient Magnet dipoles at L5 and L12. Some notched beam reaches the collimator region at Long 6 and beam pipe mask at Long 13. This is not optimal Non-cogged notched cycles occurs at ~400 MeV.Cogged notch cycles occurs at ~700 MeV.
Slide7Notching Magnets at Long 5 and Long 12 Pre-Shutdown 2012
Notcher
Hor.
Pinger
De-commissioned
Horz. PingerVer. PingerNokerMKS04Beam directionL12 Pre-2012 Shutdown
L5 Pre-2012 ShutdownBeam direction
Slide8December, 2011 I.Tropin
Residual dose profiles, vertical cross section (30 days irradiation/1day cooling,
mSv
/
hr
).
Vertical
notcher
Notching at Long 5 Pre-shutdown
Slide9Booster Kicker Notching PlansPhase ICreate a dedicated region to deposited 3 bunches of beam to produce a extraction kicker rise time gap.
Use current CX1168 thyratrons and PS systems to drive 3 kickers that kick Horizontally rather than vertically. We implemented a three kicker system to go into Long 12 and Long 13 as the absorber regions.
This first phase is completed. Notched beam has been achieved with this new horizontal configuration. Further orbit tuning and timing adjustments will continue as we commission MI beam.
Slide10Horizontal position of 3-σ circulating beam and removed beam at notching for magnetic field of
two horizontal notchers of B=67Gauss at 400 MeV (top)
and
two notchers of B=72.5Gauss plus one notcher of B=35.2Gauss at 700 MeV (bottom).
Three horizontal notchers at Booster Long-12
with beam dump at Long-13 straight section.
August, 2011
A.Drozhdin
Slide11Three
notchers
with field of B=62 Gauss.
The aperture of Short-12 straight section should be increased to R>86mm to eliminate losses.
This can be done by
displacement
of R66.5mm
aperture
(without BPM) by dX=20 mm. [46.5-86.5]mm
Y
Short-12
dX=70mm
400MeV
Circulating beam
3
σ
(
ε
=18
π
)
Dump-13
X
Red – 30
π
, green - 18
π
August, 2011
A.Drozhdin
Slide12Long-13:
Loss Simulations
December, 2011 I.Tropin
Side view
Top view
Slide13Slide14Reason to redesign S12 Spool piece
Need to kick beam horizontally at L12 to create a notch in the beam.Horizontal aperture is current 4.5 in at S12
Maximum aperture through Booster Short Corrector is about 5 in. Current aperture restriction at S12 is BPM plates and upstream and down stream bellows which are all 4.5in.
Slide15Reason to redesign S12 Spool piece
New Extra Wide aperture BPM will give us 5 in aperture with new spool.New spool would use original spool design without the standard BPM components inside and larger aperture spool bellows
Slide16Extra Wide Aperture BPM
Slide17Short 12 Corrector Spool Upgrade
New 5” Aperture Spool
Standard aperture 4.5 Inch
New Extra wide BPMStandard BPM inside
Slide18Notching Post ShutdownPhase I
A 3 bucket gap is created using three Long kickers located at Long 12
3 Notcher – High Voltage(46-54kV) Kickers at Long 12Notcher PS converted to NOKA PSNoker PS converted to NOKB PSBuilt/Commissioned new NOKC PS mostly with parts on hand.Beam is kicked Horizontally into new absorber at Long 13 Extra Wide Aperture BPM and Short Corrector Spool needed to allow kicked beam horizontal displacement before reaching absorber.
Non-cogged notched cycles occurs at ~400 MeV.(unchanged)Cogged notch cycles occurs at ~700 MeV.(Unchanged)
Slide19L12
Post Shutdown
NOKCMKS04
NOKBNOKA
Slide2012-13 sections of Booster tunnel.
Long-13
Long-12
Kick
at L12 to Aisle.
