抄録
Radioactive water was obtained using a laser-driven deuteron beam. A Ti:sapphire tabletop laser was
used to generate optical pulses with a peak power of 36 TW, a pulse duration of 30 fs, and a repetition
frequency of 10 Hz. The pulses were focused on a tape target to accelerate deuterons via laser-plasma
interaction. The deuterons were incident on nitrogen gas held in a gas chamber. Short-lived positron
emitters of 15O were created via a nuclear reaction of 14N (d, n)15O in the chamber and were carried to a
synthetic instrument. After laser irradiation for 180 s, we confi rmed activity of 1.2 ± 0.5 Bq in the form
of water molecules included in the liquid. To obtain radioactive water, we developed two main
experimental techniques: automatic adjustment of laser focusing in a vacuum environment; and image
evaluation of the spatial distribution of a deuteron beam.
