Jerry M. Watson

Energy recovery in the Los Alamos free electron laser

Abstract Experiments to demonstrate recovery in conjunction with the Los Alamos free electron laser are reported in this paper. Deceleration of the electron beam greater than 70% has been observed. Beam transport through the system down to 3.5 MeV has been obtained and power flow measurements have been made that demonstrate the conversion of beam energy back into rf power. The resonant bridge couplers appear to function as designed. Predicted instabilities in the beam transport system have been observed.

The Los Alamos High-Brightness Accelerator FEL (HIBAF) facility☆

The 10 μm Los Alamos free-electron laser (FEL) facility is being upgraded. The conventional electron gun and bunchers have been replaced with a much more compact, 6 MeV photoinjector accelerator. By adding existing parts from previous experiments, the primary beam energy will be doubled to 40 MeV. With the existing 1 m wiggler (λw = 2.7 cm) and resonator, the facility can produce photons with wavelengths from 3 to 100 μm when lasing on the fundamental mode and produce photons in the visible spectrum with short-period wigglers or harmonic operation. After installation of a 150° bend, a second wiggler will be added as an amplifier. The installation of laser transport tubes between the accelerator vault and an upstairs laboratory will provide experimenters with a radiation-free environment for experiments. Although the initial experimental program of the upgraded facility will be to test the single-accelerator master-oscillator/power amplifier configuration, some portion of the operational time of the facility can be dedicated to user experiments.

Status of the Los Alamos free electron laser

Since the initial oscillator experiments were completed last year, the Los Alamos FEL has undergone some major modifications and additions in preparation for the next set of experiments. The laser performance is projected to be substantially enhanced, the rf energy-recovery technique will be demonstrated, and FEL physics measurements will be expanded. The accelerator is now being tuned with very promising performance. The above experiments will be completed during the next year.

First direct observation of FEL lasing from λ = 20 to 45 μm☆

Abstract In recent experiments at Los Alamos, we directly observed for the first time free-electron-laser (FEL) fundamental wavelengths from 20 to 45 μm. Our 1988 facilitys demonstrated wavelength span now extends from 9 to 45 μm. Upgrades are in progress to increase this span. This wavelength region uniquely complements existing FEL applications facilities.

The Los Alamos Free-Electron Laser Oscillator Experiment: Plans And Present Status

Plans have been made to modify the Los Almos free-electron laser amplifier experiment to allow its use as an oscillator at 10.6 microns. Several major changes were required, all of which have now been completed. The necessity for these changes is discussed as are the details of their fulfillment. In some cases we have progressed to the point where we can report on the performance of the new systems. The present status is described.

Proposed extended tuning range for the Los Alamos mid-infrared adjustable, coherent light experiment (miracle) facility

The Los Alamos Free-Electron Laser (FEL) Facility has been in operation as an oscillator in the 10..mu..m wavelength regime since 1983. Operations from 10 to 45..mu..m have been recently demonstrated which would provide a new applications capability: A Mid-Infrared Adjustable Coherent Light Experiment (MIRACLE) Facility. We propose to extend this tunability from 3 to 160..mu..m by upgrading the injector, accelerator, and resonator cavity. Potential applications in material science (high-temperature superconductors) and biophysics (DNA spectroscopy) for this wavelength regime are briefly addressed. 7 refs., 2 figs., 2 tabs.