Minutes of the 89th Machine-Time Committee Meeting
Date and time: June 16, 2015; 15:00–16:30
Place: RIBF Bldg., Room 203
Attendees: Sakai a (Chair), En’yo a, †,Fukunishi a, Kamigaito a, Kase a, Kubo a, Miyatake c, Morimoto a, Sakurai a,Shimoura b, Ueno a, Uesaka a, Uwamino a, Wakasugi a, Yamaguchi b, Imai d, †, Haba a, †,Motobayashi a, †, K. Yoshida a, † , Otsu a, †, Kishimoto a, †, Tanaka a, †, A. Yoshida a, †,Yonedaa
Absent: Abe a, Okuno a, Morita a, †a

RNC / b CNS / c KEK / d RIBF-UEC / † Observer(in random order)

Reports
1.

Current Status of the Machine Time Operation (Yoneda)
The current status of the machine time operation was reported. After the last MT committee meeting, theSRC-BigRIPS experiments with 78Kr were performed as scheduled. The schedule was changed as below
and 3-days of MT were newly allocated to the new isotope search experiment due to a new possibility ofproducing new isotopes in the proton-rich region with the current beam setting.

2.

(before change)(after change)

DA14-02 (Kubo)(Newly allocated)

6/16 9:00 – 6/19 9:00

MS-EXP15-04(Yamaguchi)

6/16 9:00 – 6/19 9:00

6/16 9:00 – 6/22 9:00

Changes of the Machine Time Schedule of Low-Energy Facility (Yoneda)
The changes of the MT schedule of the low-energy facility were reported. The RILAC standalone
experiment DA13-02(K. Morita, 50Ti, GARIS), originally scheduled to go until 9am of June 12 wasextended by one day to go until 9am of June 13 since an additional change of the ion source material wasrequired during the experiment. The experiment was conducted with 48Ti from halfway through theexperiment since the 50Ti supply from the ion source became unexpectedly small.

3.

Report on the RIBF Accelerator Operation（Fukunishi）
A status report was made concerning the beam provided to the SRC-BigRIPS experiments. The 78Kr
beam was being provided, and the beam intensity so far has been stable with 342pnA at maximum,200-280pnA on average. The beam availability was 89.6%, due to some troubles such as the replacementof the vacuum tube used for SRC RF.

4.

Report on the Restriction of the 78Kr Beam Intensity (Tanaka)
A report was made concerning the restriction of the 78Kr beam intensity. Radiation close to the limit ofrestriction (2.6µSv/h) was observed at the boundary of the radiation-controlled area on the first floor due
to the radiation from the transfer beamline between SRC and BigRIPS. The restriction of the 78Kr beam
intensity was thus newly introduced at 200 pnA. The committee shared a view that such type of
restriction could happen with other beams such as 48Ca, and the radiation shield for the beamline between

SRC and BigRIPS must be reinforced as originally required in the building plan.
5.

Report on the Schedule of the Facility Inspection (Uwamino)
A report was made concerning the schedule of the facility inspection. The inspection will be performed inthe daytime from December 1 through 3, and during this period beams are needed in RILAC, SRC, andAVF. On the third day, the beam delivery will be interrupted for the interlock tests whenever as requiredby inspection.

6.

Report on Preserving Research Records (Yoneda)
A status report was made concerning the research record preservation.

An instruction on the method ofcopying experimental data and log books was sent to all the experiment groups which conducted
experiments after April this year. Most of the experimental groups made copies of their research records
as instructed, but there were still some groups which have not followed the procedure yet. The progresson the matter will continue to be observed hereafter.
7.

Status of PAC Meetings （Yoneda）
・ 16th NP-PAC:（12/3 – 5）
The call for proposals will be issued in September, with the deadline of proposal submission late inOctober.
・ 12th ML-PAC：(to be held in July):
The schedule is under consideration, based on the backlog of experiments using the low-energy facility
and status of RAL experiments.
・ 4th In-PAC：nothing has been finalized about the next PAC.

Topics discussed
1. Approval of Minutes of Previous Meeting (Sakai)
2. Additional MT Allocation to RIPS Experiment (Schury)
An additional MT allocation to a RIPS experiment was proposed by ULIC. The proposal is to assign threedays of beam time to the Teranishi group (AVF+RRC, 12C@70MeV/u, >200pnA, E6(RIPS)) from 9am,
September 5 through 9am, September 8, a slot that has opened up due to an experiment cancellation. The
allocation was approved as proposed.
3. Application of Machine Study
・Machine Study for NeuLAND efficiency measurement (Otsu)
A machine study was proposed for a neutron detector NeuLAND. NeuLAND is a plastic scintillator
produced for GSI FAIR, and is to be used for the collaboration experiments at SAMURAI until FAIRstarts. The detector has four walls of scintillators, each with two layers of scintillators (250cm x 250cm,5cm thick), and is scheduled to be used for at least seven experiments including the 28O resonant statesearch. The structure is preferable for multi-neutron detection. The efficiency of this detector will becalibrated using the (p,n) reaction on a 7Li target. One can expect to estimate efficiencies with 10%
accuracy based on simulation, a guess based on experiences using NEBULA, and 5% of precision will beachieved by actually measuring neutrons. Two proton beams with energies of 250MeV/u and 100MeV/u
will be produced as the secondary beams from 48Ca (0.5 days), and the efficiency will be measured
through detecting neutrons emitted forward by the (p,n) reaction (0.5 days).
As a result of the review, 1-day measurement was approved in principle, though additional explanation
was requested so that its necessity would be better understood.
4. FY2015 Yearly MT Plan (Sakai)
The yearly MT plan for the fiscal year 2015 was shown by ULIC for the exchange of opinions. The beamtime request for the period from October through March was closed on June 15. Four 238U experiments,
four 48Ca experiments and two 70Zn experiments using SRC-BigRIPS were requested. It was proposed
that, as discussed in the last MT committee meeting, about a month of the 238U beam experiments(including the ImPACT experiment) and the 48Ca experiments hereafter will be assigned, to which noobjection was raised.
5. Next Meetings
・The next meeting will be held on Tuesday, July 14, 2015, at 3pm.

・The meeting after the next will be held on Wednesday, September 2, at 1:30pm.