Ricerc@Sapienza

The Extreme Light Infrastructure – Nuclear Physics
Gamma Beam Source (ELI-NP GBS) facility will provide
an high intensity laser and a very intense gamma beam for
various experiments. The gamma beam is generated
through incoherent Compton back-scattering of a laser
light off a high brightness electron beam provided by a
720MeV warm LINAC. The electrons are organized in
compact trains with up to 32 bunches, each separated by
16ns. To optimize the laser-electron interaction and
therefore the generation of the gamma rays, one big
challenge is to precisely monitor the trajectory of each
electron bunch.
To match this requirement, at the interaction point two
S-band cavity beam position monitors will be used, and
the related readout system should perform bunch-bybunch
position measurements with sub-?m resolution.
Using 500MS/s ADC converters and dedicated data
processing, the readout system proposes an alternative
measurement concept. In this paper the architecture of the
system, the implemented signal processing and the results
of the first laboratory tests will be presented.