Diamond-like carbon coatings for cryogenic operation of particle detectors

Characterization of diamond-like carbon (DLC) coatings at cryogenic temperatures (down to 77 K) is presented, covering the electrical resistivity range practical interest gaseous and liquid particle instrumentation: 10^-1-10^5 Mohm/sq. The good behaviour observed in terms linearity, surface uniformity stability with time transported charge add other well-known characteristics like low chemical reactivity tolerance radiation. temperature dependence properties consistent a conductivity mechanism based on 2-dimensional variable-range electron hopping, as expected for thin films made from amorphous carbon. First results resistive-protected WELL detector ('RWELL') built DLC operated close liquid-vapor coexistence point argon (87.5 K 1 bar) are presented.