LUCX – laser undulator compact x-ray project at KEK is a multipurpose linear electron accelerator. A new, 3.6 cell RF gun with a high mode separation and a high Q value is installed to produce a multi-bunch high quality electron beam with up to 1000 bunches, a 0.5-nC bunch charge, and 10-MeV beam energy which is accelerated to 30 MeV by the normal conductivity 3-m S-band accelerating structure [M. Fukuda et al., NIMA, 637 (2011) S67–S71]. Recently the upgrade plan involving replacement of the 3 m structure by 1 m 12-cell mode-separated booster and introducing new femtosecond Ti-Sapphire laser system for RF Gun has been released [Quantum Beam Technology Program NEWS No. 8 (QBT News No. 8) published by KEK QBT Group].