Speaker
Prof.
Patric Muggli
(Max-Planck-Institut für Physik)
Description
We have successfully demonstrated the driving of plasma wakefield by a square current profile electron bunch for the seeding for self-modulation instability (SMI) with 50pC bunches at the BNL-ATF. The experimental data is in excellent agreement with linear theory and OSIRIS-2D [1] simulation results [2]. Acquiring these results was possible because with low 50pC charge, the SMI does not grow within the 2cm propagation distance in the plasma. We explore here the possibility of identifying SMI growth experimentally with 1nC bunch by measuring the maximum energy gain/loss at plasma exit. According to linear theory, the initial wakefield amplitude is 20 times higher for a 1nC than than for a 50pC bunch, and this has been confirmed by the previous simulations [3]. Simulations also show that the SMI of the 1nC bunch grows significantly and reaches saturation over the 2cm propagation distance. Therefore, we further analyze the simulation results of 1nC bunch to examine the possibility of measuring the energy spectrum experimentally to confirm the development of SMI. Initial results show that due to dephasing between the bunch particles and the wakefields, the actual energy gain/loss by drive bunch particles is much lower than previously estimated.
Primary author
Ms
Yun Fang
(University of Southern California, Los Angeles)
Co-authors
Dr
Jorge Vieira
(Instituto Superior Tecnico)
Prof.
Patric Muggli
(Max-Planck-Institut für Physik)
Prof.
Warren Mori
(University of California, Los Angeles)
