Ⅱ-9. Instrumentation

RIKEN Accel. Prog. Rep. 47 (2014)

Installation of SLOWRI-1†
M. Wada,∗1 T. Sonoda,∗1 I. Katayama,∗1 P. Schury,∗1 Y. Ito,∗1 F. Arai,∗1,∗2 S. Arai,∗1 K. Kusaka,∗1T. Fujinawa,∗1 T. Maie,∗1 H. Yamasawa∗1 and H. Wollnik ∗1,∗3
The installation of SLOWRI1) , a principal facility
at RIBF that will provide low-energy, high-purity RIbeams of all elements, started in FY2013. SLOWRI
consists of two gas catchers (GasCell-A and -B), mass
separators, a 50-m beam transport line, a beam coolerbuncher, and lasers.
The necessary infrastructure was prepared in thesummer of 2013. Two 400-mm-diameter holes in theshielding block were drilled for the beam transport line.
A 3.5-m long hole was drilled between the laser room
and BigRIPS room for creating a laser path. A staircase was closed by a steel roof to extend the SLOWRI
experimental room. The cable rack of BigRIPS was
modiﬁed, and the electronic racks and compressors forthe cryogenic cooling system were relocated to install
GasCell-A. Large concrete blocks were also relocatedto install the mass separator for GasCell-B. A laser hut
was built to install pulsed lasers, and utilities for thehigh-power lasers were prepared.
GasCell-A (RF carpet gas cell)2) will be installed at
the exit of the D5 dipole magnet of BigRIPS. The gas
catcher contains a large cryogenic He gas cell with alarge traveling wave rf-carpet3,4) . It will convert themain beams of BigRIPS to low-energy, low-emittancebeams without any restrictions on the chemical properties of the elements. GasCell-B (PALIS)5) will be
installed in the vicinity of the second focal plane slitof BigRIPS. It will provide parasitic RI beams fromions lost in the slits during other experiments. In thisgas catcher, thermalized RI ions quickly become neutral and will be re-ionized by resonant laser radiations.
These gas catchers will be ready for oﬀ-line testing byMarch 2014.
The 50-m beam transport line under installation(Fig. 1) consists of four dipole magnets (SD1 to SD4),
two focal plane chambers, 62 electrostatic quadrupole
singlets, 11 electrostatic quadrupole quartets (EQQ1to EQQ11), and 7 beam proﬁle monitors (BPMs). SD1and SD2, located immediately after the gas catchers
will be used for isotope separation. After eliminating contaminant ions at the focal plane chamber, thelow-energy beam will be transported by FODO lattice structures with phase space matching using EQQs.
The EQQs have multipole elements made of 16 rods onwhich various potentials can be applied to produce 6pole and 8-pole ﬁelds, simultaneously, to compensate
for ion optical aberrations. This multipole element canalso produce dipole ﬁelds for steering and scanning the∗1∗2∗3

RIKEN Nishina Center
Department of Physics, Tsukuba University
Department of Chemistry and Biochemistry, New Mexico
State University- 203 -Fig. 1. Part of SLOWRI beam transport line, under installation.

beam. The BPMs have a classical cross-wire beam
monitor as well as a channel electron multiplier with apinhole collimator. Combining the scanning capabilityof the EQQs and the pinhole detector, we can observea beam proﬁle even for very low-intensity RI-beams.
In the SLOWRI experiment room, a beam coolerbuncher6) and a multi-reﬂection time-of-ﬂight mass
spectrograph7) will be installed for conducting various
precision experiments.
Oﬀ- and on-line commissioning will take place inFY2014, and the low-energy RI-beams will be provided
for users in FY2015.
References
1) M. Wada et al., Hyp. Int. 199 (2011) 269.
2) M. Wada et al., Nucl. Instr. Meth. B204 (2003) 570.
3) G. Bollen, Int. J. Mass Spectrom. 299 (2011) 131.
4) F. Arai et al., Int. J. Mass Spectrom., in press.
5) T. Sonoda et al.: In this report.
6) Y. Ito et al.: In this report.
7) P. Schury et al.: In this report.