TOTEM Setting Out towards New Discovery Horizons
With the first LHC long shutdown approaching its end, TOTEM is looking back on a busy year marked on one hand by Run-1 data analysis culminating in 3 publications and more in progress, and on the other hand by a major consolidation and upgrade of its Roman Pot system.
In particular, two new Roman Pots with a completely new design, minimising the beam-coupling impedance, have been developed, built and installed.
Roman Pot stations in the LHC tunnel
Furthermore four existing Roman Pots were equipped with specific Radio Frequency shields, integrated in new bellows. All other pots were equipped with new ferrites to comply with the ultra high vacuum requirements of LHC.
The new configuration, concentrating 13 Roman Pots between 200 and 220 m on each side of IP5, constitutes the largest, most comprehensive and powerful leading proton spectrometer ever in existence in a collider, and will soon be put into operation for pursuing TOTEM's substantially upgraded physics programme.
In addition to the measurement of the elastic and total cross-sections at the LHC's ultimate energy, the door has been opened to exploring new physics, in particular via particle production in central diffractive processes, to be studied both as a standalone experiment and in the framework of CT-PPS, the common project with CMS. While first exciting discoveries, e.g. possible low-mass glueball states, may already be within reach in low-luminosity beam conditions early in Run 2, rarer hard-diffractive processes will require operation at high luminosities with high event pileup probabilities, for which the foundations have already been laid with the start-up of development work for time-of-flight detectors to be installed in several Roman Pots.
First testbeam measurements with diamond detector prototypes and a custom-built high-precision clock distribution system have shown a time resolution of 82 ps, fulfilling the requirements from the physics programme for runs at high-beta beam optics.
All technical upgrades and their impact on the physics potential have been documented in two Technical Design Reports, both favourably received by the LHCC. Anticipating an intense commissioning phase, TOTEM is enthusiastically looking forward to the first beams in 2015.