HESQ, a low energy beam transport

In this paper Helical Electrostatic Quadrupole (HESQ) channel is suggested for low energy beam transport of H− beams from ion source to the RFQ. Being an electrostatic focusing lens, the HESQ avoids neutralization time. The HESQ lenses provide stronger first‐order focusing in contrast to weak second‐order focusing of einzel lenses and is also stronger in focusing than the alternating gradient focusing. In this paper, we will present analytical formalism for such channel and results of PIC simulation with space charge.