The Linear IFMIF Prototype Accelerator, LIPAc, is being
commissioned aiming at validating the RFQ up to 5 MeV
beam acceleration. Eventually, the nominal beam of
5 MeV–125 mA in 1 ms length and
1 Hz rate pulsed mode was achieved in 2019. The beam
operation has been resumed since July 2023 after a long maintenance
including recovery from unexpected problems in the RFQ-RF
system. This new phase aims at the commissioning of the full
configuration except SRF LINAC, which is replaced by a temporary
beam transport line. Focusing on the RFQ behavior, it will be
interesting to operate it at higher duty, especially for longer
pulses. Furthermore, a beam simulation study suggested that the beam
extracted from the RFQ includes considerable momentum halo when the
vane voltage reduces by more than 5 %, with a slight decrease of
the mean energy. It can be a potential source of a quench like the
mismatched beam in the cryomodule. This could be studied by
measuring the energy from the Time-of-Flight among multiple BPMs
while monitoring beam loss around the dipole, where momentum halo
should be lost. During the beam commissioning phase, we studied them
by scanning the RFQ voltage.