1 STATUS OF THE LASER ELECTRON ACCELERATOR PROJECT * Tomas Plettner, R.L. Byer, M. Hennessy, Y.C Huang ** Edward Ginzton Labs, Stanford University, Stanford, CA 94305, USA J.E. Spencer, R.H. Siemann, H. Wiedemann Stanford Linear Accelerator Center, Stanford CA 94309, USA T.I. Smith, R.L. Swent, Hansen Experimental Physics Lab, Stanford University, Stanford, CA 94305, USA A major goal of the Laser Electron Accelerator Project (LEAP) is to perform an experiment that clearly demonstrates laser acceleration in a dielectric loaded vacuum. The experiment is being carried out at the SCA-FEL facility at Stanford University which provides a 30 MeV electron beam that has been propagated through the LEAP line successfully. The energy spectrometer has been calibrated, the laser transport line is near completion and the dielectric accelerator cell is being assembled. We expect to perform our first attempt to observe laser driven acceleration in the summer of 1998. The design of the experiment is discussed and the expected results are presented. 1 Introduction The subject of laser driven particle acceleration is an ideal example of a classical, quantum-mechanical wave-particle interaction that has generated considerable discussion ranging from its impossibility to its impracticality. Laser driven acceleration in a dielectric loaded vacuum has been discussed in detail in previous papers both for a single cell and for a high-energy accelerator. 1,2 In essence, the three important practical advantages of this scheme are the higher energy gradients that could be achieved compared to conventional RF linear accelerators, the absence of any material that could deteriorate the electron beam quality as in plasma based laser accelerators and the large-scale commercial developments in lasers and integrated circuit technology. 2 Some general Aspects of Particle Acceleration Because a free, charged particle can’t absorb without emission, it should radiate when scattered or accelerated. This suggests a range of peripheral processes that need to be considered when an electron passes through an accelerator cavity or set of boundary conditions such as implied by the Lawson theorem 3 or its variants. Because this is essentially true of any cavity regardless of acceleration, accelerator structure design is important especially at limiting apertures such as the accelerating cavities and their irises. Schwinger was the first one to clearly understand the limitations this imposed on the attainable energy. 4 * Supported by U.S. Department of Energy, contracts DE-FG03-97ER41043 & DE-AC03- 76SF00515. ** Now at National Tsinghua University, Hsinchu, Taiwan 30043.