RIKEN Atomic, Molecular & Optical Physics Laboratory

2023

• “Doppler-free Spectroscopy of Buffer-Gas-Cooled Calcium Monohydroxide”
  Yuki Miyamoto, Reo Tobaru, Yuiki Takahashi, Ayami Hiramoto, Kana Iwakuni, Susumu Kuma, Katsunari Enomoto, and Masaaki Baba
  J. Phys. Chem. A XXXX, XXX, XXX-XXX (2023)
  

2022

• “High-resolution spectroscopy of buffer-gas-cooled phthalocyanine”
  Yuki Miyamoto, Reo Tobaru, Yuiki Takahashi, Ayami Hiramoto, Kana Iwakuni, Susumu Kuma, Katsunari Enomoto & Masaaki Baba
  Commun. Chem. 5, 161 (2022)
  

• “Absolute Energy Measurements with Superconducting Transition-Edge Sensors for Muonic X-ray Spectroscopy at 44 keV”
  Daikang Yan, Joel C. Weber, Tejas Guruswamy, Kelsey M. Morgan, Galen C. O’Neil, Abigail L. Wessels, Douglas A. Bennett, Christine G. Pappas, John A. Mates, Johnathon D. Gard, Daniel T. Becker, Joseph W. Fowler, Daniel S. Swetz, Daniel R. Schmidt, Joel N. Ullom, Takuma Okumura, Tadaaki Isobe, Toshiyuki Azuma, Shinji Okada, Shinya Yamada, Tadashi Hashimoto, Orlando Quaranta, Antonino Miceli, Lisa M. Gades, Umeshkumar M. Patel, Nancy Paul, Guojie Bian & Paul Indelicato
  J. Low Temp. Phys.　209,　271 (2022)
  

2021

• “IR-photon quenching of delayed electron detachment from hot pentacene anions”
  S. Iida, S. Kuma, M. Kuriyama, T. Furukawa, M. Kusunoki, H. Tanuma, K. Hansen, H. Shiromaru, and T. Azuma
  Phys. Rev. A 104, 043114 (2021)
  Selected as Editors’ Suggestion
  

• “Deexcitation Dynamics of Muonic Atoms Revealed by High-Precision Spectroscopy of Electronic K X rays”
  T. Okumura, T. Azuma, D. A. Bennett, P. Caradonna, I. Chiu, W. B. Doriese, M. S. Durkin, J. W. Fowler, J. D. Gard, T. Hashimoto, R. Hayakawa, G. C. Hilton, Y. Ichinohe, P. Indelicato, T. Isobe, S. Kanda, D. Kato, M. Katsuragawa, N. Kawamura, Y. Kino, M. K. Kubo, K. Mine, Y. Miyake, K. M. Morgan, K. Ninomiya, H. Noda, G. C. O’Neil, S. Okada, K. Okutsu, T. Osawa, N. Paul, C. D. Reintsema, D. R. Schmidt, K. Shimomura, P. Strasser, H. Suda, D. S. Swetz, T. Takahashi, S. Takeda, S. Takeshita, M. Tampo, H. Tatsuno, X. M. Tong, Y. Ueno, J. N. Ullom, S. Watanabe, and S. Yamada
  Phys. Rev. Lett. 127, 053001 (2021)
  Selected as Editors’ Suggestion
  Press release (in Japanese) here

• “Dynamical Response of Transition-Edge Sensor Microcalorimeters to a Pulsed Charged-Particle Beam”
  Takuma Okumura, Toshiyuki Azuma, Douglas A. Bennett, Pietro Caradonna, I-Huan Chiu, W. Bertrand Doriese, Malcolm S. Durkin, Joseph W. Fowler, Johnathon D. Gard, Tadashi Hashimoto, Ryota Hayakawa, Gene C. Hilton, Yuto Ichinohe, Paul Indelicato, Tadaaki Isobe, Sohtaro Kanda, Miho Katsuragawa, Naritoshi Kawamura, Yasushi Kino, Kairi Mine, Yasuhiro Miyake, Kelsey M. Morgan, Kazuhiko Ninomiya, Hirofumi Noda, Galen C. O’Neil, Shinji Okada, Kenichi Okutsu, Takahito Osawa, Nancy Paul, Carl D. Reintsema, Dan R. Schmidt, Koichiro Shimomura, Patrick Strasser, Hirotaka Suda, Daniel S. Swetz, Tadayuki Takahashi, Shinichiro Takeda, Soshi Takeshita, Hideyuki Tatsuno, Yasuhiro Ueno, Joel N. Ullom, Shin Watanabe, Shinya Yamada
  in IEEE Transactions on Applied Superconductivity, 31, 5, 1, 2101704 (2021)
  

