Sep 25 – 29, 2006
Valencia, Spain
Europe/Zurich timezone

A compact plug-in module for LHC-like trigger emulation

Sep 27, 2006, 4:20 PM
1h 40m
Valencia, Spain

Valencia, Spain

IFIC – Instituto de Fisica Corpuscular Edificio Institutos de Investgación Apartado de Correos 22085 E-46071 València SPAIN


Georgios Sidiropoulos (University of Ioannina)


A programmable random trigger emulation system has been built for use in high energy physics, nuclear physics or radiology experiments. The emulator is based on the generation of trigger time intervals using a true random bit generator. The system is able to work either as a stand alone trigger emulator or as a plug-in module for a trigger/readout system.


The requirement of a device emulating the arrival of particles
on a particle
detector is apparent in the construction phase of the
corresponding readout
electronics and DAQ system.
The emulator produces randomly generated trigger pulses
with time intervals
following an exponential distribution with programmable
mean between 1 KHz and 1
MHz (trigger rate). The source of randomness is the
avalanche effect on a
transistor emitter-base diode biased by a digitally controlled
voltage source.
Therefore, by changing the diode biasing the desirable
trigger rate is obtained.
The output of the random generator is treated by a digital
processing circuitry
implemented in an FPGA.
The digital processing includes:
• emulation of experiment specific features e.g. the
arrangement of the LHC
bunches during the LHC operation cycle,
• trigger specific rules e.g. maximum consecutive
triggers with minimum
arrival times.
Burst of 1000 random triggers are recorded and can be
played back. In addition to
the random triggers, the system also supports fully
programmable trigger generation
in order to test other distributions. When working as a
stand alone trigger
generator, the system is controlled by a standard pc via the
USB interface.
The system has been extensively evaluated. The
output of the true random
generator has been verified using the NIST battery of tests
for random number
generators. Finally, the system has been calibrated in
respect to the trigger rate.

Primary author

Georgios Sidiropoulos (University of Ioannina)


Prof. Nikolaos Manthos (University of Ioannina) Mr Paschalis Vichoudis (CERN)

Presentation materials