The LHCb experiment is designed to study B and D decays at the LHC, and as such is constructed as a forward spectrometer.  The large particle density in the forward region poses extreme challenges to the subdetectors, in terms of hit occupancies and radiation tolerance. Two methods and their results show no radiation damage of the gaseous straw tube detector after having received a dose of about 0.2 C/cm2 in the hottest area.

The precision measurements at LHCb require accurate alignment of their elements. In Run 2 of the LHC the full potential of the state-of-the-art alignment system RASNIK is being exploited. Relative movements down to 1 um are being monitored.  High accuracy of the RASNIK data allow to track deformations connected with changing magnetic field configurations, operational interventions and environmental conditions. The RASNIK system also provides crucial input to the software alignment by constraining the so-called “weak-modes”, like movements in the longitudinal direction z.