# Presentation: 037386

## SciFi  Electronics

**SVX** : pulse height digitization and readout for offline reconstruction
**L1 Trigger** : fast discrimination and online track pattern matching

- Boeing Meeting, 30 - November -2000                                                       Stefan Grünendahl

## Electronics Overview

- On cassette: discrimator and ADC chips
- Readout path : SVX - Sequencer - VME Readout Buffer - VBD - L3 event processors - host system: data storage & monitoring
- Trigger path: discriminator - Mixer crate - clustering/track equation matching - multi-sector concentrator - L1 framework & L2 preprocessors

- Boeing Meeting

- November 30, 2000

## Frontend Signal Flow

- Analog FE Board:
-  VLPC
-  (Charge Divider) (for Preshower  Detectors)
** ****SIFT Discriminator** (with SVX) in   Multichip Module
-  Hit **Latch**
- Mixer Subsystem:
- 16 lvds inputs/board
- 4 boards/supersector (1/5 of SciFi)
- Digital FE Board:
** ****Tracking** FPGA
** ****Sorting** of Track Lists
-  Shipping to Muon L1 System
** ****Preshower Matching**
** ****Sorting** of (matched) Track +  Preshower Lists
** ****Shipping** to Concentrator Subsystem

- Boeing Meeting

- November 30, 2000

## SciFi  VLPC Cassette

- 1024 VLPC channels
- two FE boards = two 4.5° trigger sectors
- CFT Trigger Boards:
- 480 CFT channels, 32 CPS channels/board
- 1 SIFT + SVX channel per CFT channel housed in 7 Multi Chip Modules (MCM’s)
- 2 SIFT + SVX channels per CPS channel

- Boeing Meeting

- November 30, 2000

## AFE

- Boeing Meeting

- November 30, 2000

## FE components: SIFT + SVX

**FE components: SIFT + SVX**

- SIFT : ASIC by ADEPT IC Design in 0.8 m technology
- 1 SIFT - SVX channel per CFT Fiber
- 2 SIFT - SVX channels per preshower channel
- Housed in 1 MCM (2 trigger thresholds - 1 high and 1 low)

- timing

- Boeing Meeting

- November 30, 2000

## Pulse Height Readout

- SVX analog buffer: pipelines every channel, every bunch crossing for 3 s, until L1 decision made
- Digitization and Transfer through Sequencer to VRB (VME Readout Buffer) upon L1 Accept (10 kHz)
- Transfer through VBD (VME Branch Driver) to L3 event processor farm upon L2 accept (1 kHz)
- data logged to disk/tape upon L3 accept (10-20 Hz)

- Boeing Meeting

- November 30, 2000

## Sequencer

- SVX download & control, data protocol translation from 8-bit parallel to G-link

- Boeing Meeting

- November 30, 2000

## VRB

- Single Width 9U x 400mm VME64x/VIPA Module.
-      Slave Interface Supports D32 Block Transfer Rate Up to 40 MBytes/sec
-          Conforms to VME 64 Draft Specifications, Rev. 11.1.
-      External Buffer Management and Status Monitoring via P5/6 connector.
-      Re-Programmable Logic Supports Multiple (or Moving Target) Applications
-      Supports True Simultaneous Buffer Memory Reads & Writes
-      10 Channel (53 MBytes/sec 8-bit) TTL Port  on Rear Connector
-          Optical 4-Ch (1.5 Gb/s )G-Link Transition Module or
-          Optical 10-Channel 175Mb/s TAXI Transition Module
-      Programmable Number of Buffers & Buffer Size per Channel
-          64-Buffers x 1-Kbytes  . . . 1-Buffer x 64-Kbytes

- Boeing Meeting

- November 30, 2000

## Trigger Schematic

- Boeing Meeting

- November 30, 2000

## Trigger Architecture

**L1 Trigger**

**L1**

**Global L2 Stage**

**L2 Preprocessors**

**Buffers**

**Silicon**

**SciFi**

**PS**

**Muon**

**Calo**

**p-bar**

**p**

**L3 **
**Processors**

**Trigger**
**Framework**

**10 kHz**

**1kHz**

**10-20Hz**

**tape**

**250kb/evt**

**L0**

- Boeing Meeting

- November 30, 2000

## L1/L2 Trigger Configuration

**L1/L2 Trigger Configuration**

- Boeing Meeting

- November 30, 2000

## Trigger Example

_**Central Electrons:**_

- L1 Terms:
-     1 Central EM tower > 7 GeV
-                   plus
-     1 CFT track > 6 GeV/c
-          with Matching CPS
- L1 Rate 220 Hz

- L3 Terms:
-     ET > 20 GeV
-     Shape Cuts
- L3  = 0.01 b,  2 Hz

- L2 Terms:
-     ET > 7 GeV
-     Isolation, Shape Cuts
-     Match Cluster / Track
- L2  Rate 48 Hz

- Boeing Meeting

- November 30, 2000

## Central Tracking Trigger

- Feed all axial fibers plus preshower into gate arrays
- Trigger if a fiber combination is consistent with PT > (1.5,3,6,8) GeV
- Tag categories (incl. CPS info): track, isolated track, electron, ...

