Speaker
Dr
Olaf Grulke
(MPI for Plasma Physics)
Description
A prototype high density helicon discharge is under development, which aims to demonstrate its feasibility as a plasma cell for advanced accelerator schemes as AWAKE. The discharge mechanisms relies on the non-resonant absorption of low-frequency plasma waves (with a frequency typically on the order of 10MHz), which are excited by antennas outside the vacuum chamber. The external wave excitation scheme allows for a distributed plasma generation without any obstacles within the beam path and thus, makes the plasma cell scalable to almost arbitrary lengths. In this paper results from the PROMETHEUS-A experiment are presented. The cell consists of a 1m long, 5cm diameter quarz vacuum tube embedded into a set of 4 water-cooled magnetic field coils, generating a homogenous magnetic field B<130mT. Helicon waves are excited by 4 individual helical antennas wrapped around the tube, which are energeized with a total peak rf power of 40kW at an rf frequency of 13.56 MHz. Unparalleled peak plasma densities compatible with AWAKE's nominal plasma density are achieved.
Primary author
Dr
Olaf Grulke
(MPI for Plasma Physics)
Co-author
Dr
Birger Buttenschoen
(MPI for Plasma Physics)
