volume . 005
April 2009

Dear RIBF users
This is the 5th issue of the RIBF Quarterly with the most up to the minute information on our RI
Beam Factory. The back numbers are available at our web site:
http://www.nishina.riken.jp/UsersGuide/

Present status, operation schedules of RIBF
Beam Time schedule

3. BigRIPS

The beam time schedule of the first half of thisfiscal year, April to Sept., are available at http://www.nishina.riken.jp/rarfmt/pc.html.

This summer, to facilitate maintenance underhigh residual radiation, the remotely releasablemechanism, “pillow seal”, will be installed at
the RI-beam production parts of the BigRIPS,
specifically those for both the production-target
and beam-dump areas. By this installation,
BigRIPS will be able to accept full-intensity
primary beams. Simultaneously, a constructionof additional shielding in these areas will beconducted to reduce heat loads and radiation
damages of the air-core quadrupole magnet placeddownstream of the target chamber.

The beam time requests are called twice a year,
usually in July and in January, to all the spokespersons
having valid PAC approved experiments. Based on
their requests, the beam time schedule is fixed forevery half year, which starts from April and October.

A new RIBF acceleration scheme andSHARAQ commissioning
In the middle of last March, a new acceleration
scheme was tested, namely AVF - RRC - SRC
skipping IRC. The 250-MeV/u 14N beam was
successfully accelerated, and delivered to a newly
constructed SHARAQ for its commissioning.

Recent Developments
1. Towards intense heavy ion primary beams

Nishina Center
http://www.nishina.riken.jp/
PAC related
http://www.nishina.riken.jp/UsersGuide/
RIBF User Group
http://ribfwww.riken.go.jp/exp/RIBF_uec_eng/
Beam Time Schedule
http://www.nishina.riken.jp/rarfmt/pc.html
Seminar information
http://rarfaxp.riken.jp/~seminar

4. other constructions
Construction of a new gas-filled recoil separator,
GARIS-II, dedicated to chemical- and spectroscopicstudies of SHEs produced by ‘hot fusion’ reactions,has been completed. Its commissioning will start
this summer.
As announced in the last RIBF Quarterly 4, theFY2008 supplemental budget from the government
was approved for constructions of a new injector
linac, RILAC II, and an electron storage ring, SR2.
Both constructions have started. The RILAC II
will be completed in the next March, and 300MeV electron beam for eRI scattering will start tocirculate in the year 2009.

The superconducting ECR ion source has been
installed and is now being tested on site. It is
expected that a few pnA U beam will be available
for BigRIPS experiments this fiscal year, which isabout one order higher than that of the last year.
A new beam line connecting to the RILAC is also
under construction. The operation of this newsystem will soon start.

Operation plan of this fiscal year

2. Charge stripper development

1. BigRIPS experiments

Last February, intensive efforts were made tocharge-stripper developments in collaboration
with MSU. A gas-stripper system using nitrogengas was tested for Xe and U beams. The Xe andU beams were accelerated up to RRC, and thecharge-state distributions were measured after
the stripper. It was found to work perfectly for
Xe beam; the charge state optimum for following
acceleration was obtained, promising accelerationof an intense Xe beam with good stability. One
can expect a few 10 pnA Xe beam. The intensityand beam quality will be confirmed by accelerating
Xe beam upto SRC in this coming June. For U
beam, however, it was not the case; the obtainedcharge state was unfortunately much lower than
expected. For U beam, we will continue to develop
a charge stripper system.

April - May : commissioning and tests(AVF-RRC-SRC mode)
June : primary beam development (U, Xe, Zn)

Nishina Center for Accelerator-Based Science.

.1.

