Operation of accelerators at KEK
e-/e+ injector linac

Masanori SatohHigh Energy Accelerator Organization (KEK), Accelerator Lab. Div. V

Masanori Satoh (KEK)

WAO2023, Sept. 2023

1

KEK (since 1971)
Number of Staff Members ～ 700
Number of users ～ 46,000
Japan(A) KEK Tsukuba campus(Lepton accelerator complex)(B) KEK Tokai campus(J-PARC)
60 km

65 km
•
•
•
•
•
•

SuperKEKB
Photon factory (PF, PF-AR)
Injector linac
Accelerator Test Facility(ATF)
Compact ERL (cERL)Superconducting Test
Facility (STF)

KEKB/Belle experiment contributes
to Nobel Prize in Physics 2008!!!

60 km
45 km

HanedaAirport
WAO2023, Sept. 2023

NaritaAirport

J-PARC/T2K experiment contributes
to Nobel Prize in Physics 2015!!!
2Lepton accelerator complex in Tsukuba campus- simultaneous top-up since 2019 • Complex operation has been
conducted with the high-performanceaccelerator control systems.
e+

HER : e7 GeV

e-LER : e+4 GeV

SuperKEKB

Circumference : 3 km
STF

Injector LINAC(600 m, 50 Hz)

PF-AR: 6.5 GeV

e+ Damping Ring
PF: 2.5 GeV
WAO2023, Sept. 2023Stored current (red lines) (24 hours)

3Linac local control room
• Twenty 27-inch LCD and six 55-inch LCD for linac operation• Large LCD show alarm status, interlock status, and operation status• Monitor size is gradually improved: 15-inch -> 18-inch -> 21-inch -> 27-inch

CSS
alarmOperation
StatusInterlock

Softwaredevelopment

Monitoring camera
for power supply

Softwaredevelopment

Linac beam operation
Masanori Satoh (KEK)

WAO2023, Sept. 2023

4

Central control room

SuperKEKB MR

PF-AR
Linace+ DR

Belle2

SuperKEKB RF

Masanori Satoh (KEK)

WAO2023, Sept. 2023

5

# of operators for accelerator operation• A three shift operation, one or two operators and one safety shift (KEK staff) are assigned ineach shift.
• In addition, some operators are also assigned to the maintenance work in weekday dayshift.
• prepare and/or fix spare power supply, software development, assist R&D work

Accelerator(# of operators in total)

Linac(12)SuperKEKB/PF-AR
(12)

PF(7)

Masanori Satoh (KEK)

Morning shift(0:00 – 9:00)

Day shift(9:00 – 17:00)

Evening shift(17:00 – 0:00)

22

2

2

2

2

1

1

1

WAO2023, Sept. 2023

6

Contact book for troubleshooting• Linac operator can fix most troubles.
• Safety shift staff call expert staff when serious trouble occurs.
• Contact book is prepared for each group and device.
Device name

Person in charge
RF group
contact bookMasanori Satoh (KEK)

WAO2023, Sept. 2023

7

Operation panel• In the beginning of KEKB project, all panels were developed with Tcl/Tk and in-house backend• Currently, most of operation panels are implemented with Python (Tkinter or Qt) and EPICS• Many feedback software (beam orbit, RF phase, beam energy, …)Interlock, beam gate status panel

Linac parameter management panel

Beam repetition management panel

Magnet parameter management panel
Masanori SatohBeam(KEK) orbit panel

WAO2023, Sept. 2023

8

Electrical operation logbook•••••

Web-based e-Log (in-house)
Angular, PHP, PostgreSQL
For each shift, it includes operator name, operation outline, trouble, schedule, ……
Image file is available.
Many information can be automatically updated in real time.
• e.g.) Beam on/off status, high voltage setting, beam gate, beam repetition, ……

List of operators and shift staff
Operation outline

Detail information of shift
9TroublesWAO2023,
Sept. 2023

Machine learning for automatic beam tuning• Auto tuning with Bayesian Optimization has been tested since Oct. 2022. (T. Natsui, G. Mitsuka)• Implementation was done by using GPyOpt and PySimpleGUI.
• To increase e+ yield and transmission efficiency with 16 parameters (pulsed steering, RF phase)• Expand auto-tuning to two bunch tuning, dispersion correction, injection tuning, and more(*) more details will be given by Miho Shimada in machine learning session.
After tuning

Before tuning
x (mm)y (mm)
I (nC)
e- beamAutomatic beam tuning panel
Masanori Satoh (KEK)e+ beame+ bunch charge improvement
T. Natsui
WAO2023, Sept. 2023

10

Summary・At the KEK e-/e+ injector linac, simultaneous top up injection operation of 5 rings(SuperKEKB HER/LER/PDR, PF, PF-AR) has successfully established.
• Pulse to pulse beam control based on the event based timing system, low level rfphase control, pulsed magnet (Quad, Steering, Bend)• 50 Hz monitoring (BPM, rf, pulsed magnet PS) and analysis tools• Many People’s Continuous Contributions and Efforts over 15 years• Issues and Future improvements• Training cost of operator is increasing (complex operation scheme, large # of OPI)
• Expand AI-based auto-tuning to reduce the load of operator

Masanori Satoh (KEK)

WAO2023, Sept. 2023

11

Thank you for your attention!

Masanori Satoh (KEK)

WAO2023, Sept. 202312