• “Electronic spectroscopy of Mg-phthalocyanine embedded in cold hydrogen clusters produced by a pulsed nozzle”
  Hatsuki Otani, Hiroko Nakahara, Haruka Goto, Susumu Kuma, and Takamasa Momose
  J. Chem. Phys. 155, 044309 (2021)
  

• “Prospect for Precision Measurement of the Yb2+ 1S0–3P0o Transition Frequency”
  Naoki Kimura and Masatoshi Kajita
  J. Phys. Soc. Jpn. 90, 064302 (2021)
  

• “Testing Quantum Electrodynamics with Exotic Atoms”
  Nancy Paul, Guojie Bian, Toshiyuki Azuma, Shinji Okada, and Paul Indelicato
  Phys. Rev. Lett. 126, 173001 (2021)
  

• “Status of the Laser Spectroscopy and Merged-beam Experiments at RICE”
  Y. Nakano, R. Igosawa, S. Iida, S. Okada, M. Lindley, S. Menk, R. Nagaoka, T. Hashimoto, S. Yamada, T. Yamaguchi, S. Kuma, and T. Azuma
  JPS Conf. Proc. 35, 011006 (2021)
  

• “Transition-Edge Sensor Optimization for Hard X-ray Applications”
  D. Yan, J. C. Weber, K. M. Morgan, A. L. Wessels, D. A. Bennett, C. G. Pappas, J. A. Mates, J. D. Gard, D. T. Becker, J. W. Fowler, D. S. Swetz, D. R. Schmidt, J. N. Ullom, T. Okumura, T. Isobe, T. Azuma, S. Yamada, S. Okada, T. Hashimoto, N. Paul, G. Bian and P. Indelicato
  in IEEE Transactions on Applied Superconductivity, 31, 5, 1, 2100505 (2021)
  

• “Broadband high-energy resolution hard x-ray spectroscopy using transition edge sensors at SPring-8”
  Shinya Yamada, Yuto Ichinohe, Hideyuki Tatsuno, Ryota Hayakawa, Hirotaka Suda, Takaya Ohashi, Yoshitaka Ishisaki, Tomoya Uruga, Oki Sekizawa, Kiyofumi Nitta, Yoshio Takahashi, Takaaki Itai, Hiroki Suga, Makoto Nagasawa, Masato Tanaka, Minako Kurisu, Tadashi Hashimoto, Douglas Bennett, Ed Denison, William Bertrand Doriese, Malcolm Durkin, Joseph Fowler, Galen O’Neil, Kelsey Morgan, Dan Schmidt, Daniel Swetz, Joel Ullom, Leila Vale, Shinji Okada, Takuma Okumura, Toshiyuki Azuma, Toru Tamagawa, Tadaaki Isobe, Satoshi Kohjiro, Hirofumi Noda, Keigo Tanaka, Akimichi Taguchi, Yuki Imai, Kosuke Sato, Tasuku Hayashi, Teruhiko Kashiwabara, and Kohei Sakata
  Rev. Sci. Instrum. 92, 013103 (2021)
  Press release (in Japanese) here

2020

• “State-Selective Observation of Radiative Cooling of Vibrationally Excited C₂^– “
  S. Iida, S. Kuma, H. Tanuma, T. Azuma, and H. Shiromaru
  J. Phys. Chem. Lett. 11(24), 10526–10531 (2020)

