During July, October, and February, users conducted initial tests with light from Jefferson Lab's IR Demo Free-Electron Laser (FEL). Basic science efforts have included first measurements of hydrogen defect lifetimes in bulk silicon (College of William and Mary, Vanderbilt), energy transfer mechanisms in proteins (R. Austin, Princeton), and generation of short-pulse (400 fs) x-rays (Jefferson Lab, University of Georgia). In addition, the third and fourth of six available user labs in the facility were commissioned to accommodate the first user tests for IR microscopy (Norfolk State University) and for atomic physics/chemical dynamics (University of Virginia, Old Dominion University). Applied science efforts have included high-rate, high-quality film deposition by pulsed laser deposition, and resonant polymer ablation in polyimides and polyamides -- both by users from William and Mary.
The kilowatt-scale, 2 to 8 micron, wavelength-tunable IR Demo FEL is driven by the same superconducting radio frequency technology used for Jefferson Lab's main nuclear physics mission. This supporting technology effort has multiple synergies with Jefferson Lab's planned CEBAF upgrade to 12 GeV.
The IR Demo FEL offers a unique pulse structure: sub-picosecond micropulses at high repetition rates of 18, 37, and 75 MHz -- short pulses ideal for manipulating materials-surface effects with high precision and for time-resolved studies. A Navy-funded upgrade now getting under way will widen the wavelength range to 0.25 to 14 microns by 2003, with 10 kW in the IR and the potential to deliver up to 1 kW in the UV.