- Trigger response for Z ee with 4 min.bias

- Boeing Meeting

- November 30, 2000

## Overview SciFi  & Preshower L1

- Design principles:
- shared motherboard / daughtercards / transition modules
- point-to-point LVDS links
- scheme:
- Analog Front-end
- Mixer Crate
- Digital Front-end w/ controller
- Concentrator (Octant, Quadrant and Singlet Boards)
- (Muon) Trigger Manager
- links:
- internal all lvds
- serial copper (AMCC) to 80 Muon sectors
- serial fiber (G-link) to L2, L3

- Boeing Meeting

- November 30, 2000

## Systems Description

- _CFT/CPS Trigger_
- CFT Axial fibers and CPS Axial strips.
- Forms the L1 Fiber Tracker Trigger
- supports the L2
- Central Fiber Tracker preprocessor, CFTpp,
-  the Preshower preprocessor, PSpp,
- the proposed Silicon Tracking Trigger preprocessor, STTpp.
-  _CFT Stereo_
- CFT Stereo fibers.
- Uses SIFT for longer charge integration time.
**This is a FE system only and does not support any trigger.**
- However, discriminator hits could be available at L2 and/or L3.

- _PS Trigger_
- Forward Preshower strips and Central Preshower Stereo strips.
- The FPS strips are used to form the L1 Forward Preshower Trigger.
- The FPS and CPS stereo strips are used for the L2 Preshower Trigger preprocessor, PSpp.
- _FPD Trigger_
- The detector inputs for this system are the Forward Proton Detector.
- These inputs will be used to form the L1 Forward Proton Detector Trigger.
-  supports the L2 Forward Proton Detector preprocessor, FPDpp.

- Boeing Meeting

- November 30, 2000

## Hardware Components

- _Analog FE System_
- AFE Analog FE board
- 2 types:  8 MCM (CFT/CPS axial) and 12 MCM (CPS/FPS)
- Both boards Unhanded
- _Mixer System_
- CTT_MX Mixer board & crate
- _Digital FE System_
- DFE Digital FE board
- 3 flavors: Axial, Stereo (CPS), FPS
- 	Digital-Crate Controller board : stores FPGA firmware configurations

- _L1/L2 Concentrator System_
- OCTANT boards : counts & lists for L1 & L2
- QUADRANT boards : track/preshower lists for L2
- CTTT/CPTT/FPTT	Singlet boards
- _Trigger Manager System_ ( from the L1 Muon system)
- Trigger Manager boards - borrowed from Muon system
- plus several boards from muon in two crates

- Boeing Meeting

- November 30, 2000

## The Digital Board

- Digital Board daughtercards are application-dependent:
- Axial trigger (DFE)
- Collector ('octet')
- Concentrator ('singlet')
- Roman pot trigger

- DFE Daughtercard

- Boeing Meeting

- November 30, 2000

## DFE Crate

**DFE Crate**

- Boeing Meeting

- November 30, 2000

## Links and Signal Routing

- Boeing Meeting

- November 30, 2000

## SciFi  /PS Digital Frontend Board

- Boeing Meeting

- November 30, 2000

## CFT/CPS Geometry

- Geometry for the CFT L1 and L2:
- Octants to L1CFT (matches calorimeter geometry)
- Sextants to L2CFTpp & L2STTpp (matches silicon geometry)

- Boeing Meeting

- November 30, 2000

## Concentrator Functions

**CTOC/CTQD/CTTT****	****(Octant, Quadrant and Singlet boards)**
- Receive L1 sums from several DFEA boards:
- track sums for CFT
- cluster sums for FPS.
- Form L1 sums into sums by Octant/Quadrant.
- Transmit the octant sums to the CTT_Trigger Manager.
- Transmit copies of the input and output data to the L3 readout.
- Receive the L2 track/cluster lists from several DFEA boards.
- Concatenate the lists from several DFEA boards.
- Transmit the resulting track/cluster lists to various L2pp matching the phi segmentation for that L2pp.

