How many IVUs can we install without sacrificing 16-mA operation?

Chae, Y.-C. ; (APS), Accelerator Systems Division

Argonne National Laboratory

关键词: Wiggler Magnets;    Dimensions;    43 Particle Accelerators;    Boundary Conditions;    Electrons;   

DOI  :  10.2172/982652
RP-ID  :  ANL/APS/LS-318
RP-ID  :  DE-AC02-06CH11357
RP-ID  :  982652

美国|其它

来源: UNT Digital Library

【 摘 要 】

In this note, the authors examine the following hypothetical scenario: replacing existing 8-mm gap chambers with an in-vacuum undulator (IVU) one by one until they hit the boundary condition of 16-mA single-bunch operation. This is a continuation of a previous technical note on the topics of IVUs. The authors evaluated the impedance of IVU for various gaps. The result showed that the present 8-mm gap chamber can be replaced by the 8.754-mm IVU while maintaining the same 16-mA operational current. The estimates in this note make certain simplifying assumptions bearing on the effectiveness of nonlinear tapers. Subsequent evaluation of the effect of such tapers for APS parameters has cst considerable doubt on their usefulness. This results from the fact that APS has a fairly short electron bunch compared to the vacuum chamber dimensions. Investigation of other methods to decrease the impedance is on-going.