• “Photodissociation spectroscopy of N₂O⁺ in the ion storage ring RICE”
  R. Igosawa, A. Hirota, N. Kimura, S. Kuma, K. C. Chartkunchand, P. M. Mishra, M. Lindley, T. Yamaguchi, Y. Nakano, and T. Azuma
  J. Chem. Phys. 153, 184305 (2020)

• “Prospect for Vibrational Transition Frequency Measurement of Rare-gas Hydride Ions”
  Masatoshi Kajita and Naoki Kimura
  J. Phys. Soc. Jpn. 89, 114301 (2020)

• “5p-4f level crossing in palladium-like ions and its effect on metastable states”
  Naoki Kimura, Ryunosuke Kodama, Priti, Naoki Numadate, Kento Suzuki, Masashi Monobe, and Nobuyuki Nakamura
  Phys. Rev. A 102, 032807 (2020)

• “Radiative cooling dynamics of isolated N₂O⁺ ions in a cryogenic electrostatic ion storage ring”
  A. Hirota, R. Igosawa, N. Kimura, S. Kuma, K. C. Chartkunchand, P. M. Mishra, M. Lindley, T. Yamaguchi, Y. Nakano, and T. Azuma
  Phys. Rev. A 102, 023119 (2020)

• “Threshold Photodetachment Spectroscopy of the Positronium Negative Ion”
  Koji Michishio, Susumu Kuma, Yugo Nagata, Luca Chiari, Taro Iizuka, Riki Mikami, Toshiyuki Azuma, and Yasuyuki Nagashima
  Phys. Rev. Lett. 125, 063001 (2020)

• “X-ray Spectroscopy of Muonic Atoms Isolated in Vacuum with Transition Edge Sensors”
  S. Okada, T. Azuma, D. A. Bennett, P. Caradonna, W. B. Doriese, M. S. Durkin, J. W. Fowler, J. D. Gard, T. Hashimoto, R. Hayakawa, G. C. Hilton, Y. Ichinohe, P. Indelicato, T. Isobe, S. Kanda, M. Katsuragawa, N. Kawamura, Y. Kino, Y. Miyake, K. M. Morgan, K. Ninomiya, H. Noda, G. C. O’Neil, T. Okumura, C. D. Reintsema, D. R. Schmidt, K. Shimomura, P. Strasser, D. S. Swetz, T. Takahashi, S. Takeda, S. Takeshita, H. Tatsuno, Y. Ueno, J. N. Ullom, S. Watanabe and S. Yamada
  J. Low Temp. Phys. (2020) DOI: 10.1007/s10909-020-02476-5

• “Rotationally Resolved Excitation Spectra Measured by Slow Electron Detachment from Si₂^–“
  Shimpei Iida, Susumu Kuma, Jun Matsumoto, Takeshi Furukawa, Hajime Tanuma, Toshiyuki Azuma, Haruo Shiromaru, Vitali Zhaunerchyk, and Klavs Hansen
  J. Phys. Chem. Lett. 11(13), 5199–5203 (2020)

• “Prospects in rare-gas hydride ions for terahertz frequency standards”
  Masatoshi Kajita and Naoki Kimura
  J. Phys. B: At. Mol. Opt. Phys. 53 135401 (2020)

2019

• “Radiative cooling of cationic carbon clusters, C_N⁺, N = 8, 10, 13–16″
  F.-Q. Chen, N. Kono, R. Suzuki, T. Furukawa, H. Tanuma, P. Ferrari, T. Azuma, J. Matsumoto, H. Shiromaru, V. Zhaunerchyk, and K. Hansen
  Phys. Chem. Chem. Phys. 21, 1587 (2019)

• “Impact of a hydrophobic ion on the early stage of atmospheric aerosol formation”
  Linda Feketeová, Paul Bertier, Thibaud Salbaing, Toshiyuki Azuma, Florent Calvo, Bernadette Farizon, Michel Farizon, and Tilmann D. Märk
  PNAS, 116(45), 22540-22544 (2019)

