Аннотация:The measurement of the energy flow in the forward angular range performed by CMS at LHC
is a means of studying soft particle production and testing hadronic interaction models used in
collider as well as cosmic ray physics. The two important ingredients necessary for the measurement,
forward instrumentation of CMS and the accelerator providing collisions with low pile-up,
performed very well in 2015 at the start up of the operation at 13 TeV.