This document is a brief introduction to the new LCT simulation. I will update it as time permits.
3 September 1999 The LCT code has changed to reflect the update to the Anode LCT card. This uses the simplified pattern finding found in LCT99-- it simply matches to a possible set of hits and then reports the key wire group. This has excellent resolution and efficiency. The output is in the common block.
15 April 1999 Changed the output common blocks to reflect the current state of the motherboard. Instead of a 28-bit word and common block for each cathode and each anode LCT found, there is now a single common block and a single 44 bit word to describe it all. The 44-bit word is described in the common block description and in the trigger bit document.
Why do we need a new simulation? The new simulation correctly examines how the charges is deposited as a function of time; the old one did not. Also, the new simulation uses the same RAM lookup tables as the hardware. This allows us to change the tables and study the effects. Finally, the new simulation outputs the same 28-bit words (one for each cathode or anode LCT) as the hardware and the same information in an unpacked format. This allows us to examine the actual bit stream the hardware will use.
The LCT finding efficiency is slightly low. My preliminary studies show an efficiency of about 95% for the cathode and 99% for the anode. The design efficiency is close to 97%, and the simulation should certainly be able to get very close to that (if not exceed it!).
There are also problems with CMSIM. The charge deposited on a strip, both singly (the strip with the largest charge on a given layer) and as a group (the largest strip plus the strips +-2 on either side), is too small. The noise on each strip seems to be too small.
I'm working on all these problems and will keep this page updated as much as possible.
Even though this program is not included in CMSIM115, the files used for compiling v115 are needed to have this simulation correctly compile and be included in CMSIM. If you don't have that version installed, contact me and I'll see what we can do to get you running.
Note that, to actually have to code run, you must add this line to your card file:
TRGP 'CMSE' 0 'MUON' 1 'MTRI' 1 'MCFX' 2
The last item is crucial to have CMSIM run the LCT code.
There are three files of interest: lct.tar.gz, a tar'd, gzip'd file containing the simulation; stats.c, a C program that I wrote to examine the logfile and calculate the efficiency of the LCT simulation; and eff.nplot, a file for use with nplot to make quick and dirty plots of said efficiency.
Installation instructions.
Description of the common blocks used.
Contents of lct.tar.gz.
Description of contents of lct.tar.gz.
Preliminary write-up.
I have given a couple of talks about the new simulation...
Benn Tannenbaum (benn@physics.ucla.edu)