  In order to fully reconstruct to the reaction e+e- to e+e- gamma-gamma in the
energy region of the phi meson production, new detectors along the DAFNE beam
line have to be installed in order to detect the scattered e+e-. The High
Energy Tagger (HET) detector measures the deviation of leptons from their main
orbit by determining their position and timing so to tag gamma-gamma physics
events and disentangle them from background. The HET detectors are placed at
the exit of the DAFNE dipole magnets, 11 m away from the IP, both on positron
and electron lines. The HET sensitive area is made up of a set of 28 plastic
scintillators. A dedicated DAQ electronics board based on a Xilinx Virtex-5
FPGA have been developed for this detector. It provides a MultiHit TDC with a
time resolution of the order of 500 ps and the possibility to acquire data any
2.5 ns, thus allowing to clearly identify the correct bunch crossing. First
results of the commissioning run are presented.
