Abstract

The concept of using nuclear energy to pump a laser by fission fragments of uranium can potentially be used to create large high power lasers that cannot be matched by other laser svstems[1]. That is possible owing to a high energy capacity of fission reactor and high penetration ability of neutrons in uranium multiplication systems. In the framework of designing of Energy Model of a Pulse Nuclear Reactor Pumped Laser System in IPPE[1] it was performed lasing experiments on ²³⁵U fission fragments pumping of 5d-6p atomic xenon 1.73 µm transition with 2 core fast burst reactor BARS-6 as a neutron source. The laser cell is a thin wall stainless steel tube 49 mm outer diameter and 400 mm lenth with internal 2.7 mg/cm^{2 235}UO₂ coating and filled Ar-Xe mixture (200: l) at 380 Torr. The laser cavity was formed by 6 m radius gold mirror and flat dielectric output coupler with reflectivity of 95% at 1.73 µm. The laser cell was surrounded by the 5 cm thick poliethylen moderator. In Fig. 1 thermal neutrons and laser output signal are shown. Thermal neutrons fluence was measured using Au radioactive indicator and was 1.7·10¹² n/cm². In Fig. 2 results of "master oscillator - two round trip amplifier" experiment are shown. As amplifier it was used a similar tube filled Ar-Xe mixture 2500 mm length with internal 5 µm thickness metal ²³⁵U coating and with optical windows. The energy gain in amplifier tube was ~ 4.

© 1996 IEEE