- Boeing Meeting

- November 30, 2000

## Summary

- SIFT a major disappointment
- Everything else works well

- Boeing Meeting

- November 30, 2000

## Backup slides

## Physics Goals

- Precision Tests of the Standard Model
-     Continuation of present DØ physics
-      program, with some shift  in emphasis
- precision measurements
-        (top mass, W mass, ...)
- Constrain the Higgs Boson Mass
- improvements to B physics capabilities
-     (Bs mixing, approach to CP violation, ...)
- QCD with W,Z, 
- Extend the Discovery Reach
-      Significant improvement to physics reach
- few fb-1 data samples allow significant increases in the reach for SUSY, leptoquarks, W’,Z’,anomalous couplings....
-  Extended luminosity  (5 - 25 fb -1): intermediate mass Higgs

- Boeing Meeting

- November 30, 2000

## The Detector

- The DØ upgrade builds upon the strengths of the existing detector
-  (excellent calorimetry, muon coverage) and augments it with a
- high resolution Silicon/Scintillating Fiber tracker.

- calorimeter: replacement of preamps/shapers
- muon system:
- replacement of muon chamber readout electronics
- Iarocci drift tubes replace forward muon chambers
- central and forward scintillator pixel layers enhance trigger capability.
- DAQ & trigger: add buffering, add processing power
- central tracker:
- 2 T supraconducting coil inside r=70 cm calorimeter bore
- lead/scintillator preshower detector with fiber/VLPC readout
- 16 layer SciFi/VLPC tracker (80k channels)
- 4 barrel / 16 disk Silicon tracker (1M channels)
- forward tracker/preshower: scintillator cells with fiber/VLPC readout

- Boeing Meeting

- November 30, 2000

## Tevatron Impact

- Impact on DØ
- Integrated *L *rad damage in tracking chambers replace
- Shorter bunch crossing interval avoidpileup   electronics pipeline
- Systems either Upgraded **Cal, Muon,Trig/DAQ **
**	****   ****	**or:                 Replaced **Tracking System**
- Solutions involve new Detector Technologies
- Silicon strip detectors, SciFi, trigger processors
-    The DØ Upgrade is designed to exploit unique opportunities offered by the Tevatron during Run II **and beyond**

- Boeing Meeting

- November 30, 2000

## DØ Tracking

**DØ Tracking**

**calorimeter cryostat**

**1.1**

**1.7**

- 1.3 m

- 50 cm

- Solenoid
- 2T superconducting
- Fiber Tracker
- Eight layers sci-fi ribbon doublets               (x-u or x-v)
- 77,000  830 m fibers w/ VLPC readout
- Silicon Tracker
- Four layer barrels (double/single sided)
- Interspersed double sided disks
**800,000 channels**
- Preshowers
-    Central
** **Scintillator strips
-  6,000 channels
- Forward
-  Scintillator strips
-  16,000 channels

- Boeing Meeting

- November 30, 2000

## Fiber Tracker

**Fiber Tracker**

**Barrels**
**8 carbon fiber barrels**
**20<r<50cm**
**full coverage to********= 1.7**
**Scint Fibers**
******m ****Ø****, ****multiclad**
**2.6m active length**
**10m clear waveguide to photodetector**
**rad hard  (100 krad)                (10yr @ 20cm @10****32****)**
**Fiber Ribbons**
**8 axial doublets**
**8 stereo doublets        (2****o**** pitch)**
**Readout**
**77,000 channels**
**VLPC readout**
**run at low temp (9 K)**
**fast pickoff for trigger**
**SVXII readout**

**side view**

**end view**

- Boeing Meeting

- November 30, 2000

## Fiber Tracker

**Visible Light Photon Counter (VLPC)**
**Avalanche  Photo Diode**
- well matched to light from fiber ( = 525 nm)
- quantum efficiency 
- fast response, high rate capability
- Si:As (band gap = 0.05 eV)
- high gain (, low gain dispersion
- operate at
-   8 K < T < 10 K,  6 V < Vbias< 7.5 V

- Boeing Meeting

- November 30, 2000

## Tracker Performance

- Tracking
-   momentum resolution significantly enhanced
- secondary vertexing capability with silicon  tag b-quark decays
- sign determination for electrons
**triggering** using central tracking
- Preshowers
- enhanced e and photon ID (central & forward)
- forward e-triggering: additional x3-5 rejection

- Boeing Meeting

- November 30, 2000