Synchronized Timing and Control System Constructionof SuperKEKB Positron Damping Ring
Hitoshi Sugimura, H. Kaji, Y. Ohnishi, K. Furukawa, F. Miyahara,
M. Satoh, T. Nakamura, S. Sasaki
KEK

Oct. 12, 2017

Hitoshi Sugimura (KEK)Timing System of SuperKEKB DR

Oct. 12, 2017

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Contents

1

SuperKEKB Project2

Event Timing System

3

Event Timing System at DR

4

Pre-trigger Timing

5

Conclusions

Hitoshi Sugimura (KEK)Timing System of SuperKEKB DR

Oct. 12, 20172 / 16

SuperKEKB ProjectContents

1

SuperKEKB Project2

Event Timing System

3

Event Timing System at DR

4

Pre-trigger Timing5Conclusions

Hitoshi Sugimura (KEK)Timing System of SuperKEKB DR

Oct. 12, 20173 / 16

SuperKEKB ProjectSuperKEKB Projecte + -e − collider, B-Factory
Aim at 40-times higher Luminosity than previous KEKB project2 × 1034 cm−2 s−1 (KEKB) → 8 × 1035 cm−2 s−1 (SuperKEKB)

Twice larger storage beam → Higher beam current at Linac
20-times higher collision rate with nano-beam scheme

Hitoshi Sugimura (KEK)Timing System of SuperKEKB DR

Oct. 12, 20174 / 16

SuperKEKB ProjectDamping Ring (DR)Emittance become down to 1/500 during damping time.
40 ms damping while linac operate at 50 Hz
Accomodate 2-bunches × 2-pulses
2-bunches in a pulse are separated by 96.3 ns (10.385 MHz)
Injection/extraction kickers rise/fall times are ∼ 100 ns
96ns

EnergyRepetition frequency
LengthRF frequency
Harmonic Number
Number of bunches
Bunch spacing

1.1
50
135.5
508.9
230
2
96

GeV
HzmMHzHitoshi Sugimura (KEK)Timing System of SuperKEKB DR>100ns>100ns96ns

ns

Oct. 12, 2017

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Event Timing System

Contents

1

SuperKEKB Project2

Event Timing System

3

Event Timing System at DR

4Pre-trigger Timing

5Conclusions

Hitoshi Sugimura (KEK)Timing System of SuperKEKB DR

Oct. 12, 20176 / 16

Event Timing System

Event Timing System for Simultaneous Top-up Injection
Fast, global and synchronous controls
synchronized with 114 MHz RF clock and 16 bit/clock event/datatransfer

MRF’s series Event Generator and Receivers
VME-EVG-230 / VME-EVR-230-RF / PXI-EVR-300

System communicate VME64x and PCIe (VxWorks v6.8 andWindows)
EPICS R3.14.12 with mrfioc2 (device support)
Event Generator.......

.......

e − GunPF
e + target

SuperKEKB:HER,LER
PF-AR

Hitoshi Sugimura (KEK)Timing System of SuperKEKB DR

Oct. 12, 20177 / 16

Event Timing System

Injection and extraction timing at DR
LINAC
2856 MHzDR(230Bkt)
508.9 MHz

LINAC
2856 MHzMR(5120Bkt)
508.9 MHz

Two timings (injection and extraction at DR) are needed
Common frequency between 2856 MHz and 508.9 MHz is
10.38 MHz (96 ns, 49 buckets duration)
Chance of injection timing turns up once per 96ns (49buckets).

Need to consider bucket select combination each DR and MR
buckets.
The number of combination is 5120 × 23 (least common
multiple of DR and MR)Hitoshi Sugimura (KEK)Timing System of SuperKEKB DR

Oct. 12, 20178 / 16Event Timing System

Master Timing System
Master Timing System
consists of 1-upper EVG,
1-upper EVR and 2-lower
EVGs in 1-IOC.
It delivers dozens kinds oftiming (BPM, Kicker,Septum ...).

LINAC
2856 MHz

Hitoshi Sugimura (KEK)

EVG
Event

EVR
TTL

TTL

EVG

EVG

DR(230Bkt)
508.9 MHz

LINAC
2856 MHz

Timing System of SuperKEKB DR

Upper EVG calculates
which bucket isinjected/extracted(bucket selection).
Lower each EVGs
delay timing according
to bucket-ID.

MR(5120Bkt)
508.9 MHzOct. 12, 20179 / 16

Event Timing System at DRContents

1

SuperKEKB Project2

Event Timing System

3

Event Timing System at DR

4

Pre-trigger Timing

5

Conclusions

Hitoshi Sugimura (KEK)Timing System of SuperKEKB DR

Oct. 12, 201710 / 16

Event Timing System at DR

Timing Constraints at DR

Kicker Timing
Injection/extraction (especially extraction) kicker timing is mostimportant to have effect of beam jitter.
Injection/extraction kicker need charging trigger ∼ 15 ms before firing.
We call “pre-trigger”.

