For Users | Research Center for Accelerator and Radioisotope Science (RARIS), Tohoku University

For Users

Announce　・　Apply Proposals　・　Approved Proposals　・　Machine Schedule　・　
Facilities/Beam Lines　・　Radiation Control Office

Announce

No announcement at this time.

Apply Proposals

　
Currently we accept research proposals only written in Japanese, but we prepare to accept those in English.

Usersoffice Mail: usersoffice @ lns.tohoku.ac.jp, Phone: +81-22-743-3435

Research Proposals

YEAR	APPROVED PROPOSALS	-
2016	TBD

Machine Schedule

Latest Schedule （PDF）

Facilities/Beam Lines (Accelerators/Beam Spec)

Beamlines Summary

We provide beams by following three beam lines (as of 2015).

BEAM LINE　I (RI Experiment)	BEAM LINE　II (Nuclear Physics Experiment)	BEAM LINE　III (Nuclear Physics Experiment)
70 MeV Electron Linac ↓ Irradiation at #1Lab	100 MeV Electron Linac ↓ 1.3 GeV Electron Synchrotron ↓ Irradiation at #2 Lab	100 MeV Electron Linac ↓ 1.3 GeV Electron Synchrotron ↓ Irradiation at GeV Gamma room

Accelerators and Beam properties

In ELPH, the electron and photon beam lines are provided for nuclear physics experiments and a radioactive isotope production. (Present Configuration (2015))

High intensity electron linac

The 300 MeV electron linear accelerator had been constructed in 1967. In the Great East Japan Earthquake (March 11, 2011), serious damages was inflicted on this linac and a low energy part of the linac was reconstructed as a high intensity electron linac. The linac consists of 90 keV thermionic cathode gun, a buncher section and eight 1m-long s-band accelerating structures. Maximum energy of the linac is 70 MeV without beam loading. The linac is operated with 300 Hz repetition rate and a peak current in macropulse is approximately 100 mA with 3 micro-sec pulse duration. The average beam current is about 100 micro-Ampere. This high current electron beam is used for radio isotope production by photonuclear reactions.

Linac Energy	Modulator Repetition	Macropulse Peak Current	Macropulse Duration	Average Current
50 MeV	300 Hz	〜130 mA	3.0 µs	120 µA
30 MeV	300 Hz	〜100 mA	3.0 µs	90 µA

Injector linac for BST

Injector linac for the Booster synchrotron ring.

Compact electron linac had been constructed as the injector for the booster synchrotron in 2012. The injector consists of a thermionic rf-gun, an alpha magnet, two s-band 3m-long accelerating structures, and transport line to the booster synchrotron. The maximum energy of injector is 90 MeV with beam loading. This linac has two beam lines for beam diagnostics, one is straight line and the other is 90 degree beam line with dispersion section.

1.3 GeV Booster-STorage ring (BST)

Combined function magnet. It looks like an ordinary quadrupole magnet but has a special pole-face shape to generate the sextupole component, and thus the chromaticity correction can be accomplished with these magnets by introducing the dispersion function to the magnet location.

BST ring. The ring circumference is 50 m, and eight dipole magnets (blue pieces) deflect the electrons so as to guide the electron beam, while the focusing magnets (orange and red magnets) are used to keep the electrons circulating inside the vacuum chamber.

BST is an electron synchrotron which accelerates the electrons injected from the injector linac up to 1.3 GeV in maximum. The required energy to accelerate and store the electron beam is supplied by a 500 MHz rf cavity. By inserting a very fine carbon wire to the beam orbit of circulating electrons after the acceleration, high energy gamma rays are generated via bremsstrahlung. Two beam lines are operational to utilize such gamma rays. In a typical operation pattern, beam acceleration is immediately started just after the injection and finished within ~2 sec., and then stored electrons with ring current of 10~30 mA are consumed to generate the gamma rays over a duration of about 10~40 sec. Currently available operation energy is 1.3, 1.0 and 0.8 GeV, and typical ring current is ~10～30 mA.

