Upload
alan-goodwin
View
226
Download
0
Tags:
Embed Size (px)
Citation preview
K.Furukawa, KEK, Nov.2015.Injector Linac Progress towards SuperKEKB
Progress of Injector Linac
Kazuro Furukawafor Injector Linac
1
K.Furukawa, KEK, Nov.2015.Injector Linac Progress towards SuperKEKB
40-times higher LuminosityTwice larger storage beam Higher beam
current at Linac20-times higher collision rate with nano-beam scheme
Low-emittance even at first turn Low-emittance beam from
Linac Shorter storage lifetime Higher Linac beam current
Linac challengesLow emittance e-with high-charge RF-gun
Low emittance e+with damping ring
Higher e+ beam currentwith new capture section
Emittance preservationwith precise beam control
4+1 ring simultaneous injection
Mission of electron/positron Injector in SuperKEKB
2
Linac Upgrade Overview
K.Furukawa, KEK, Nov.2015.Injector Linac Progress towards SuperKEKB
Required beam parameters
Stage KEKB Phase-I SuperKEKB
Item e+ e- e+ e- e+ e-
Energy 3.5 GeV 8.0 GeV 4.0 GeV 7.0 GeV 4.0 GeV 7.0 GeV
Bunch charge
Primary e-10nC
→ 1 nC
1 nC
Primary e- 4nC
→ 0.2 nC1 nC
Primary e-10nC
→ 4 nC
5 nC
Norm.Emittance (ge)(mrad)
2100 100 2400 150100/20
(Hor./Ver.)50/20
(Hor./Ver.)
Energy spread 0.125% 0.125% ±0.5% ±0.5% 0.1% 0.1%
Num. of Bunch / Pulse
2 2 2 2 2 2
Repetition rate 50 Hz 50 Hz 50 Hz
Simultaneous top-up injection
3 rings (KEKB e-/e+, PF)
No top-up4 rings
(SuperKEKB e-/e+, PF, PF-AR)
3
K.Furukawa, KEK, Nov.2015.Injector Linac Progress towards SuperKEKB
Linac Schedule Overview
4
RF-Gun e- beamcommissioningat A,B-sector
e- commiss.at A,B,J,C,1
e+ commiss.at 1,2 sector (FC, DCS, Qe- 50%)e- commiss.at 1,2,3,4,5 sector
non damped e+ commiss.at 1,2, 3,4,5 sectorse- commiss. at A→5 sectors
damped e+ commiss.at 1→5 Qe+ = 1~4nCe- commiss.at A→5 Qe- = 1~5nC
: Electron
: Positron
: Low current electron
2 nCPhase2
1 nCPhase1
Location↓
Time →
Phase1: high emittance beam for vacuum scrubPhase2,3: low emittance beam for collision
Schedule
Without Top-up
4 nCPhase3
Improved RF gun
Direct PF-AR BT
DR Commiss.
Step-by-stepLicenses
Low Emittance
Beams
4+1 RingInjections
K.Furukawa, KEK, Nov.2015.Injector Linac Progress towards SuperKEKB
JFY2010
Dismantle KEKB
KEKB operatio
n
SuperKEKB upgrade construction
SuperKEKB operation
Startup, conditionin
g, etc.
SuperKEKB master schedule
Belle II install,QCS install
Phase 1 Phase 2 、 3
・・・ ・・・
DR
Phase 1 commissioning : Basic machine tuning Low emittance beam tuning Vacuum scrabbing
Phase 2 commissioning : Squeezing beta at IP Beam collision tuning Start physics data taking
Phase 3 : Physics run with full Belle II with VXD
DR commissioning starts prior to Phase 2
JFY2011 JFY2012 JFY2013 JFY2014 JFY2015 JFY2016 JFY2017
Now (Nov, 2015)
About 10 years
Akai, Jun.2015.
5
K.Furukawa, KEK, Nov.2015.Injector Linac Progress towards SuperKEKB
Subjects to Consider
Too many subjects !
