FPD Status and Data Quality

Andrew BrandtUTA

Q4D SQ3S

A1A2

P1UP

p p

Z(m)

D1

Detector

Bel

low

s

Roman Pot

233359 3323057

P2OUT

Q2

P1DN P2IND2Q4 Q3 Q2

DØ Workshop June 17, 2003 Beaune, France

All 6 castles with 18 Roman pots comprising the FPD were constructed in Brazil, installed in the Tevatron in fall of 2000, and have been functioning as designed. A2U pot had vacuum leak and was disabled for 6 months and fixed during Jan. 2003 shutdown.

A2 Quadrupole castle installed in the beam line.

Castle Status

• 6 planes per detector in 3 frames and a trigger scintillator

• U and V at 45 degrees to X, 90 degrees to each other

• U and V planes have 20 fibers, X planes have 16 fibers

• Planes in a frame offset by ~2/3 fiber

• Each channel filled with four fibers

• 2 detectors in a spectrometer

0.8 mm

3.2 mm

1 mm

17.39 mm

17.39 mm

UU’

XX’

VV’

Trigger

FPD Detector

• All 18 cartridges have been assembled, 16 are installed in tunnel (10 with full detectors 6 with scintillator only). The 10 instrumented pots (Phase I) are ups, downs, and dipoles.

• Cables and tunnel electronics (low voltage, amp/shapers, etc.) installed and completely operational for Phase I, mostly operational for Phase II 18 pot setup (NSF MRI submitted by NIU+UTA to obtain remaining funds).

• 10 more detectors (includes 2 spares) are complete except for final polishing, which is in progress at Fermilab.

Tunnel and Detector Status

In the October 2001 shutdown four veto counters (designed at UTA, built at Fermilab) each of which cover 5.2 < || < 5.9 were installed between DØ and the first low beta quadrupole (Q4), about 6 m from the interaction point.

The counters, two each on the outgoing proton and anti-proton arms, can be used in diffractive triggering (veto proton remnant).

Veto Counters

Pot Motion SoftwarePot motion is controlled by an FPD shifter in the DØ Control Room via a Python program that uses the DØ online system to send commands to the step motors in the tunnel.

The software is reliable and has been tested extensively. It has many safeguards to protect against accidental insertion of the pots into the beam.

FPD Trigger and Readout

I) AFE1) Added FPD AFE’s, Sequencer, and VRB to CFT database 2) Modified sequencer for FPD timing3) Modified AFE firmware for FPD timing4) Built and extensively tested transition board (TPP) between detector cables and flex cables5) Overcame several installation difficulties 6) Updated FPD AFE packing code7) Created FPD examine8) 2 Boards installed, commissioning in progressII) DFE1) Boards in hand2) Trigger equation firmware being tested in combined test standIII) LM electronics to read out trigger scintillator and for FPD triggerIV) TM 1) Components installed, cables laid, commissioning ready to begin

FPD IntegrationSubstantial, if not speedy, progress (stand-alone DAQ in parallel)

In-time hits in AU-PD detectors, no early time hits, or LM or veto counter hits

A1U A2U

P2DP1D

P

Pbar Halo Early Hits

LMVC

bpbf pxp

bpp

Elastic Data

Approximately 3 million elastic triggers taken with stand-alone DAQ

About 1% (30,000) pass multiplicity cuts–Multiplicity cuts used for ease of reconstruction and to remove halo spray background

• After alignment correction, peaks at 0 (as expected for elastics)– MC resolution is 0.013 (including z smearing and dead channels), data is 0.015, 1.15 times larger

• The t distribution has a minimum of 0.8 GeV2; tmin is determined by how close the pots are from the beam, shape is in rough agreement with expected angular acceptance from MC.

|t| (GeV2)

DØ Preliminary

-reco

Elastic Data Distributions

• Can see bunch structure of both proton and antiproton beam

• Can reject proton halo at dipoles using TDC timing

• CDF does not have this capability (neither do we until LM Run II electronics operational!)

D1 TDC

D2

TDC

pbar

p

DØ Preliminary

Dipole Data Timing

• Continue with FPD expert shifters inserting pots and Captains removing pots and setting system to standby

• Pots inserted almost every store• Commissioning integrated FPD • Soon will add new AND/OR terms and FPD triggers• Will combine shifts with CFT when routine data taking begins• Working towards automated pot insertion (CAP)

FPD Operations

• Monte Carlo Tools– MC for Diffractive Physics (POMPYT, POMWIG, SCIPYT): released– FPD is fully integrated in DØgStar:– FPD geometry + beamline in DØgStar + DØSim FPDDigiChunk

• L3 Tools– Tracking: released– Unpacking: released– Single Interaction Tool: released– Not tested on raw data

• Offline Tools– Unpacking: released and tested on raw data– Implementing multihits environment in the tracking algorithm– FPD_Reco: released. Needs raw data testing– Geometry: pre-release version

Software Status

Vladimir Sirotenko, May 2003

Rate Watcheron d0ol49

ACNET

acnetServer

EPICS

COORNVServer

Brun/ErunFiles

RunGrabberRUNS

Database

FPD data

Goal: access information about FPD experimental setup and accelerator conditions which is available through EPICS during reconstruction & analysis of data

In progress

FPD Runs Database

• FPD_Reco Integration: D0Reco• Trigger Simulator: Raw Data• L3 Geometry: Offline• DST & TMB Info: D0reco (p13)• FPD_Analyze: Offline (DST+TMB)• Alignment Tool (offline): Elastic stream• Calibration Tool (offline): LMB + Data

Missing Software

Partial list of steps needed to get to physicsquality data:

• Commission AFE’s• Refine FPD_Examine• Include trigger scintillator information/ basic AND/OR terms• Alignment of FPD• Finalize FPD database• Activate FPD_Reco• Halo understanding, reduction, and rejection• FPD info in DST’s and Thumbnails

Getting to the Physics

Operating position determined by halo: either 10% affect on DØ halo, or rates in our pots >180 khz.

Simulations (Mokhov, Drozhdin) indicated 8-9 feasible.Reality 50-100 times worse, due to neglected single pass halo generation term 10 or worse

Effects:1) acceptance for quad spectrometers drops by x3/beam !)2) radiation damage (<10% gain loss in 5 years to > 50% depending on extrapolation)3) variable halo rates makes automatic pot insertion more difficult.

Studies of home rates vs p-halo (D0PHTL) and A-halo (D0AHTL) show that 35 kHz and 2.5 kHz respectively give tolerable rates (routinely exceeded)

Working with BD on detailed plan for halo study and rejection

Halo

• Early FPD stand-alone analysis shows that detectors work• FPD is now integrated into DØ readout, but detector

commissioning and trigger still in progress

Goals for 2003: Data taking with integrated Phase I Add FPD triggers to global list Complete funding and implementation of Phase II Preliminary results on several physics topics

New (wo)manpower would not be turned away!

Summary and Plans