Author: alexchen; Andreas Jansson
Date: 2004-04-28

AN IONIZATION PROFILE MONITOR
FOR THE TEVATRON

A. Jansson, M. Bowden, K. Bowie, A. Bross, R. Dysert, T. Fitzpatrick, R. Kwarciany, C. Lundberg, H. Nguyen, C. Rivetta, D. Slimmer, L. Valerio, J. Zagel, Fermilab, Batavia, IL, USA

f

ion

Proton beam

Pbar beam

Micro chan nel plate

e-

E=100kV/m

B=0.2T

Primarily to study emittance blowup during injection and ramping, an ionization profile monitor has been developed for the Tevatron. It is based on a prototype installed in the Main Injector, although with extensive modifications. In particular, the electromagnetic shielding has been improved, the signal path has been cleaned up, and provisions have been made for an internal electron source. Due to the good Tevatron vacuum, a local pressure bump is introduced to increase the primary signal, which is then amplified by a microchannel plate and detected on anode strips. For the DAQ, a custom ASIC developed for the CMS experiment is used. It is a combined charge integrator and digitizer, with a sensitivity of a few fC, and a time-resolution that allows single bunch measurement. Digitization is done in the tunnel to reduce noise. Preparations for detector installation were made during the long 2004 shutdown, with the installation of magnets, vacuum chambers, vacuum pumps and cabling. The actual detector will be installated during the fall 2005 shutdown. This paper describes the design of the detector and associated electronics, and presents various bench test results.

Abstract

Background

RPAT032

Detector

Timing

Electronics

QIE Chip

Signal Simulations

Tunnel Installation

Controlled vacuum leak

Software

Bench Measurements

Electron Tracking

Radiation Measurements

MCP Measurements

Histogram of the pedestal noise (1.8fC rms)

Pulse injected with laser-PMT system