• “Roadmap on photonic, electronic and atomic collision physics: III. Heavy particles: with zero to relativistic speeds”
  Friedrich Aumayr, Kiyoshi Ueda, Emma Sokell, Stefan Schippers, HosseinSadeghpour, Frédéric Merkt, Thomas F Gallagher, F Barry Dunning, Paul Scheier, Olof Echt, Tom Kirchner, Stephan Fritzsche, Andrey Surzhykov, Xinwen Ma, Roberto Rivarola, Omar Fojon, Lokesh Tribedi, Emily Lamour, José R Crespo López-Urrutia, Yuri A Litvinov, Vladimir Shabaev, Henrik Cederquist, Henning Zettergren, Marika Schleberger, Richard A Wilhelm, Toshiyuki Azuma, Philippe Boduch, Henning T Schmidt, and Thomas Stöhlker
  J. Phys. B52, 171003 (2019)

• 「HIMACが切り拓いた高エネルギーイオン原子衝突の最前線」
  東 俊行
  RADIOISOTOPES, 68, 483–487 (2019)

• 「数百 MeV/u重イオンと固体標的—X線および二次電子放出—」
  東 俊行、小牧 研一郎
  RADIOISOTOPES, 68, 489–499 (2019)

• 「数百MeV/u重イオンと結晶標的I—2次元コヒーレント共鳴励起—」
  東 俊行、中野 祐司
  RADIOISOTOPES, 68, 501–515 (2019)

• 「数百 MeV/u重イオンと結晶標的II—3次元コヒーレント共鳴励起—」
  中野 祐司、東 俊行
  RADIOISOTOPES, 68, 517–528 (2019)

2018

• “A cryogenic linear ion trap beamline for providing keV ion bunches”
  S. Menk, P. Bertier, Y. Enomoto, T. Masunaga, T. Majima, Y. Nakano, and T. Azuma
  Rev. Sci. Instr. 89, 113110 (2018)

• “Electronic and vibrational radiative cooling of the small carbon clusters C₄^– and C₆^–“
  N. Kono, R. Suzuki, T. Furukawa, J. Matsumoto, H. Tanuma, H. Shiromaru, T. Azuma, and K. Hansen
  Phys. Rev. A 98, 063434 (2018)


• “Superfluorescence, Free-Induction Decay, and Four-Wave Mixing: Propagation of Free-Electron Laser Pulses through a Dense Sample of Helium Ions”
  J. R. Harries, H. Iwayama, S. Kuma, M. Iizawa, N. Suzuki, Y. Azuma, I. Inoue, S. Owada, T. Togashi, K. Tono, M. Yabashi, and E. Shigemasa
  Phys. Rev. Lett. 121, 263201 (2018)
  Press release (in Japanese) here

2017

• “Pulsed beam of extremely large helium droplets”
  S. Kuma and T. Azuma
  Cryogenics 88, 78 (2017)
•  
• “Design and commissioning of the RIKEN cryogenic electrostatic ring (RICE)”
  Y. Nakano, Y. Enomoto, T. Masunaga, S. Menk, P. Bertier, and T. Azuma
  Rev. Sci. Instrum. 88, 033110 (2017)
•  

2016

• 「コヒーレント共鳴励起による多価イオンの精密分光」
  中野 祐司、東 俊行
  原子衝突学会誌 しょうとつ 13(6), 117-125 (2016)　
•  
• “Detection of Recurrent Fluorescence Photons”
  Y. Ebara, T. Furukawa, J. Matsumoto, H. Tanuma, T. Azuma, H. Shiromaru, and K. Hansen
  Phys. Rev. Lett. 117, 133004 (2016)
  Press release (in Japanese) here
•  
• “Observation of a shape resonance of the positronium negative ion”
  K. Michishio, T. Kanai, S. Kuma, T. Azuma, K. Wada, I. Mochizuki, T. Hyodo, A. Yagishita and Y. Nagashima
  Nature Communications 7, 11060 (2016)
  Press release (in Japanese) here
•  

