High performance FEL for the proposed PEARL research platform

A consortium of Pacific Rim institutions is proposing to construct a sea-going facility based on a free electron laser lidar. Called PEARL, for Pan-Oceanic Environmental and Atmospheric Research Laboratory, the platform will be a powerful tool for atmospheric and marine research on topics involving the global environment and US and international security matters. Numerous security issues, and understanding the impact of human activities on the environment, require observing wide varieties of chemical compounds in situ and often at considerable range from the observer. Optical remote sensing, with instruments such as light detection and ranging (lidar) systems, have the potential for the necessary studies, but their performance has heretofore been restricted by low power and limited wavelength tunability. In contrast, the FEL for the PEARL platform will have continuous wavelength tunability from 250 nm to 20 mu m and the power to project beams over large ocean expanses or basin-sized land regions. This paper summarizes the principal features of the PEARL FEL, in the context of PEARL's missions. Directly descended from the MkIII, the PEARL FEL will incorporate highly-traceable developments including a photoinjector, high current linac, high power RF system, and several features to increase efficiency. The challenges of giving the mobility needed for environmental and defense remote sensing applications to an instrument as large and heavy as a FEL will be met by mounting the laser in a large ship. Using a former US Naval vessel and existing FEL and optical apparatus result in an estimated cost less than one-fourth that of all-new construction. (C) 1998 Elsevier Science B.V. All rights reserved.