Oct. - Dec. : BigRIPS experiments with highintensity primary beams
AVF-RRC-SRC, RILAC-RRC-(fRC)-IRC-SRC modes2. Other experiments
Due to the construction and installation of thenew injector heavy-ion linac, RILAC II, in the
AVF hall, AVF will not be available in the period
from Jan - March, 2010. In the period from Feb.
to March, no RIPS experiment will be allocatedsince the RIPS hall, E6, will be also affected by theconstruction.
Toshimi Suda
User Support and Liaison Office
UserSupportOffice@ribf.riken.jp

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2 0 0 9Announcement
Nishina Center Advisory Council

volume . 005
April 2009

The activities of Nishina Center were reviewed bythe Nishina Center Advisory Council (NCAC) heldin Jan. 15-17, 2009. The NCAC report submitted
to the president of RIKEN, Prof. R. Noyori, is now
available on the RIKEN web site at
http://www.riken.jp/r-world/info/report/nishina/nac/2009/report09.pdf

PACThe 5th Nuclear Physics PAC meeting will beheld in June 18 and 19. We are now calling forproposals, and the submission deadline is May
15. For further details, refer to “call for proposals”
available at
http://www.nishina.riken.jp/UsersGuide/NP-PAC.

The schedule of the 5th Material and Life science
PAC meeting is now being discussed. The details
will be announced in the next RIBF Quarterly.

Beam Time Requests
We will start to call for beam time requests forthe latter half of this fiscal year, from Oct. 2009 toMarch, 2010. The “call for beam time requests”
will be sent in the beginning of July to all thespokespersons of the PAC approved experiments.
At the same time, we will also call for requests
of “Detector Development Beam Time” dedicatedto detector development activities using the AVF
in the stand-alone operation. The call will be sent
to all the RIBF users.

User Group Activities
The town meeting of RIBF Users Group washeld in March 27 at Rikkyo University during theJPS annual meeting. Slides used in the meetingare available at
http://ribfwww.riken.jp/exp/RIBF_uec_eng.

The UEC meeting was held on April 15 at RIBF.
The minutes will be posted by the UEC members.

Recent News and Research topics of RIBF
Research Incentive Awards of RIKEN for
FY2008identification of the isotopes of the 113th element.
The paper is in press.

T. Ohnishi, H. Takeda, N. Fukuda, D. Kameda
and Y. Yanagisawa (BigRIPS team)“Identification of New Isotopes 125Pd and 126Pd
produced by In-flight Fission of 345 MeV/nucleon
238
U“Direct observation of carrier trapping on57
Fe impurities in multi-crystalline Si solar
cell under light illumination

M. Ito (Theroretical Nuclear Physics Lab.)“Unified studies of chemical-bonding structuresand reaction dynamics in the highly-excited statesof Be isotopes”

Additional strong evidence of the Z=113
discovery
A series of 266Bh production experiments, 23Na +Cm -> 266Bh + 5n, has been conducted from theend of Dec. 2008 to the end of Feb. 2009 throughthe new-year holidays. The nucleus 266Bh appears
as the great-grand daughter of 278113 in its decay
chain discovered by a research group at RIKEN.
Over 20 266Bh events have been produced and thedecay properties of 266Bh and its daughter nucleus
262
Db have been studied in details. The decay
properties were found to be consistent with thoseobserved in the 278113 decay chain, which provided
a further confirmation of the production and248

Using energetic 57Mn secondary beam produced
by RIPS, Y. Yoshida (Shizuoka I.S.T.) and hiscollaborators successfully observed drasticchanges of the Moessbauer spectrum of 57Fe deeply
implanted in multi-crystal solar cells under lightillumination. The carrier trapping process by Fe
impurities in the solar cells is considered to be
one of the main reasons of the degradation of thepower generation efficiency of the solar cells. Theirresearch will shed lights on how Fe impurities areharmful in solar cells.

First demonstration of an electron scatteringexperiment with SCRIT
Further progress of the SCRIT development
has been recently published, PRL 102 (2009)
102501. Using the novel SCRIT technique, themeasurement of elastic electron scattering has
been successfully performed for the first time withmuch improved luminosity. The SCRIT grouppublished two PRL papers in FY2008.

Nishina Center
http://www.nishina.riken.jp/
PAC related
http://www.nishina.riken.jp/UsersGuide/
RIBF User Group
http://ribfwww.riken.go.jp/exp/RIBF_uec_eng/
Beam Time Schedule
http://www.nishina.riken.jp/rarfmt/pc.html
Seminar information
http://rarfaxp.riken.jp/~seminar

Nishina Center for Accelerator-Based Science.

.2.

Toshimi Suda
User Support and Liaison Office
UserSupportOffice@ribf.riken.jp

A p r i l

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