TRIAL LECTURES FOR ACCELERATOR OPERATORS IN SPRING-8
T. Ohshima†, SPring-8, Hyogo, JapanAbstract
In case of the SPring-8, accelerator operators are working
in three shifts of eight hours. They are making the scheduled
beam injection to the storage ring, routine measurements ofbeam parameters such as the COD, the betatron tunes, thebunch current of stored beam and so on. They are keeping
watch on operational state every time. In case of something
wrong, they will take measures to meet the situation.
Newcomer of operator works with an experienced one tolearn sequence of the beam injection, how to operate
Graphical User Interface and (GUI) so on. In addition, weorganise preliminary lectures on accelerator for operators.
Topics done in the lectures are RF system, vacuum system,magnet system, monitors, beam diagnostics, accelerator andbeamline control system etc. The contents of the lecture canbe seen through web browser again and again. It is usefulfor operators to understand the SPring-8 facility and detailsof their work because some of them are not familiar with theaccelerator field before being an operator of SPring-8.

1 INTRODUCTIONThe SPring-8 is one of synchrotron radiation (SR)facilities of third generation [1,2]. The nominal beam energy
is 8GeV, the maximum stored beam current of 100mA, thebeam emittance of 3.6nmrad. 62 beamlines can be installed
and now 44 beamlines are in operation. In these beam lines,
photon energy range up to 300keV can be used. Theinjectors consist of a 1 GeV linac and an 8 GeV booster
synchrotron. And also another storage ring named as New
SUBARU, which is steered by the Himeji Institute ofTechnology, is located on same campus as one of theSPring-8 accelerator complex. It is 1 - 1.5 GeV SR sourcewith the photon energy range from VUV to soft X-ray. The
operators in SPring-8 are working on these four accelerators.
The total operation time of the accelerator complex was,for example, 5543 hours in 2002. The user time was 3896
hours (about 70.8% of the operation time). There aresuccessive operation periods, which is called “cycle”. In
2002, the operation had been done with 11 cycles. The one
operation cycle lasts four or five weeks. The operation cycle
starts on Wednesday. After 12 hours for machine tuning and12 hours for beamline tuning, then user time starts. During
user time, there are beamline studies for 24 hrs and machinestudies for 48 hrs. Figure 1 shows the operational statistics.
The schedule is confirmed by the meeting before every_____________________† ohshima@spring8.or.jp

6000
5000
down
refilltuninguser

4000

time(hr)

3000
2000
100001997 1998 1999 2000 2001 2002

down

26

110

5788

87190

refill

50110

95

70

59

61

tuning 304 1458 1624 1815 1277 1395
906 2512 3275 3193 4033 3896
userFigure 1. The operational statistics since 1997.
operation cycle. The brief meeting is also held at 9:15 to
9:30 on Monday, Friday and the day at starting the beam
operation, beamline study and machine study. The members
attending to the meeting are staffs of linac, booster
synchrotron, storage ring, New SUBARU, beamline, safety,utilities and secretary.
In SPring-8, accelerator operators are working in three
shifts of eight hours, "shift I" starts from 9:00 to 17:00,"shift II" from 17:00 to 25:00 and "shift III" from 1:00 to9:00. Numbers of operators for each shift is four. Total
number of operators is twenty. The eldest operator has beenworking seven years in SPring-8. About seven persons were
exchanged from 1997 to now. In addition to operators, staff
members of the accelerator division take turns working for
shift leader. The shift leader is responsible for the matter
related to the accelerator operation. Numbers of shift leader
are one except for midnight shift of two.

2 DUTY OF OPERATORSThe important mission of the SPring-8 operation is todeliver stable SR to users with good quality. To accomplish
it, we take care to make an operation on schedule and quick
recovery in case of troubles such as beam abort.
As for regular beam injection to the storage ring, usual
procedure is as follows. Before injection they will makeannouncement such as "Beam injection will start on 10:00."
They will make adjustment of the beam current, fine-tuningof the beam energy of the injector. After injection, they

measure beam parameters of the storage ring such as COD,
betatron tunes. They will correct the COD if the distortion islarger than threshold level. And they will write down what
they did in a logbook. Figure 2 shows one scene in beam
injection procedure.

