  In this paper important aspects of Lower Hybrid (LH) operation with the ITER
Like Wall (ILW) [1] at JET are reported. Impurity release during LH operation
was investigated and it was found that there is no significant Be increase with
LH power. Concentration of W was analysed in more detail and it was concluded
that LH contributes negligibly to its increase. No cases of W accumulation in
LH-only heating experiments were observed so far. LH wave coupling was studied
and optimised to achieve the level of system performance similar to before ILW
installation. Measurements by Li-beam were used to study systematic
dependencies of the SOL density on the gas injection rate from a dedicated gas
introduction module and the LH power and launcher position. Experimental
results are supported by SOL transport modelling. Observations of arcs in front
of the LH launcher and hotspots on magnetically connected sections of the
vessel are reported. Overall, a relatively troublefree operation of the LH
system up to 2.5MW of coupled Radio Frequency (RF) power in L-mode plasma was
achieved with no indication that the power cannot be increased further.
