How to construct a second-order achromat with a 90 degree phase advance

Kobilarcik, T.

Fermi National Accelerator Laboratory

关键词: 43 Particle Accelerators;    Geometrical Aberrations;    Beam Optics;    Accelerators;    Transformations;   

DOI  :  10.2172/757593
RP-ID  :  FERMILAB-TM-2119
RP-ID  :  AC02-76CH03000
RP-ID  :  757593

美国|英语

来源: UNT Digital Library

【 摘 要 】

The author shows how to construct a second order achromatic (T{sub ij6} = 0, i, j {element_of} {l_brace}1,2{r_brace}) beamline with a total phase advance of 450{degree} (360{degree} + 90{degree}). The goal is to construct a 90{degree} cell which is achromatic to second order. One possible way to do this is to construct a 360{degree} sector followed by a 90{degree} cell; put dipoles and sextupoles in the 360{degree} sector; and throw the aberrations into the 90{degree} cell such that the final transformation is achromatic. The author expresses the aberrations in the 360{degree} sector in terms of the 90{degree} cell and determine whether any combination of sextupoles gives the correct cancellation.