Simultaneous Measurements of Super-Radiance at Multiple Wavelengths from Helium Excited States: I. Experiment

  title={Simultaneous Measurements of Super-Radiance at Multiple Wavelengths from Helium Excited States: I. Experiment},
  author={K. Nakajima and James R Harries and Hiroshi Iwayama and Susumu Kuma and Yuki Miyamoto and Mitsuru Nagasono and Chiaki Ohae and Tadashi Togashi and Makina Yabashi and Eiji Shigemasa and Noboru Sasao},
  journal={Journal of the Physical Society of Japan},
In this paper, we report the results of measurements of the intensities and delays of super-radiance decays from excited helium atoms at multiple wavelengths. The experiment was performed using extreme ultraviolet radiation produced by the free electron laser at the SPring-8 Compact SASE Source test accelerator facility as an excitation source. We observed super-radiant transitions on the 1s3p → 1s2s (λ = 502 nm), 1s3d → 1s2p (λ = 668 nm), and 1s3s → 1s2p (λ = 728 nm) transitions. The pulse… 
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