The Pacific Northwest National Lab, Brookhaven National Lab, and a commercial accelerator design company, the Brookhaven Technology Group, have teamed to develop a device that produces subpicosecond pulses of high-energy electrons. This electron accelerator is unique in its compact size and use of advanced acceleration principles. It is expected that this enabling technology will have applications in accelerator research and the development of linear colliders and free electron lasers. In addition, applications are expected in cellular biology, molecular science, materials science, and the study of transient phenomena in the subnanosecond timeframe.
The accelerator is shown in the photograph below. The device generates an electron beam of extremely high brightness approaching 1016 A/m2 rad2, which is two orders of magnitude greater than the currently available value of approximately 1014 A/m2 rad2. The key advancement in the development of this 5 MeV accelerator was the achievement of a very high accelerating field gradient of 1 GV/m. A fast pulsed laser triggers the electron pulses by irradiating the cathode of the accelerator. The generated electrons are accelerated to relativistic velocities within 1 mm of the cathode, and these electrons can then be used to produce x-ray pulses that are useful for many of the studies mentioned earlier.
The generation and acceleration of high-brightness electron beams is an important step in the development of next-generation synchrotron light sources. This electron gun may enable the production of an accelerator-based, pulsed, ultra-violet/vacuum ultra-violet radiation source with applications in combustion dynamics, atmospheric science, biological science, and material science.
The successful development of this laser-excited, 5-MeV pulsed-electron gun resulted from the collaborative work of Triveni Srinivasan-Rao of the Brookhaven National Lab, Joseph C. McDonald of the Pacific Northwest National Lab, and J. Paul Farrell of the Brookhaven Technology Group.
References
Batchelor, K., Farrell, J.P., Conde, R., Srinivasan-Rao, T. and Smedley, J. "A Laser Triggered Synchronizable, Sub-Nanosecond Pulsed Electron Source," Proc. Intl. Conf. On Future Accelerators, Stony Brook, NY, June 2001 (to be published).
Farrell, J.P., Batchelor, K., Dudnikov, V., Srinivasan-Rao, T., Smedley, J., and McDonald, J. Laser Triggered Synchronizable X-Ray System for Real Time Study of Shock Waves in Condensed Materials.
Farrell, J.P., Batchelor, K., Meshkovsky, I., Pavlishin, I., Lekomtsev, V., Dyublov, A., Inochkin, M., and Srinivasan-Rao, T. A Sub-Picosecond Pulsed 5 MeV Electron Beam System.
Photograph of 5-MeV pulsed power supply and electron gun. The anode and vacuum enclosure, normally in place at the end of the tubular accelerating assembly (left side of photo), has been removed to show the carefully shaped cathode insulator assembly (pink-colored cone). The device is compact, with dimensions of approximately 2.5-m long, 1.2-m high, and 1-m high.