Minutes of the 37th MT Committee Meeting
Date and time: October 15, 2010; 13:30–15:00
Place: Nishina Bldg., Room 201
Attendees: Sakai (Chair), Aoi (on behalf of Sakurai), Fukunishi, Kambara, Kamigaito, Kase, Kubo, Morita,
Uesaka (on behalf of Shimoura), Ueno, Uwamino, Yamaguchi (on behalf of Kubono), En’yo(observer), Inabe (observer), Motobayashi (observer)
Absent: Kubono (CNS), Sakurai, Shimoura (CNS), Wakasugi, Yoshida (observer)(no particular order)

Reports
1. Status reports on beam-time (BT) operationzCommissioning¾238

U commissioning (Kamigaito): Properties of a gas stripper studied for 238U beam acceleration¾SHARAQ commissioning (Uesaka): Methods and procedures studied to realize designed
dispersion matching with the SHARAQ spectrographz

BT operation¾

Series of BigRIPS/SHARAQ experiments with AVF-injected beams (Fukunishi)
Although there was trouble at the beginning of the series, a 97% beam-delivery ratio (88% withdelay taken into account) was finally achieved. Also, beam current was almost as high as ∼400pnA.

¾SHE experiment (Morita)
Total beam dose this autumn corresponds to 1/10 of the “1 event upper limit”.

2. Radioactivation of BigRIPS related to this autumn’s 48Ca-beam series (Inabe)zInfluence on the installation of a pillow-seal system next summer
The effective dose of the STQ-D1 part of BigRIPS should be lower than [100 μSv/day & 200 μSv/h]× [operational working time ∼ 30 min.]. Based on the data obtained in 2008 & 2009, a 48Ca
beam-dose limit is empirically estimated as 4900 pnA×day, which corresponds to 200 pnA × 41 days
× 60%.

zProtecting STQ1 against radioactivation
A dose of 460 μSv/h at a distance of 50 cm is acceptable and can be achieved by installing aradiation shield around F0-STQ. This is possible under the above conditions for a beam-dose limit of4900 pnA×day.

z

This autumn, the 48Ca series will be terminated when the beam-dose exceeds 4900 pnA×day. The
Machine-Time Committee chair will announce when such termination is considered necessary.

3. Database project for RI beams produced at the RIBF facility (Inabe)z

The RI beam data accumulated through the various RIBF experiments, such as production crosssections and purity, are being analyzed by BigRIPS-T and will be incorporated in a database. So faranalyses has been completed of the data for November and December 2008. Analysis of remaining

data is in progress.
z

The data analyzed so far will be made public by the end of October.

z

We plan to call for BT scheduling requests for BigRIPS-based experiments in November.
BigRIPS-T should consider proposing a BT experiment to gather data. (Sakai)

4. Status of the PAC meetingsz

8th NP-PAC (Dec. 3–5)
¾Call-for-proposals was closed on October 8. Twenty proposals have been submitted.

¾An in-house technical review is being conducted Oct. 12–19.

¾

Follow-up evaluations of completed experiments and re-evaluation of non-completed approved
experiments are under preparation.

5. Repair and check of SRC cavities
z The repair and check of SRC cavities will be conducted during the accelerator tuning for theupcoming 48Ca series.
Next MT Committee meeting
zThe next MT Committee meeting will be held on Friday, November 19, 2010, from 13:30 to 15:00.