Slide21Long 13 Notched beam absorber
Beam direction
Before
After
Slide22Long 13
Beam direction
Slide23Long 13 Actual new absorber
Slide24Current Configuration
In East Gallery
NOKA
NOKB
NOKC
Slide25Current Configuration In East Gallery
NIM Gate Modules Altera Based
CAMAC Controls and Ramp Cards
LeCroy
Delay modules & CAMAC Trigger
Slide26Notching turned On and Off
Extraction loss monitor
Notching off
Notching on
Beam Charge
Slide27400 MeV Notched beamAbsorber in operational position
Slide28400 MeV Notched beam
Absorber Retracted
Slide29700 MeV Notched beam
Currently
Slide30Preliminary Results and Commissioning
Slide31Phase IICurrent BKED (Long) design kicker have a rise time of about 35ns Short BKEF kicker modules are about half as long. They will produce a rise time of about 25ns.
The voltage propagation time through the short kicker is cut from 20ns to 10ns due to half length.Two short kickers will rise faster with appropriate pulser to reach a desired flatop value.
We will use a ANU style pulser using a CX2610 hydrogen thyratron rather than the existing CX1168 tube. This new pulser we gain us about 8-15ns of rise time.One Pulser can drive 4 magnets, possibly 6.
Slide32Phase IIC. Jensen and J. Biggs along with EE support group is currently working on acquiring and building an ANU style pulser
. Pulser components will be built through out 2013.We hope to have one pulser operating in a test configuration by the end of 2013.We will try to convert one long kicker to a pair of 2 short kickers as soon as feasible(2013/14)
Slide33C. Jensen
Slide34New Short kicker PS RackFront/Back viewEE Support currently building System
Slide35New Pulser for Short BKEE/BKEF Kicker Example(ANU Pulser Test Unit)
Slide361Long Kicker BKED Series
2 Short Kicker BKEE Series
Slide37ConclusionHorizontal Beam notching is working.
Estimated notched beam power max is about 250watts which is half the budgeted power loss for Booster. The New L13 notched beam Absorber gives us 50% more head room on lost beam power. This helps towards future 15Hz. Operations
Phase II should give us further improvements towards 15Hz. Operations.
Slide38Thanks to:-L13 Notched Beam Absorber Assembly-
PPD Experiment Fabrication- L13 Absorber Build and AssemblyD.Erickson, J. Judd, W. Blaszynski, W. Gatfield
V. Sidorov - L13 Absorber Mechanical DesignAPC Energy Deposition Simulations by- N.Mokhov, I. Tropin, S.Drozhdin M. Coburn L13 Absorber Motion Controls
-L12, S12, L13 Upgrade Support-Mechanical Support/ Instrumentation Groups – L13/S12 BPM and CorrectorR. Reily, B. Ogert, J. Kubinski
, J.
Briney
,
D. Wallace, J. FitzgeraldControls Group CAMAC modulesBooster Techs - Power supply and load reconfiguration New timing module build and support electronics R. Mraz, T. Boes, D. DickOperations - Database work , O. Marshall, R. JonesAMG-L12, S12,L13 alignmentRadiation Safety – Joel FulghamConsultation – J. Lackey, B. PellicoMachine Shop, Welding ShopMany More I missed
Slide39END
Slide40Reserve Slides
Slide41Looking upstream towards L13
Before
After
Slide42Short Kicker/ Power Supply EffortPurpose of short kicker is to reduce kicker magnet rise/fill time.We can improve rise time of magnet field from current ~32nsec to about 25nsec.
This will improve beam bunch removal with reduced disturbance of bunches intended for extraction.
Slide43New Short Kicker Pulser Control and PS racks location. East Booster Gallery
Slide44BKEE02(Short Module)Voltage ~40kV
Slide45BKED012(Long Module)Voltage ~40kV
Slide46BKEE001
Short
42KV
NokerBKED012Long42KV
Noker
Channel 1 V in
Channel 2
VoutChannel 3 Load I
Slide47Preliminary finding is a 8-15 ns difference between
ANU
pulser and Operational Booster pulser(Slower)Testing by Jensen, Chaurize