Injection Beam Energy	Injection Repetition	Ring Top Energy	Storage Beam Current
90 MeV	~0.05 Hz (typ.)	0.8~1.3 GeV	~30 mA

Tagged photon beamline

The BST ring has two beamlines providing tagged photons. The typical properties of the tagged photon beams are summarized in the table:

Beam line	Energy Range (Rint Energy: 1.3 GeV)	# of Bins	Intensity	Duty
BST-Tagger-I	0.8 ~ 1.26 GeV	160	TBC	~60% (NKS2)
BST-Tagger-II	0.9 ~ 1.25 GeV	116	TBC	~50% (FOREST)

Photon beamline I

The photons are designed to be tagged with energies of 62%~98% with respect to the circulating electron energy of the BST ring. The number of tagging channels are 160. The details of the photon beam properties are under investigation.

Please contact to Dr. M. Kaneta (mail: kaneta@lambda.phys.tohoku.ac.jp).

Photon beamline II

The photons are designed to be tagged with energies of 62%~96% with respect to the circulating electron energy of the BST ring. The duty facto is approximately 50% (stable photon beam can be obtained for 8.5 s out of a 17 s cycle). The number of tagging channels are 116. The details of the photon beam properties are under investigation. Information before The Great East Japan Earthquake (March 11, 2011) can be obtained in a reference "The second GeV tagged photon beamline at ELPH"

Reference: T. Ishikawa et al., Nucl. Instr. and Meth. A 622, 1 (2010).

Please contact to Dr. A. Tokiyasu (tokiyasu-at-lns.tohoku.ac.jp -at- should be replaced with @).

Positron/electron beamlines for testing detectors

The positrons and electrons, which are produced at a metal plate in front of the bending magnet RTAGX by the photon beam, are provided at three beamlines in the GeV-γ experimental hall. The positrons and electrons are momentum-analyzed with RTAGX, and the energy spread of them is approximately 0.5% . The beam profile and intensity depend on the beam energy, and the diameter of the beam is roughly 20 mm, the intensity is roughly a few kHz. The positrons (or electrons) at the -30 deg beamline can be focused with a triplet quadrupole magnets thanks to a KEK cooperation. The polarity of the magnets can be changed. The details of the photon beam properties after the earthquake are under investigation. Information before can be obtained in a reference "A detailed test of a BSO calorimeter with 100-800 MeV positrons",

Reference: T. Ishikawa et al., Nucl. Instr. and Meth. A 694, 348 (2012).

Beam	Beam line	Maximum beam energy
Positron / Electron	± 30 deg	~840 MeV
Positron	-23 deg	~1000 MeV

Please contact to Dr. A. Tokiyasu (tokiyasu-at-lns.tohoku.ac.jp -at- should be replaced with @).

Radiation Safety

The radiation safety office at Research Center for Electron Photon Science (ELPH), Tohoku University provides safety related services to users of radioactive materials and radiation generating apparatus. The office also conduct regular works to ensure safety for the facility, worker, and the public.

Registration of Radiation Worker

All users of ELPH have to be registered as radiation workers at home facility. Then, the users have to submit “Radiological Work Certificate” form. In addition, the users will take the Radiation Safety Training for ELPH, based on the Japanese law, before you enter the radiation controlled area at ELPH. The registration is valid during 1 fiscal year from April 1 through March 31.

Radiation Safety Training for ELPH

For details, please contact the radiation safety office at ELPH, the contact person of your research group, or your advisor at ELPH.

Maximum Permitted Activity of Unsealed Radionuclides

Staff

Hidetoshi Kikunaga (Nuclear and Radiochemistry)
Toshiya Muto (Radiation Protection Supervisor)
Shigeru Kashiwagi
Manabu Miyabe
Ken'ichi Nanbu
Yumi Sugawara

Contact

Radiation Safety Office
Address: Research Center for Electron Photon Science, Tohoku University
1-2-1 Mikamine, Taihaku-ku, Sendai, Miyagi 982-0826
Phone: +81-22-743-3411
Mail: kanri @ lns.tohoku.ac.jp