The performance of the CDF luminosity monitor

We describe the initial performance of the detector used for the luminosity measurement in the CDF experiment in Run II at the Tevatron. The detector consists of low-mass gaseous Cherenkov counters with high light yield (similar to 100 photoelectrons) and monitors the process of inelastic pp scattering. It allows for several methods of precise luminosity measurements at peak instantaneous luminosities of 2 x 10(32) cm(-2) s(-1), corresponding to an average of six pp interactions per bunch crossing. (C) 2002 Elsevier Science B.V. All rights reserved.