Phronesis needed (Greek: Practical wisdom, Ability to understand the Universal Truth)
6
K.Furukawa, KEK, Nov.2015.Injector Linac Progress towards SuperKEKB
Linac Upgrade Progress towards SuperKEKB (1)
High-charge low-emittance RF gun developmentQTWSC cavity and Ir5Ce
photo cathode developments
Positron generator commissioningGood agreement with
the simulation results
Precise alignment for emittance preservationRecovering after earthquakeReaching specification of 0.3mm
Utility upgrade during FY2014 for electricity (+1.5MW) and cooling water (+1400L/min)
7
Signal from primary electron
Signal from positron with opposite polarity
Ir5CeCathode
Quasi traveling wave side couple cavity
Positron generator
Linac Upgrade Overview
K.Furukawa, KEK, Nov.2015.Injector Linac Progress towards SuperKEKB
Linac Upgrade Progress towards SuperKEKB (2)
High power modulator upgrades Low-level RF controls/monitor
Pulse-to-pulse modulation (PPM) between 4+1 ringsMore spaces for increased number of devices
Beam instrumentationLarge/small aperture beam position monitors (BPM)Precise/fast and synchronized BPM readout systemWire scanners and beam loss monitorsStreak cameras (Deflectors, etc)
Event timing control systemCombination of MRF & SINAP modulesEssential for PPM operationPrecise timing & synchronized controlsBucket selection at DR and MR
8
SINAP event modules
Linac Upgrade Overview
Beam wire scanner
K.Furukawa, KEK, Nov.2015.Injector Linac Progress towards SuperKEKB
Recent Works
9
Recent works
Thermionic gunfor high-current beam
RF gunfor low-emittance
beam
Thermionic gunat #A1 region
Positron generatorat #15 region Iron shield
Positron generator complex
K.Furukawa, KEK, Nov.2015.Injector Linac Progress towards SuperKEKB
Preparation of Thermionic Gun Refurbished
Raise by 75cm not to conflict with straight RF-gun As well as angled RF-gun
~ Jun.2015. May serve
electrons in phase-Iprimary electron for positron generation in phase-II and later
10
Thermionic gun
RF gun
Thermionic Gun
K.Furukawa, KEK, Nov.2015.Injector Linac Progress towards SuperKEKB
Positron generation for SuperKEKB
New positron capture section after target with Flux concentrator (FC) and large-aperture S-band structure (LAS)Satellite bunch (beam loss) elimination with velocity bunchingPinhole (2mm) for passing electrons beside target (3.5mm)Recently, facing discharge difficulties at maximum field
Flux Concentrator
e+
5 nC injection e-
10 nCprimary e-
bridge coils
target
beamhole
pulsed ST
DC QM
pulsed QM
side view
spoiler
solenoid
LAS Accel. structure
11
positronproductionTarget
Flux Concentrator
BridgeCoils
primary e- beam
e+ beam
11
Positron Enhancement
K.Furukawa, KEK, Nov.2015.Injector Linac Progress towards SuperKEKB
Radiation protection licensesStep-by-step upgrade of beam limits
Final goal is 1250/625 nA before/after targetSame as KEKB
ApplicationsFall.2013. 10 nA at #28 dump, 1250 nA at #A2 dump
Spring 2014. New utility rooms, 50 nA at #61 straight dump
Jun.2015. 200 nA at #15 target
Early 2016.(?) 800 nA at #15 target, 625 nA at #61
Sometime 2016.(?) 1250 nA at #15 target
Shield, shield, shield, shield …
12
Schedule
K.Furukawa, KEK, Nov.2015.Injector Linac Progress towards SuperKEKB
Summary Steady progress towards first MR injection in FY2015
Finished earthquake disaster recovery in 2014
Will make step-by-step improvements up to Phase-III
Alignment: almost confident on the required precision (0.1-mm local, 0.3-mm global), need to maintain for longer term
Positron generator: another license test, need discharge analysis
Thermionic gun: re-commissioned, working
RF gun: following recommendations at review meetings
Need much more radiation shield
Will balance between final beam quality and progressive operation
Will select optimized route depending on available resources
With some Phronesis we may enjoy coming beam commissioning
13
Summary
K.Furukawa, KEK, Nov.2015.Injector Linac Progress towards SuperKEKB
SuperKEKB dual rings
Mt. Tsukuba
600m InjectorLinac
PF-AR
PF
14
Thank you
K.Furukawa, KEK, Nov.2015.Injector Linac Progress towards SuperKEKB 15