Status of the ILC Main Linac BPM R&D

TL;DR

This paper reviews the current R&D status of high-resolution beam position monitors for the ILC main linac, focusing on two detector concepts and their testing progress.

Contribution

It reports on the development and testing status of two novel BPM detector concepts and associated read-out electronics for the ILC cryomodule.

Findings

Re-entrant resonant coaxial waveguide BPM has passed initial beam tests.

LAPP group is developing radiation-tolerant digital read-out systems.

The 1.5 GHz cavity BPM remains in R&D phase.

Abstract

An introduction and the status of R&D activities for a high-resolution, "cold" beam position monitor (BPM) and the related read-out electronics are discussed. Two different BPM detector concepts, to be attached to the SC quadrupole and located inside the ILC cryomodule, are currently under investigation: A resonant dipole-mode cavity-style BPM pickup, developed at Fermilab, and a re-entrant resonant coaxial waveguide BPM, designed by CEA-Saclay. While the 1.5 GHz dipole-mode cavity BPM is still in the R&D phase, the re-entrant BPM has already passed first beam tests, including its read-out system. Furthermore, the LAPP group is developing radiation tolerant digital read-out systems, which are tested at the CLIC test facility (CTF).