••
•
•
•
•
•

On insertion device ID23
Design concept of booster synchrotron
Control system of beamlines
Beamline for beam diagnostics
Radiation safety on operation of accelerator
RF gunSuper conducting wiggler
These lectures were held during machine maintenanceperiod. The accelerator staff who knew the part very wellmade the lecture for about one hour. Operators could ask
questions frankly to the staff during and after the lecture.
The lecture notes are uploaded to a server PC and anyone inthe SPring-8 site can browse them. It is important to givelectures repeatedly. So we will plan to organise lectures onsame subject with different point of view, in addition tointroduce most recent topics. Figure 3 shows one scene intypical lecture.

Figure 2. Picture taken when the beam-on switch ispushed.
Another duty of the operator is watching the machine
status under instruction of the shift leader. If stored beam
was lost, for example, the alert signal appears in the screenof the central control room with computer voice. The
operator broadcast information on the trouble such as "Thestored beam was aborted. The cause of the abort is underinvestigation". The candidate for cause of the abort is shown
in GUI [3,4,5]. The operator checks the cause and cure it incase of easy trouble, such as large reflected power from RFcavity, arc in RF components, modulator down of linac due
to over current, etc. If the trouble is serious one the shift
leader calls the group leader who can cure the trouble. Thegroup leader will nominate the staff to call. The specialist
will cure the situation.

3 TRAINING
Since the carrier of each operator is different in variousways, we give a lecture for operator to help understandingof accelerator system. The lecture contains accelerator
basics, frontier of what accelerator staffs are doing now andso on. The titles of lectures, which were done upto now, arelisted below.
• RF system of the storage ring
• Ultra high vacuum• Beam monitoring system• Control system of accelerator• Magnets and power supplies• What is COD correction

Figure 3. One scene of lecture on beam diagnostics
beamline.
Another way to give operators information is done by
preparation of some manuals. The operation manual isprepared for linac, booster synchrotron and storage ring.
The details of sub-systems such as how to use GUI, thesystem composition, the typical operation parameters and soon are shown in the manuals. The manual is updated
according to the improvement of the sub-system.
In case of trouble, the operators also refer to the failure
report. This report contains information on the troubles
occurred up to now, what was happened, what was thesource of trouble and how to make recovery from thetrouble. This report helps operators to identify what is thesource of trouble and to find how to deal with it. However,some staffs are forgot to write documents, or they will think
the trouble is not so serious one to write documents. We
cannot prepare the perfect failure reports without omission,because the criteria are not clear now. We will improve thissituation in the near future.
The most practical training is experience of daily
operation. The newcomer works with senior operators for agiven period of time before attending to the nights' shift.
The load of the newcomer is increased as his skill is making
progress.
During the long shutdown period (two-months summershutdown, one-month winter shutdown, and two-weeks
shutdown in spring and autumn,) the operators are assigned
to accelerator staffs and work on maintenance jobs such asalignment of magnets, exchange of vacuum chamber,maintenance of VME and so on. Through these work theybring about better understanding on accelerators.
Some of operators are working on making a GUI. The
operator uses GUI daily. So it is nice to make GUIs bythemselves because they can modify the GUI to userfriendly one. The online manuals of GUIs are prepared byoperators. Figure 4 shows an example GUI. The online
manual is updated when some GUI is modified.

Figure 4. An example of online manual for a Graphical
User Interface.

4 SUMMARYThe SPring-8 is successfully operated for these years. We
make some lectures to operators and staffs to improveunderstanding of accelerator operation. We provide
operation manuals to refer when something wrong has
occurred. Further efforts will be made to promote the abilityof operators.

5 ACKNOWLEDGEMENTS
The author would like to thank staffs and operators ofaccelerator division of SPring-8, Drs M. Takao and K.
Soutome, especially to Mr K. Kobayashi and to Dr H.
Ohkuma6 REFERENCES[1] H. Ohkuma, et al, "OPERATIONAL PERFORMANCEOF THE SPRING-8 STORAGE RING" PAC'01, Chicago,June 2001
[2] H. Tanaka, et al, "Recent progress of the SPring-8facility" APAC'01, Beijing, Sept. 2001
[3] M. Takao, "Software application for SPing-8 accelerator
operations" WAO'03 Hayama, March 2003.
[4] T. Ohshima," Machine troubles during user time at theSPring-8", ARW'01 Grenoble, March 2001
[5] M. Kodera et al, "A video monitoring system for SPring8 accelerator tunnel" WAO'03 Hayama, March 2003.