L3 Cosmics electronics

The L3Cosmics project uses the existing L3 muon chambers. The signals from the chambers are picked up from the CPC cards (Cosmic Personality Cards). These PCBs replace the MPC cards (Muon Personality Cards), which are the interface between the discriminator signals and the first and second level muon trigger in L3.
The CPCs contain a copy of the original functionality of the MPCs, plus TDCs and majority logic. The TDCs are read-out via a new channel towards VME. The majority logic is the first step to create a new trigger to start this parallel read-out. The majority signals from the CPCs are combined in the VME crate by a trigger module, the CTT. From the electronics point of view, this set-up is also a pilot project for the read-out system of the Monitored Drift Tubes (MDTs) in Atlas. The NIMROD specification pointed to here describes the ideas we had in 1997 and some related things. The user manual of the currently existing NIMROD is under construction.

You can have a look at:

More about the NIMROD (september 9 1999).
The user manual of the CPC V3 (300 k .PDF, march 19 1999).

bookmarked version

The report on the interference test.(*).
The description of the CTTv2 module for phase 2 (600 k .PDF).
Picture of the CTT: small, 63 k JPG or high definition 530 k JPG
The description of the old CTT module (Trigger and Timing, may 13th 1998)
The discussion place on the phase II trigger requirements.
The Nijmegen L3 Cosmics page.
The L3+Cosmics online page.
The NIKHEF Electronics department page.

(*): Tests have been done whether the functionallity of L3+Cosmics electronics on the CPC card could disturb the normal running of the L3 trigger system.

You can mail

suggestions for this page to: Henk Groenstege.

April 1999