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D FPD Introduction Andrew Brandt UTA

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Title: D FPD Introduction Andrew Brandt UTA


1
DØ FPD Introduction Andrew BrandtUTA
February 20, 2003 FPD mini-workshop Fermilab
2
EVENT TOPOLOGIES
3
Diffractive Variables
pBeam
pF
P
Pomeron Exchange
Non-diffractive
For TeV
For
GeV
GeV
(Note
)
GeV
4
Diffraction Thesis Topics Soft Diffraction and
Elastic Scattering Inclusive Single
Diffraction Elastic scattering (t
dependence) Jorge Molina Total Cross Section
Centauro Search
Inclusive double pomeron
Search for glueballs/exotics Hard
Diffraction Diffractive jet Michael Strang
Diffractive b,c
Diffractive W/Z
Diffractive photon
Diffractive top Diffractive Higgs
Other hard diffractive topics
Double Pomeron jets Tamsin
Edwards Other Hard Double Pomeron topics
Rapidity Gaps Central gapsjets
Topics in RED were studied
Gap tags vs. proton tags
with gaps only in Run I Double pomeron with
gaps
lt100 events in Run I, gt1000 tagged events in Run
II
5
Data Taking
  • No special conditions required
  • Read out Roman Pot detectors for all events
  • (cant miss )
  • A few dedicated global triggers for diffractive
  • jets, double pomeron, and elastic events
  • Use fiber tracker trigger board -- select
  • x , t ranges at L1, readout DØ standard
  • Reject fakes from multiple interactions
  • (Ex. SD dijet) using L0 timing, silicon
  • tracker, longitudinal momentum conservation,
  • and scintillation timing
  • Obtain large samples (for 1 fb-1)
  • 1K diffractive W bosons
  • 3K hard double pomeron
  • 500K diffractive dijets

with minimal impact on standard DØ
physics program
6
Acceptance
x
Quadrupole ( p or )
450 400 350 280 200
MX(GeV)
Geometric (f) Acceptance
x
Dipole ( only)
GeV2
450 400 350 280 200
MX(GeV)
GeV2
Dipole acceptance better at low t, large
x Cross section dominated by low t
x 0 0.02 0.04 1.4 1.4 1.3 2
35 95
7
Roman Pot Castle Design
Worm gear assembly
50 l/s ion pump
Detector
Beam
Step motor
  • Constructed from 316L Stainless Steel at LNLS,
    Brazil
  • Parts are degreased and vacuum degassed
  • Plan to achieve 10-11 Torr
  • Use Fermilab style controls
  • Bakeout castle, then insert fiber detectors

8
Roman Pot Arm Assembly
Detector is inserted into cylinder until it
reaches thin window
Threaded Cylinder
Motor
Bellows
Flange connecting to vacuum vessel
Thin window and flange assembly (NIKHEF)
9
Girder Reconfiguration
Bypass
BEFORE
Sep
Sep
Sep
Sep Girder
Tunnel Floor
Pit Floor
Run I Girder Configuration
AFTER
Bypass
Sep
Sep
Sep
Pot
Pot
Sep Girder
Pit Floor
Hole in Floor
Run II Girder Configuration
10
Castle Status
  • 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.

Quadrupole castle A2 installed in the beam line.
11
Detector Assembly
At the University of Texas, Arlington (UTA),
scintillating and optical fibers were spliced
and inserted into the detector frames.
12
Detectors in Cartridges
The plastic frames containing the clear fibers
are attached to the cartridge bottom (cartridges
built at NIU and UTA).
The cartridge bottom containing the detector is
installed in the Roman pot and then the cartridge
top with PMTs is attached.
13
Tunnel and Detector Status
  • All 18 cartridges have been assembled, 16 are
    installed in
  • tunnel (10 with full detectors 6 with trigger
    scint). The 10
  • instrumented pots (Phase I) are ups, downs, and
    dipoles.
  • Cables and tunnel electronics (low voltage,
    amp/shapers, etc.)
  • installed and operational for full 18 pot
    (Phase II) setup.
  • 10 more detectors (includes 2 spares) are
    complete except for
  • final polishing, which is in progress at
    Fermilab.

14
Veto Counters
In the October 2001 shutdown four veto counters
(designed at UTA, built at Fermilab) each of
which cover 5.2 lt ? lt 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).
15
Pot Motion
Pot 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.
16
Pot Insertion Monitor
Effect of the pot motion on the proton and
antiproton losses at DØ and CDF is monitored
using ACNET.
Current agreement with Beams Division and
CDF requires that the effect on halo rates is
less than 10.
17
Stand-alone DAQ
  • Due to delays in DØ trigger electronics, we have
    maintained our stand-alone DAQ first used in the
  • fall 2000 engineering run.
  • We build the trigger with NIM logic using signals
    given by our trigger PMTs, veto counters, DØ
    clock, and the luminosity monitor.
  • If the event satisfies the trigger requirements,
    the CAMAC module will process the signal given
    by the MAPMTs.
  • With this configuration we can read the fiber
    information of only two detectors, although all
    the trigger scintillators are available for
    triggering.
  • An elastic trigger was formed from coincidences
    of
  • the PUAD spectrometers combined with halo vetoes
    (early time hits) and vetoes on LM and Veto
    counters.

18
FPD Control Room
19
Elastic ?,t (calibrated)
Calibrated ? now peaks at 0
Minimum t about 1.0 Gev2
? peak reasonably Gaussian, still 2x ideal MC
resolution
20
Proton ID
  • The Proton ID group led by Moacyr Souza and
    Sergio Novaes has made substantial progress in
    many software areas
  • Track reconstruction
  • Monte Carlo
  • Unpacking
  • Single Interaction Tool
  • Alignment
  • Database

Regular Proton-ID meetings are held Thursdays
11-1230 in West Wing using VRVS
21
FPD Summary
  • FPD will (soon) be a completely integrated sub-
  • detector of the DØ detector which will help
  • maximize Run II physics potential
  • Hard diffraction exists, but not
    well-understood
  • -- large data samples and precise
    measurements
  • needed
  • Large and L at Tevatron necessary
    for
  • these measurements
  • Combination of quadrupole and dipole
  • spectrometers gives ability to tag both ps
    and p s
  • over large kinematic range, allows alignment,
  • understanding of backgrounds
  • Tremendous progress in installation and
  • commissioning, emphasis currently on
  • trigger, software, operations, and data
    analysis
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