Levan Babukhadia

1. This presentation will probably involve audience discussion, which will create action items. Use PowerPoint to keep track of these action items during your presentation • In Slide Show, click on the right mouse button • Select “Meeting Minder” • Select the “Action Items” tab • Type in action items as they come up • Click OK to dismiss this box This will automatically create an Action Item slide at the end of your presentation with your points entered. D Collaboration Meeting, January 12 - 14, 2000, Fermilab Level 1 FPS Algorithm Revisited Levan Babukhadia SUNY at Stony Brook http://www-d0.fnal.gov/~blevan

2. FPS Readout 16 FPS 22.5o-sectors 4 layers of U- & V-strips Shower: 144 U- & V-strips Mip: 103 U- & V-strips Special: 72 U- & V-strips Total max ~500 analog signals per FPS -sector Two FPS -sectors  Two Analog Front End (AFE) boards on a single VLPC cassette. High and Low SIFT thresholds set at AFE output (~doubles the # of analog signals).

3. DB 1N F P S DB 2N L2 PSpp DB 3N N U L3 DB 1S D4N NORTH N V L3 DB 2S F P S 5N DB 3S S U 6N L3 SOUTH DB 4S 7N L1ftp S V L3 DB 5S 8N 16 DB 6S L3 DB 7S 16 DB 8S L1FPS Architecture

4. Max # of Clusters 18 for L2 DFE COL 1 5 FPS -wedge AFE DB 1 to L1 via BC 5 1 FPS -wedge AFE DB Glink to L2 Max # of Clusters 48 Truncation in L1FPS Possible truncation problems at the Digital Daughterboard and the Collector board To address this question study cluster multiplicities in MC

5. Cluster Occupancies from MC Dijets + 2MB MC with full detector simulation High SIFT threshold at 5 mips Excellent agreement with previous results ( DØ Note 3493 )

6. Cluster Occupancies ET: 5 - 10 GeV ET: 10 - 20 GeV Dijets + 2MB MC with full detector simulation Low SIFT threshold at 3 mips ET: 20 - 40 GeV ET: 40 - 500 GeV

7. Cluster Occupancies ET: 5 - 10 GeV ET: 10 - 20 GeV Dijets + 2MB MC with full detector simulation High SIFT threshold at 5 mips ET: 20 - 40 GeV ET: 40 - 500 GeV

8. Dijets MC with 6 MB Worst case: highest dijet Et 40-500 GeV and low SIFT threshold at 3 mips Also shows we are safe at the Collector board truncation

9. Strip Multiplicities ET: 5 - 10 GeV ET: 10 - 20 GeV Dijets + 2MB MC with full detector simulation Low SIFT threshold at 3 mips ET: 20 - 40 GeV ET: 40 - 500 GeV

10. Cluster Widths ET: 5 - 10 GeV ET: 10 - 20 GeV Dijets + 2MB MC with full detector simulation Low SIFT threshold at 3 mips ET: 20 - 40 GeV ET: 40 - 500 GeV

11. Proposed Changes in L1FPS Knowing which - (0.2x0.2) trigger tower the FPS cluster is associated with is one way to handle truncation without introducing physics bias. To achieve this, U- and V-signals must be handled by a single DFE DB  this requires some changes in the cable routings between AFE and DFE. Next, the trigger equations allow to do the - “matching” of identified U- and V-clusters. V8 U9 U10 U11 As an example, EQ8 = V8  ( U9  U10  U11 ), when true, will unambiguously identify a cluster as belonging to the trigger tower 2 - 1

12. Summary The MC studies indicate we do not have a problem in L1FPS DFE truncation at 18 H&L clusters. Still, the proposed modifications in: (a) cable routings between AFE and DFE to allow U-V “matching” in DFE DB & (b) L1FPS DFE algorithm to allow the determination of the - trigger tower assoiciation of the L1FPS cluster are to be implemented. As a result, the truncation is not expected to be a problem even in higher background environment during actual running.