Ⅰ. PREFACERIKEN Accel. Prog. Rep. 47 (2014)

Preface
The RIKEN RI Beam Factory has reached its harvest

The proposal was approved and the first beam time wastime. From its commissioning in 2006 to 2013, 71

already allocated. Somewhat different from our traditional

experiments have been performed with 238U, 124Xe, 86Kr, 70Zn,

style

48

Ca, 18O, 14N, and 4He beams from the Superconducting

experimentalists to form a bigger and tighter collaboration.

Ring Cyclotron (SRC) and the isotope separator BigRIPS.

The Nishina Center appreciates an understanding by all usersThe SRC recorded its highest 238U current of 25pnA in 2013,of the necessity of such an approach, and promises its faira performance far beyond that of any other accelerator

operation to the user community.

ofproposal,

thenewscheme

requiresthefacilities in the world. This edition of Accelerator Progress

As we have now reached the stage to reap the harvest ofReport highlights the history of RI delivery at the RIBF in its

the RIBF research, many interesting results are being

gravure pages. While some are yet unpublished, we shouldpublished. In 2013, we issued three press releases on thebe proud that more than 100 new isotopes have been

RIBF experiments, “Discovery of exotic isomers with a

discovered at the RIBF.

magic number”, “Evidence for a new nuclear magic number

Our RI beams attract many users from all over the world.

of 34 --- a key to access a dream region of island-of-stability”,

Following the great success of the EURICA (Euro-Rikenand “Magic numbers’ disappear and expand area of nuclear

Crystal Array) campaign, MINOS, a state-of –the-art setupdeformation”. The Nishina Center thanks and congratulateswith a hydrogen target and a vertex detector, arrived fromall those involved in these experiments, and is convinced thatSaclay, France. A large-scale Time Projection Chamber to be

this trend will continue to grow in the future. It should beinstalled in the SAMURAI spectrometer has recently arrived

noted and appraised that in 2013, prestigious prizes werefrom the USA. Furthermore, other detectors like NeuLand

given to the staffs in our accelerator group for their record-(highly segmented neutron time-of-flight counters frombreaking accelerator operation, especially with the gasGermany) and BRIKEN (hundreds of neutron counters fromstripper developments.

the USA to surround the target) are to be shipped to the

Unfortunately, JFY2013 did not close peacefully. The STAPRIKEN RIBF.

incident, a serious scientific misconduct that occurred at theTo effectively explore new regions in the nuclear chart

RIKEN Center for Developmental Biology has affectedusing such devices, we have introduced a new scheme ofRIKEN severely. I apologize for any inconveniences you

experimental proposal, Proposal for Scientific Project. Withhave had to deal with to in complying with RIKEN’s

this new scheme, experimentalists are asked to propose acountermeasures. If any similar incident ever occurred at theseries of experiments based on common physics interests thatNishina Center, the Center would cease to exist. We thus

uses the same experimental apparatus and targets not just one

declare that such an incident will never happen in our field.

or two nuclei but a wide region of nuclei.
Under this new scheme, the SEASTAR project

Hideto En'yoDirector,
RIKEN Nishina Center for Accelerator-Based Scienceemploying the MINOS and the DALI2 detectors wasestablished to aim for a systematic search of new 2+ energies
in the wide range of the neutron-rich nuclei accessible with
the RIBF's currently available 70Zn and 238U beam intensities.

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