2015

• “Inverse internal conversion in C₄? below the electron detachment threshold”
  N. Kono, T. Furukawa, H. Tanuma, J. Matsumoto, H. Shiromaru, T. Azuma, K. Najafian, M. S. Pettersson, B. Dynefors and K. Hansen
  Phys. Chem. Chem. Phys. 17, 24732 (2015)
•  
• “Metastable Ar¹⁷⁺ (2s) production by Stark-assisted resonant coherent excitation”
  Y. Nakano, A. A. Sokolik, A. V. Stysin, Y. Nakai, K. Komaki, E. Takada, T. Murakami and T. Azuma
  J. Phys. B: At. Mol. Opt. Phys. 48 144026 (2015)
  Selected as an featured article in LabTalk
•  
• “Cooling dynamics of photo-excited negative carbon cluster ions stored in an ion storage ring”
  T. Furukawa, G. Ito, M. Goto, T. Majima, H. Tanuma, J. Matsumoto, H. Shiromaru, K. Hansen and T. Azuma
  Nucl. Instrum. Methods Phys. Res., Sect. B 354, 192 (2015)
•  
• “A streak camera study of superfluorescence at multiple wavelengths from helium atoms excited using free electron laser pulses”
  J. R. Harries, H. Iwayama, M. Nagasono, T. Togashi, M. Yabashi, S. Kuma, K. Nakajima, Y. Miyamoto, C. Ohae, N. Sasao and E. Shigemasa
  J. Phys. B: At. Mol. Opt. Phys. 48 105002 (2015) Erratum
•  
• “Simultaneous Measurements of Super-Radiance at Multiple Wavelengths from Helium Excited States: I. Experiment”
  K. Nakajima, J. R. Harries, H. Iwayama, S. Kuma, Y. Miyamoto, M. Nagasono, C. Ohae, T. Togashi, M. Yabashi, E. Shigemasa and N. Sasao
  J. Phys. Soc. Jpn. 84, 054301 (2015)
•  

2014

• “Cooling dynamics of photo-excited C₆^– and C₆H^–“
  G. Ito, T. Furukawa, H. Tanuma, J. Matsumoto, H. Shiromaru, T. Majima, M. Goto, T. Azuma, and K. Hansen
  Phys. Rev. Lett. 112, 183001 (2014)
•  
• “Radiative cooling of C₇^–“
  K. Najafian, M.S. Pettersson, B. Dynefors, H. Shiromaru, J. Matsumoto, H. Tanuma, T. Furukawa, T. Azuma, K. Hansen
  J. Chem. Phys. 140, 104311 (2014)
•  

2013

• “Effects of fine structure depolarization studied by resonant coherent excitation of H-like Ar17+”
  Y. Nakano, A. Hatakeyama, Y. Nakai, K. Komaki, E. Takada, T. Murakami,
  T. Azuma,
  Phys. Scr. T156, 014061 (2013)
•  
• “Stark effect in resonant coherent excitation of 2s electron of Li-like Fe²³⁺ ions channeling in a Si crystal”
  Y. Nakai, Y. Nakano, T. Ikeda, Y. Kanai, T. Kambara, N. Fukunishi, C. Kondo, T. Azuma, K. Komaki, Y. Yamazaki
  Nucl. Instr. Meth. B 315 (2013) 94
•  
• “Direct observation of internal energy distributions of C₅^–“
  M. Goto, A.E.K. Sundén, H. Shiromaru, J. Matsumoto, H. Tanuma, T. Azuma, and K. Hansen
  J. Chem. Phys. 139, 054306 (2013)
•  
• “Resonant coherent excitation of the lithiumlike uranium ion: A scheme for heavy-ion spectroscopy”
  Y. Nakano, Y. Takano, T. Ikeda, Y. Kanai, S. Suda, T. Azuma, H. Bräuning, A. Bräuning-Demian, D. Dauvergne, Th. Stöhlker, and Y. Yamazaki
  Phys. Rev. A (Rapid Comm.) 87, 060501R (2013)
•  