Pulse trains should be provided for BPM
at revolution frequency (508.9 MHz/230)
synchronized to one of the beam bunces in DR

dispersion measurement508.9 MHz ± 50 kHz
should be disconnected from other clocks

Hitoshi Sugimura (KEK)Timing System of SuperKEKB DR

Oct. 12, 201711 / 16

Event Timing System at DR

Event Timing System at DR
Master Timing System

DR Timing System
114 MHz RF

PF
PF-AR

EVG

erg
pre-trig

114 MHz RF

monitorrev/49/23
EVG

Kicker
Septum

EVR

DR RF

EVR
114 MHz RF
PF-AR
PF

EVG

DelayLogic
monitorerg
pre-trig
EVR

Kicker
Septummonitor(DR toLinac)

Injection and extraction timing event is sent to each EVRs.
EVR for injection and extraction timing distribute main timing andpre-trigger timing.
The pre-trigger timing is originally generated EVR itself.
For dispersion measurement, valuable delay logic is added.
Hitoshi Sugimura (KEK)Timing System of SuperKEKB DR

Oct. 12, 201712 / 16

Pre-trigger Timing

Contents

1

SuperKEKB Project2

Event Timing System

3

Event Timing System at DR

4

Pre-trigger Timing

5Conclusions

Hitoshi Sugimura (KEK)Timing System of SuperKEKB DR

Oct. 12, 201713 / 16

Pre-trigger Timing

Event stream from EVG to EVR
Event is sent from EVG to EVR every 20 ms. Suppose to thinkabout DR injection timing at Shot#n.
Shot#n − 220ms

Shot#n − 120ms

Shot#nEVGt

EVRt

Hitoshi Sugimura (KEK)Timing System of SuperKEKB DR

Oct. 12, 201714 / 16

Pre-trigger Timing

Event stream from EVG to EVR
MR timing is sent after bucket selection delay “Dmain ”. “Dmain ”
would change shot by shot due to bucket selection.
Shot#n − 2

20ms

Shot#n − 120ms

Shot#nt

EVGt

EVR

MR Timing
Dmain [n − 2]

Hitoshi Sugimura (KEK)

Dmain [n − 1]

Timing System of SuperKEKB DR

Dmain [n]Oct. 12, 201714 / 16

Pre-trigger Timing

Event stream from EVG to EVR
Delay time for pre-trigger (Dpre ) is received by using “Data Buffer”
before Shot #n-1. Then, set Dpre .
20ms

Shot#n − 2

20ms

Shot#nt

Dpre setDpre set

Pre2

Pre2

EVR

Shot#n − 1

Dpre set

EVGt

pretriggate

MR Timing
Data Buffer
Dmain [n − 2]

Hitoshi Sugimura (KEK)

Dmain [n − 1]

Timing System of SuperKEKB DR

Dmain [n]Pre2 Event

Oct. 12, 201714 / 16

Pre-trigger Timing

Event stream from EVG to EVR
Pre-trigger timing is generated from MR timing.
Main trigger timing is generated from Linac timing with no delay.
20ms

Shot#n − 2t

Dpre set

Dpre

Shot#nDpre set

Pre2Pre2

EVR

20ms

Shot#n − 1

Dpre set

EVGt

pretriggate

MR Timing

15ms

Data Buffer
Dmain [n − 2]

Dmain [n − 1]

Dmain [n]Pre2 Event
Linac Timing(= DR Timing)
DR preTiming

The delay time (Dpre ) from MR timing is calculated as eq(1).
Dpre [n] = Dmain [n] − Dmain [n − 1] + 5ms(1)

In this system, timing jitter is measured with 30 ps jitter.
Hitoshi Sugimura (KEK)Timing System of SuperKEKB DR

Oct. 12, 201714 / 16

Conclusions

Contents

1

SuperKEKB Project2

Event Timing System

3

Event Timing System at DR

4

Pre-trigger Timing

5Conclusions

Hitoshi Sugimura (KEK)Timing System of SuperKEKB DR

Oct. 12, 201715 / 16

Conclusions

Summary

SuperKEKB project aims at 40 times higher luminosity than previous
KEKB project
Operation of damping ring will be started in this FY
Injector linac, damping ring, EPICS control system, event-based
synchronous system are beging constructed
Pre-trigger system was constructed with 30 ps timing jitter
Long stablity test will be started soon.

Hitoshi Sugimura (KEK)Timing System of SuperKEKB DR

Oct. 12, 201716 / 16