Repetitive production of positron emitters using deuterons accelerated by multiterawatt laser pulses

Positron emitters (11)C, (13)N, and (15)O, which can be used in positron emission tomography, were produced using deuterons accelerated by irradiation of laser pulses approximately 70 TW in peak power and approximately 30 fs in duration with a repetition of 10 Hz during a period of as long as 200 s. Every laser pulse irradiates the fresh surface of a long strip of a solid-state thin film. Deuterons contained in the film are accelerated in the relativistic plasma induced by the pulse. The deuterons are repetitively incident on solid plates, which are placed near the film, to produce positron emitters by nuclear reactions. The radioactivities of the activated plates are measured after the termination of laser irradiation. In activation of graphite, boron-nitride, and melamine plates, the products had total activities of 64, 46, and 153 Bq, respectively. Contamination in the setup was negligible even after several thousands of laser shots. Our apparatus is expected to greatly contribute to the construction of a compact PET diagnostic system in the future.