  The upgrade of the LHC to the High-Luminosity LHC (HL-LHC) is expected to
increase the current instantaneous luminosity by a factor of 5 to 7, providing
the opportunity to study rare processes and measure precisely the standard
model parameters. To cope with the increase in pile-up (up to 200), particle
density and radiation, CMS will build new silicon tracking devices with higher
granularity (to reduce occupancy) and improved radiation hardness. During the
R&D period tests performed under beam are a powerful way to develop and examine
the behavior of silicon sensors in realistic conditions. The telescopes used up
to now have a slow readout (less than 10 kHz) for the needs of the CMS
experiment, since the new outer-tracker modules have an effective
return-to-zero time of 25 ns (corresponding to a 40 MHz frequency) and a
trigger rate of 750 kHz. In order to test the CMS Tracker modules under the LHC
nominal rate, a pixel telescope named CHROMIE (CMS High Rate telescOpe MachInE)
is designed, built and commissioned at CERN for beam tests with prototype
modules for the CMS Phase-2 Tracker upgrade. In this article the design of
CHROMIE, the calibration of its modules, and its timing and synchronization
aspects are presented, along with the first beam test results. In addition, the
tracking algorithm developed for CHROMIE and a preliminary Geant4 simulation
study of the telescope under beam are discussed.
