Error and jitter effect studies on the SLED for BEPCII-linac

TL;DR

This paper investigates how errors and jitters affect the performance of the SLED RF pulse compressor used in the BEPCII linac, including re-deriving formulas and analyzing their impacts on output wave quality.

Contribution

The paper provides a re-derivation of the generalized formulas for SLED and analyzes the effects of errors and jitters on its performance.

Findings

Error effects include frequency drift from cooling water temperature changes.

Jitter effects involve PSK switching phase and timing jitters.

Performance deterioration impacts amplitude and phase stability.

Abstract

RF pulse compressor is a device to convert a long RF pulse to a short one with much higher peak RF magnitude. SLED can be regarded as the earliest RF pulse compressor used in large scale linear accelerators. It is widely studied around the world and applied in the BEPC and BEPCII linac for many years. During the routine operation, the error and jitter effects will deteriorate the SLED performance either on the output electromagnetic wave amplitude or phase. The error effects mainly include the frequency drift induced by cooling water temperature variation and the frequency/Q0/{\beta} unbalances between the two energy storage cavities caused by mechanical fabrication or microwave tuning. The jitter effects refer to the PSK switching phase and time jitters. In this paper, we re-derived the generalized formulae for the conventional SLED used in the BEPCII linac. At last, the error and jitter effects on the SLED performance are investigated.