UA9 Beam Loss Monitor

Details
Last Updated: Wednesday, 12 February 2014 09:57

 The UA9 experiment intends to assess the possibility of using bent silicon crystals as primary collimators to direct coherently the beam halo onto the secondary absorber, thus reducing out-scattering, beam losses in critical regions and radiation load. The experiment has been performed in the CERN-SPS in storage mode with a 120 or 270 GeV/c proton beam .In the proximity of the vessel containing the crystals  we mounted scintillators and GEM detectors, to count the rate of nuclear interactions in the crystals and the scatterer.

installazione3

The GEM monitor installed between the two
vessels containing the crystals

 The FPGA acquisition board attached to the
GEM Monitor. The detector is just alongside
the SPS beam pipe

 

 

The active area of 10x10 cm2 of this monitor has been divided into 128 pads, organized in a matrix of 16x8.
In this picture, single particle hits are visible
in a time window of 1 second.

 

Here on the right the history plot (few minutes).
The figure shows the background out of the beampipe
produced by the nuclear interaction of the beam on crystal.
The beam pipe is on top of the figure.
     
 

This is the background flux around the beampipe measured in 1 second during the LHC injection (up to 5 MHz per pad).

 

 

On the left of the picture is visible the injection timeline;
up to 7x108 Hz on the 100cm2 active area.
     
 

In this picture is shown the particle flux measured each second by the gem detector.

The particles are produced by the proton nuclear interaction with the crystal placed in the beam halo.
The measurements has been done during the angular scan:
the dip is due to the channeling of protons inside the crystal
FPGA design and firmware: A.Balla (Laboratori Nazionali di Frascati INFN)