Minutes of the 58th Machine-Time Committee Meeting
Date and time: September 21, 2012; 13:30–15:10
Place: RIBF Bldg., Room 203a

Attendees: Sakai (Chair), Aoi
Motobayashi
Nakagawaa, †a, †d, †, ‡a, Nishimura, Uedaaaaac †, Abe , Fukunishi , Kamigaito , Kase , Kubo , Miyatake , , Morita a,a, †baaaab†‡

TV Attendee, Shimoura , Ueno , Uesaka , Uwamino , Wakasugi , Yamaguchi ,a, †aAbsent: En’yo a, †, Haba a, †, Sakurai , Sudaad, †, Yoshida

RNC /ba, †c

CNS / KEK /d

RIBF-UEC /Observer /(in random order)
Reports
1.

Changes of the beam-time schedule (Ueno)
It was reported that the beam-time (BT) schedule from the end of July to the end of September waschanged on August 6 due to the trouble of a vacuum pump equipped with the beam injection-extraction
system of RRC that occurred on July 27. The modifications are summarized as follows:
Exp.-Prog.-Num.
AVF-RRC:
NP0802-RRC53-07 (Matsuo)

2.

previouschanged

Jul 28, 21:00 – Jul 30, 9:00

→Sep 12, 21:00 – Sep 14,9:00

NP0709-RRC39-04 (Nagatomo)

Sep 16, 9:00 – Sep 20, 9:00→

Sep 19, 21:00 – Sep 23, 21:00

IB0702-RRC01-56 (Abe)Sep 21, 9:00 – Sep 21, 13:00 →Sep 25, 9:00 – Sep 25, 13:00

ML0901-RRC20-19 (Izumi)

Sep 21, 13:00– Sep 21, 19:00 →Sep 25, 13:00 – Sep 25, 19:00

RI0702-RRC04-09 (Haba)

Sep 24, 9:00 – Sep 26, 9:00

MS10-EXP12-10 (Hirayama)

Sep 28, 21:00– Sep 30, 21:00 →→Oct 1, 9:00

– Oct 2, 21:00

Sep 28, 21:00 – Sep 30, 9:00

RRC repair (Kase)The upper main coil of the RRC E-sector magnet
As continuously reported from January, a layer short has occurred at the upper main coil of theE-sector magnet, which causes the reduction in the magnetic field of 100 ppm and the instability of
20 ppm of RRC. Since the short position was identified inside the coil, and thus a quick fix wasimpossible, the upper magnet yoke of RRC was dismantled, and the coil was replaced in August.
After a magnet excitation test, RRC was put into operation. There was no trouble after the repair.

The lower main coil of the RRC W-sector magnet
In addition to the above-mentioned E-sector coil short, another layer short occurred in June in thesame place in the W-sector main coil that was damaged and repaired in 1999. After an emergency
repair, RRC was put into operation. Since a full repair will take more than one month, no further
repair will be done for the near future.

3.

Status of the BT scheduling for the FY2012 second half (Ueno)
It was reported that the BT scheduling procedure prior to the approval by the MT Committee had been
completed according to the schedule explained in the previous meeting. In this procedure, a BT plan wasdiscussed by a working group formed under the MT Committee on August 13, and safety aspects of eachexperiment were reviewed by the In-House Safety Review Committee meeting held on September 11.
4.

Status of PAC meetings (Ueno)


NP-PAC: Despite the previous announcement that the 12th NP-PAC will be held on Dec. 10–11, it
was determined by the 124th RNC-CNS Research Collaboration Liaison Meeting to postpone thePAC meeting because the BT of RIBF SRC-use experiments in the second half of FY2012 wasreduced, as explained below in Discussion 2.

9th ML-PAC: The PAC meeting was held on September 4–5 as scheduled. A total BT of 51.9 days
was proposed for the use the RIBF facility. A PAC report will be submitted to the RNC and RAL
directors soon.

Topics discussed
1. Approval of the minutes of the previous meeting (Sakai)
2. BT schedule of FY2012 second half (Sakai)
The RNC director decided on August 7 to limit the RIBF-SRC operation to one month in November,and to suspend the operation of the RIBF low-energy part using AVF, RILAC, and RRC except forthe SHE research, due to budgetary constraints. A BT schedule, planned by an MT Committee
working group (WG)

*1, 2

on August 13 in accordance with the above-mentioned decision, wasdiscussed. In the plan, BTs in the AVF standalone mode were scheduled, since their energy
consumption level is much smaller than that of the RIBF-SRC operation. (Ueno)*1

The WG was temporarily formed under the MT Committee as provided in the Article 6 ofRIBF MT Committee Bylaws.
*2The WG members are: Sakai (MT Committee chair), Abe, Fukunishi, Haba, Kase, Kubo,Motobayashi, Nishimura, Sakurai, Shimoura, Ueno, and Wakasugi, from the MT Committee,Okuno Deputy Group Director, Ikezawa Team Leader (TL), Nakagawa TL, and Sakamoto
TL.
After some modifications such as the cancellation of the SHE research, the BT plan was approved. It
was noted that the RIBF-SRC operation will be extended to December–January if the budgetarysituation of RNC shows improvement. Furthermore, according to the RNC director’s decision asmentioned above, BTs of the RIBF low-energy part, including the newly approved experiments by
the 9th ML-PAC for February and March have been suspended, although it had been previously
announced to schedule them separately.

For the convenience of RIBF users, the almost finalized BT schedule for the second half of theFY2012 has been disclosed prior to the approval by the MT Committee. It was suggested that a BTschedule should be disclosed by supplementing a note that says “to be approved by the MTCommittee”. It was also suggested to have the NP-PAC meetings one month ahead from June to May
so that a BT schedule can be approved and fixed by the MT Committee at the meeting held in July(the meeting is usually adjourned during August). (Fukunishi)

3. Current status and future prospect of beam development (Kamigaito)
The priority of the kind of heavy ions to be developed is determined by taking into account theirfeasibilities and necessities in the next two years’ time. The feasibilities are discussed not only interms of technical issues but also the availability of the accelerators (i.e., the BT schedule). Currently,
the highest and second priority heavy ions are 238U and 48Ca, respectively, for which the Accelerator
Group is developing a new oven system equipped with the ion source for the start of its operation inspring 2013.

In the meeting, heavy ion candidates for the third priority were discussed. Based on the discussions,beam development plan will be prepared by the MT Committee, and reported to the RNC director
and the deputy director for consultation. Then, the start of their beam deliveries will be determinedby taking into account man power for the R&D studies, availability of the ion sources, a strategy ofthe SHE research, and a possibility of R&D collaboration with other institutes. This will be achievedby investigating the technical issues and the degree of urgency for each beam.

It was pointed out that the beams that many potential users hope to make use of might be missing
from the list of beam supply discussed above, since the most of the proposed and approved
experiments from which the list had been constructed are designed based on the list of available
beams open to public. The RIBF User Group will consider conducting the survey and submit theresult to RNC as an input for the priority setting. (Aoi)

4. Next meetings
The next meeting will be held on Friday, October 12, 2012, at 13:30

The meeting after the next will be held on Friday, November 16, 2012, at 13:30