levan babukhadia

Levan BabukhadiaLevan Babukhadia

D Collaboration Meeting, January 12 - 14, 2000, FermilabD Collaboration Meeting, January 12 - 14, 2000, Fermilab

http://www-d0.fnal.gov/~blevan

Level 1 FPS Algorithm RevisitedLevel 1 FPS Algorithm Revisited

SUNY at Stony BrookSUNY at Stony Brook

DØ Collaboration Meeting, January 12 - 14, 2000, Fermilab Levan Babukhadia

FPS ReadoutFPS Readout

16 FPS 22.5o -sectors4 layers of U- & V-strips

Shower: 144 U- & V-stripsMip: 103 U- & V-stripsSpecial: 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).


L1FPS ArchitectureL1FPS Architecture

L2 PSpp

8N

7N

6N

5N

D4N

DB 3N

DB 2N

DB 1N

F

P

SNORTH

DB 6S

DB 5S

DB 4S

DB 3S

DB 2S

DB 1S

F

P

S SOUTH DB 7S

DB 8S

16

16

N UL3

N V L3

S UL3

S V L3

L1ftp

L3


Truncation in L1FPSTruncation in L1FPS

Possible truncation problems at the Digital Daughterboard and the Collector boardTo address this question study cluster multiplicities in MC

AFE

AFE

FPS -wedge

FPS -wedge

DB

DB

DFE COL

to L1 via BC

Glink to L2

5

5

1

11

Max # of Clusters 18for L2

Max # of Clusters 48


Cluster Occupancies from MCCluster Occupancies from MC

Dijets + 2MB MC with full detector simulation

High SIFT threshold at 5 mips

Excellent agreement withprevious results ( DØ Note 3493 )


Cluster OccupanciesCluster Occupancies

Dijets + 2MB MC with full detector

simulation

Low SIFT threshold at 3 mips

ET: 5 - 10 GeV ET: 10 - 20 GeV

ET: 20 - 40 GeV ET: 40 - 500 GeV


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Cluster OccupanciesCluster Occupancies


simulation

High SIFT threshold at 5 mips

ET: 5 - 10 GeV ET: 10 - 20 GeV

ET: 20 - 40 GeV ET: 40 - 500 GeV


Title:ps/djx6_et4_mip03_vstrips.epsCreator:HIGZ Version 1.23/07Preview:This EPS picture was not savedwith a preview included in it.Comment:This EPS picture will print to aPostScript printer, but not toother types of printers.

Title:ps/djx6_et4_mip03_uclust_vs_vclust.epsCreator:HIGZ Version 1.23/07Preview:This EPS picture was not savedwith a preview included in it.Comment:This EPS picture will print to aPostScript printer, but not toother types of printers.

Dijets MC with 6 MBDijets MC with 6 MBTitle:ps/djx6_et4_mip03_vclusters.epsCreator:HIGZ Version 1.23/07Preview:This EPS picture was not savedwith a preview included in it.Comment:This EPS picture will print to aPostScript printer, but not toother types of printers.

Title:ps/djx6_et4_mip03_vwidths.epsCreator:HIGZ Version 1.23/07Preview:This EPS picture was not savedwith a preview included in it.Comment:This EPS picture will print to aPostScript printer, but not toother types of printers.

Worst case: highestdijet Et 40-500 GeV

andlow SIFT threshold

at 3 mips

Also shows we aresafe at the Collector

board truncation


Title:ps/di_et3_mip03_vstrips.epsCreator:HIGZ Version 1.23/07Preview:This EPS picture was not savedwith a preview included in it.Comment:This EPS picture will print to aPostScript printer, but not toother types of printers.


Strip MultiplicitiesStrip MultiplicitiesTitle:ps/di_et1_mip03_vstrips.epsCreator:HIGZ Version 1.23/07Preview:This EPS picture was not savedwith a preview included in it.Comment:This EPS picture will print to aPostScript printer, but not toother types of printers.



simulation


ET: 5 - 10 GeV ET: 10 - 20 GeV

ET: 20 - 40 GeV ET: 40 - 500 GeV


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Cluster WidthsCluster WidthsTitle:ps/di_et1_mip03_vwidths.epsCreator:HIGZ Version 1.23/07Preview:This EPS picture was not savedwith a preview included in it.Comment:This EPS picture will print to aPostScript printer, but not toother types of printers.



simulation


ET: 5 - 10 GeV ET: 10 - 20 GeV

ET: 20 - 40 GeV ET: 40 - 500 GeV


Proposed Changes in L1FPSProposed Changes in L1FPS

Knowing which - (0.2x0.2) triggertower the FPS cluster is associated withis one way to handle truncation without

introducing physics bias.

To achieve this, U- and V-signals mustbe handled by a single DFE DB

this requires some changes in the cableroutings between AFE and DFE.

Next, the trigger equations allow to dothe - “matching” of identified

U- and V-clusters.

As an example, EQ8 = V8 ( U9 U10 U11 ), when true, will unambiguously identify a cluster as belonging to the trigger tower 2 - 1

V8

U11

U10

U9


SummarySummary

The MC studies indicate we do not have a problemin 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.

levan babukhadia

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