Ⅱ-9. Instrumentation

RIKEN Accel. Prog. Rep. 47 (2014)

New laser system installation for PALIS
T. Sonoda,∗1 H. Iimura,∗2 M. Wada,∗1 I. Katayama,∗1 Y. Adachi,∗3 T. Noto,∗3 T. Takamatsu,∗3 T. Takatsuka,∗3H. Tomita,∗3 F. Schneider,∗4 K. Wendt∗4 F. Arai∗5 Y. Itou∗5 P. Schury∗5 and the SLOWRI collaboration
A new laser system for PArasitic slow RI-beam production by Laser Ion Source (PALIS)1) has been installed. This system has higher laser power and repetition rate compared to those previously we used. Agas-jet laser spectroscopy can be applied owing to highrepetition rate. A room partition was recently constructed for the laser equipments having laser shieldnoise barriers. The room is complete with an air conditioning system.
So far, we have developed a resonant ionization laser
system and a new laser ion source conﬁguration for future PALIS project. Old laser components consist of
two pulsed dye lasers (Lambda Physik) pumped by
two excimer XeCl lasers (Lambda Physik). The maximum power and repetition rate for the excimer laser
is 150 mJ/pulse, 200 Hz, which corresponds to 30 W.
Additionally, Ti:Sapphire laser pumped by YLF laser(10 W, 1 kHz) is available through collaboration withNagoya university. By using these lasers, oﬀ-line resonant laser ionization for stable Co, Cu, Fe, Ni, Ti, Nb,Sn, In, and Pd inside the gas cell, ion extraction andtransport to high-vacuum region via SPIG and QMS
have been conﬁrmed2) . The feasibility study for thegas jet laser spectroscopy was investigated in combination with dye and TiSa lasers3,4) .
In terms of the eﬃciency of the gas cell based resonant laser ionization system, the laser power and its
duty cycle are important. The ionization eﬃciency depends on the atomic transition strength determined by
the type of the element. High power lasers are widelyadopted for a number of elements. Moreover when themoving speed for photo-ionized atoms increases as in
the case of ionization inside a gas jet, the duty cycleof the laser pulse should be set suitably high5) . Thus,a high power and high duty cycle laser is necessary torealize a higher performance PALIS system.
In FY2013, the construction budget for a low-energy
RI-beam facility SLOWRI was ﬁnally founded. New
high power, high duty cycle lasers were prepared for
PALIS experiments. In order to install the new laser
assembly, the room size for laser setting and oﬀ-line
experiment was also extended.
New laser components consist of two pulsed dyelasers pumped by one YAG laser. The maximum repetition rate and power for a YAG laser (Edge wave) is10 kHz and 90 W for 532 nm with a single mode and36 W for 355 nm and 40 W for 532 nm with a mul∗1∗2∗3∗4∗5RIKEN Nishina Center
Japan Atomic Energy Agency
Faculty of Engineering, Nagoya University
Institute of Physics, Johannes Gutenberg University
Institute of Physics, Tsukuba University- 210 -timode. Two pulsed dye lasers (Sirah) provide a wide
range wavelength from 215 to 900 nm with about 10W for fundamental frequency and 1 W for a frequencydoubled by a secondary harmonic generator. These dyelasers accept both wavelengths (355/532) from pumplaser beam and have an additional option for selecting a line width of 1.5 GHz and 6 GHz, alternately.
Additionally, a new YAG laser (Lee) was installed forpumping Ti:Sapphire lasers. The maximum power andrepetition rate is 50 W and 10 kHz, respectively. An
injection locked Ti:Sapphire laser operated at up to 10
kHz with a line width of 20 MHz will be prepared forhigh precision laser ionization spectroscopy.

Fig. 1. The photograph of new PALIS lasers: shining two
dye lasers pumped by YAG laser.

We conﬁrmed that the new laser system works witha reasonable performance. Fig. 1 shows a photographtaken during tests of the new lasers in October 2013.
The oﬀ-line and on-line commissioning test for PALIS
will begin from April 2014.
References
1) T. Sonoda et al.: AIP Conf. Proc. 1104 132 (2009).
2) T. Sonoda et al..: Nucl. Inst. and Meth. B 295 1(2013).
3) C. Sakamoto: Master thesis, Nagoya University (2013).
4) T. Takatsuka et al.: Nucl. Inst. and Meth. B 2951(2013).
5) T. Sonoda et al.: Nucl. Inst. Meth. B 267 2918 (2009).