Recent Results & Plans For The Future On SLAC Damped Detuned Structures ( DDS )

The cells in the SLAC DDS are designed in such a way that the transverse modes excited by the beam are detuned in a Gaussian fashion so that destructive interference causes the wake function to decrease rapidly and smoothly. Moderate damping provided by four waveguide manifolds running along the outer wall of the accelerator is utilised to suppress the reappearance of the wake function at long ranges where the interference becomes constructive again. The newly developed spectral function method, involving a continuum of frequencies, is applied to analyze the wake function of the DDS 1 design and to study the dependence of the wake function on manifold termination. The wake function obtained with the actually realized manifold terminations is presented and compared to wake function measurements recently carried out at the ASSET facility installed in the SLAC LINAC. Paper presented at the 7 Workshop on Advanced Accelerator Concepts, Lake Tahoe, CA, October 13-19 1996 1 Supported by Department of Energy grant number DE-FG03-93ER40759 and DE-AC0376SF00515 Recent Results & Plans For The Future On SLAC Damped Detuned Structures (DDS) N.M. Kroll, R.M. Jones, C. Adolphsen , K.L.F. Bane, W.R. Fowkes, K. Ko, R.H. Miller, R.D. Ruth, M. Seidel, and J.W. Wang †Stanford Linear Accelerator Center, M/S 26, P.O Box 4349, Stanford, CA 94309 ‡ University of California, San Diego, La Jolla, CA 92093-0319 Abstract. The cells in the SLAC DDS are designed in such a way that the transverse modes excited by the beam are detuned in a Gaussian fashion so that destructive interference causes the wake function to decrease rapidly and smoothly. Moderate damping provided by four waveguide manifolds running along the outer wall of the accelerator is utilised to suppress the reappearance of the wake function at long ranges where the interference becomes constructive again. The newly developed spectral function method, involving a continuum of frequencies, is applied to analyze the wake function of the DDS 1 design and to study the dependence of the wake function on manifold termination. The wake function obtained with the actually realized manifold terminations is presented and compared to wake function measurements recently carried out at the ASSET facility installed in the SLAC LINAC. The cells in the SLAC DDS are designed in such a way that the transverse modes excited by the beam are detuned in a Gaussian fashion so that destructive interference causes the wake function to decrease rapidly and smoothly. Moderate damping provided by four waveguide manifolds running along the outer wall of the accelerator is utilised to suppress the reappearance of the wake function at long ranges where the interference becomes constructive again. The newly developed spectral function method, involving a continuum of frequencies, is applied to analyze the wake function of the DDS 1 design and to study the dependence of the wake function on manifold termination. The wake function obtained with the actually realized manifold terminations is presented and compared to wake function measurements recently carried out at the ASSET facility installed in the SLAC LINAC.