Data Storage and Data Access at H1

Abstract

Introduction At the electron proton collider HERA at the DESY laboratory in Hamburg, electrons of 27.6 GeV momentum are collided with 820GeV protons at a bunch crossing rate of 10.41 MHz, delivering (design) luminosities of 1:5 \Theta 10 31 cm \Gamma2 s \Gamma1 (peak luminosity) and 50pb \Gamma1 y \Gamma1 (integrated luminosity). The luminosity values reached up to now are 5:0 \Theta 10 30 cm \Gamma2 s \Gamma1 and 5pb \Gamma1 y \Gamma1 , respectively. The large bunch crossing rate poses particularly challenging requirements on the triggering and data acquisition facilities of the experiments. Cross sections for various physics processes at HERA and the resulting data rates are presented in table 1, assuming an