New lattice for UVSOR

Katoh, Masahiro; Hayashi, Kenji; Honda, Tohru; Hori, Yoichiro; Hosaka, M.; Kinoshita, Toshio; Kouda, S.; Takashima, Yoshinori; Yamazaki, J.

doi:10.1016/s0168-9002(01)00217-0

Cited by 13 publications

(5 citation statements)

References 5 publications

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“…UVSOR is a low energy synchrotron light source, which had been operated since 1983. After two major upgrades [1][2][3][4], now it is called UVSOR-III [5]. The circumference of the storage ring is 53 m and the electron beam energy 750 MeV.…”

Section: Introductionmentioning

confidence: 99%

Bayesian optimization of the dynamic aperture in UVSOR-IV design study

Salehi,

Katoh

2024

J. Phys.: Conf. Ser.

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A lattice of a storage ring for the future plan of UVSOR synchrotron facility, UVSOR-IV, is designed at 1 GeV electron energy. The lattice of 12 compact double achromat cells conducts to an emittance of 4.2 nm at 1 GeV electron energy and 2.3 nm at 750 MeV electron energy in achromat condition, 82.5 m circumference, and six straight sections of 4 m long and six of 1.5 m long. The lattice requires strong sextupole magnets to compensate the natural chromaticity. To help deal with the challenge of dynamic aperture associated with the strong nonlinearities, we examined improving the dynamic aperture by optimizing the sextupole arrangement based on the Bayesian method. We have demonstrated optimizing the harmonic sextupole strength of four families with 100 iterations of running particle tracking simulation that is much faster than traditional methods such as complete parameter survey.

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Section: Introductionmentioning

confidence: 99%

Bayesian optimization of the dynamic aperture in UVSOR-IV design study

Salehi,

Katoh

2024

J. Phys.: Conf. Ser.

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“…UVSOR is a low energy synchrotron light source, which had been operated since 1983. After two major upgrades [1][2][3][4], now it is called UVSOR-III. The circumference of the storage ring is 53 m and the electron beam energy 750 MeV.…”

Section: Introductionmentioning

confidence: 99%

Lattice design of the UVSOR-IV storage ring

Salehi

Taira

Fujimoto

et al. 2023

J. Phys.: Conf. Ser.

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We are designing a storage ring lattice for the future plan of UVSOR. As a candidate, we have designed a storage ring of 1 GeV electron energy, which is higher than the present value, 750 MeV. The magnetic lattice is based on a compact double bend achromat cell, which consists of two bending magnets and four focusing magnets, all of which are of combined function. The circumference is 82.5 m. The emittance is 4 nm in the achromatic condition, which becomes lower in the non-achromatic condition. The lattice has moderately large dynamic aperture with four sextupole families. The lattice of 6-fold symmetry has six straight sections of 4 m long and six of 1.5 m long. Undulators can radiate nearly diffraction-limited light in VUV. If we install high field multipole wigglers at the short straight sections, they can provide high flux tender X-rays. We are expecting usage of a laser-based accelerator as the injector, which might be developed in the next decade. As an alternative plan, we have designed a traditional injector, which consists of a linear accelerator and a booster synchrotron that can be constructed inside of the storage ring.

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“…In this study to elucidate the feasibility and the detailed mechanism of the photoreaction of amino acids in ice matrices and hopefully to obtain some insight into the cosmic scenario, we chose rac ‐Leu as a representative aliphatic amino acid substrate for the following reasons: (1) Enantiomerically enriched Leu has been found in carbonaceous meteorites,3a 2) VUV irradiation of a mixture of simple starting materials (H 2 O, CH 3 OH, CO 2 , CO, and NH 3 ) produces rac‐ Leu,10 and 3) Leu photodecomposes efficiently, at least at ambient temperatures 12. The photolysis of rac ‐Leu was performed in neutral and acidic water and ice media at temperatures ranging from 298 to 21 K to elucidate the effects of temperature and pH on the photoreaction mechanism of amino acids by using unpolarized UV light (214 nm) from a Y‐line lamp and circularly polarized synchrotron radiation (215 nm) from a polarizing undulator18a installed in the electron storage ring UVSOR‐II 18b…”

Section: Introductionmentioning

confidence: 99%

Photoreaction of rac‐Leucine in Ice by Circularly Polarized Synchrotron Radiation: Temperature‐Induced Mechanism Switching from Norrish Type II to Deamination

Nishino

Hosaka

Katoh

et al. 2013

Chemistry A European J

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The delivery of extraterrestrial organics to primitive Earth is considered to have triggered the origin and subsequent evolution of life. Indeed, enantiomerically enriched amino acids of nonterrestrial origin have been found in carbonaceous meteorites, and enantioselective photodecomposition by circularly polarized light (CPL) in outer space has been proposed to have played some role in the initial enantiomeric bias. To experimentally examine this possibility and elucidate the photoreaction mechanisms, we have studied the photolysis of racemic leucine (rac-Leu) in acidic and neutral ice/water media at 21-298 K with left- and right-CPL in an attempt to detect enantiomerically enriched D- and L-Leu, respectively. Comprehensive product analyses revealed that the CPL-induced deracemization of Leu proceeds in both acidic and neutral ice matrices even at 21 K, and that the main mechanism switches from Norrish-type II γ-hydrogen abstraction to SN i deamination on lowering the temperature. The potential role of the CPL-induced photodecomposition of amino acids as a source of the enantiomer imbalance in meteorites is discussed.

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New lattice for UVSOR

Cited by 13 publications

References 5 publications

Bayesian optimization of the dynamic aperture in UVSOR-IV design study

Bayesian optimization of the dynamic aperture in UVSOR-IV design study

Lattice design of the UVSOR-IV storage ring

Photoreaction of rac‐Leucine in Ice by Circularly Polarized Synchrotron Radiation: Temperature‐Induced Mechanism Switching from Norrish Type II to Deamination

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