2012

• “Generation of Highly Phase-Matched Isolated Attosecond Pulses Using Multi-mJ, Carrier-Envelope Phase Stabilized, Few-Cycle Laser Pulses”
  T. Kanai, Y. Fu, Y. Kamba, S. Bohman, H. Yoshida, T. Kanai, S. Yamaguchi, E. J. Takahashi, Y. Nabekawa, A. Suda, and K. Midorikawa
  Multiphoton Processes and Attosecond Physics, Springer Proceedings in Physics 125, 105 (2012)
•  
• “Development of High Power Infrared Optical Parametric Amplification Laser System Seeded by Self-difference Frequency Generation Pulses”
  T. Kanai, S. Weber, A. Zair, C. Hutchison, T. Siegel, M. Oppermann, S. Hutchinson, T. Witting, L. Brugnera, R. A. Ganeev, T. Azuma, K. Midorikawa, and J. P. Marangos
  Multiphoton Processes and Attosecond Physics, Springer Proceedings in Physics 125, 45 (2012)
•  
• “Anionic Polymerization Mechanism of Acrylonitrile Trimer Anions: Key Branching Point between Cyclization and Chain Propagation”
  Keijiro Ohshimo, Yoshiya Inokuchi, Takayuki Ebata, Koichi Ohno
  J. Phys. Chem. A, 116(30), 7937-7942 (2012)
•  
• “Ionization of naphthalene via the Rydberg states using a femtosecond 775 nm pulse”
  M. Goto, K. Hansen
  Chem. Phys. Lett. 522, 23-27 (2012)
•  
• “Selective production of the doubly excited 2p² (¹D) state in He-like Ar¹⁶⁺ ions by resonant coherent excitation”
  Y. Nakano, S. Suda, A. Hatakeyama, Y. Nakai, K. Komaki, E. Takada, T. Murakami, T. Azuma
  Phys. Rev. A 85, 020701(R) (2012)
•  

2011

• “Harmonic Generation in Mixed Gases and Its Application to Attosecond Physics”
  T. Kanai, E. J. Takahashi, Y. Nabekawa, K. Midorikawa
  Jpn. J. Optics, 40(3), 136-141 (2011). (in Japanese)
•  
• “Observation of intrashell radiative decay of Li-like uranium (2p_3/2-2s_1/2) using silicon drift detectors”
  Y. Nakano, Y. Takano, T. Shindo, T. Ikeda, Y. Kanai, S. Suda, T. Azuma, H. Bräuning, A. Bräuning-Demian, Th. Stöhlker, D. Dauvergne, Y. Yamazaki
  Phys. Scr. T144, 014010 (2011)
•  
• “Electron emission from fast heavy ions associated with resonant coherent excitation”
  S. Suda, Y. Nakano, K. Metoki, T. Azuma, Y. Takano, A. Hatakeyama, Y. Nakai, K. Komaki, E. Takada, T. Murakami
  Phys. Scr. T144, 014044 (2011)
•  
• “Microhydration of the methylene blue cation in an electrospray ion source”
  T. Sato, T. Majima, Kenro Hashimoto, Kouhei Hashimoto, Y. Zama, J. Matsumoto, H. Shiromaru, K. Okuno, H. Tanuma, T. Azuma
  Eur. Phys. J. D 63, 189-194 (2011)
•  

2009

• “Absolute Cooling Rates of Freely Decaying Fullerenes”
  A. E. K. Sundén, M. Goto, J. Matsumoto, H. Shiromaru, H. Tanuma, T. Azuma, J.U. Andersen, S. E. Canton, K. Hansen
  Phys. Rev. Lett. 103, 143001 (2009)
•  
• “Polarization Control in Three-dimensional Resonant Coherent Excitation”
  Y. Nakano, C. Kondo, A. Hatakeyama, Y. Nakai, T. Azuma, K. Komaki, Y. Yamazaki, E. Takada and T. Murakami
  Phys. Rev. Lett. 102, 085502 (2009)
•  
• “Resonant Coherent Excitation of Li-like Ar¹⁵⁺ Ions in a Thin Si Crystal”
  Y. Nakano, T. Inoue, T. Azuma, A. Hatakeyama, Y. Nakai, K. Komaki, Y. Yamazaki, E. Takada, T. Murakami
  J. Phys. Conf. 163, 012094 (2009)
•