Optimizing Beam Transport in Rapidly Compressing Beams on the Neutralized Drift Compression Experiment - II
Abstract
The Neutralized Drift Compression Experiment-II (NDCX-II) is an induction linac that generates intense pulses of 1.2 MeV helium ions for heating matter to extreme conditions. Here, we present recent results on optimizing beam transport. The NDCX-II beamline includes a 1-meter-long drift section downstream of the last transport solenoid, which is filled with charge-neutralizing plasma that enables rapid longitudinal compression of an intense ion beam against space-charge forces. The transport section on NDCX-II consists of 28 solenoids. Finding optimal field settings for a group of solenoids requires knowledge of the envelope parameters of the beam. Imaging the beam on scintillator gives the radius of the beam, but the envelope angle dr/dz is not measured directly. We demonstrate how the parameters of the beam envelope (r, dr/dz, and emittance) can be reconstructed from a series of images taken at varying B-field strengths of a solenoid upstream of the scintillator. We use this technique to evaluate emittance at several points in the NDCX-II beamline and for optimizing the trajectory of the beam at the entry of the plasma-filled drift section.
Cite
@article{arxiv.1711.00539,
title = {Optimizing Beam Transport in Rapidly Compressing Beams on the Neutralized Drift Compression Experiment - II},
author = {Anton D. Stepanov and Erik P. Gilson and Igor D. Kaganovich and Peter A. Seidl and Arun Persaud and Qing Ji and Thomas Schenkel and Alex Friedman and John J. Barnard and David P. Grote},
journal= {arXiv preprint arXiv:1711.00539},
year = {2017}
}