FPD STATUS

1
FPD STATUS

• JORGE MOLINA
• CBPF
• February 2002

2
Detector Installation

• 10 detector cartridges have been installed
• 8 in the vertical plane, 2 at Dipole
  locations
• We expect to install the remaining 8 in the
• July 2002 shutdown

Z(m)
3
Castle Status

• All 6 castles with 18 Roman pots comprising the
  FPD were constructed in Brazil and have been
  installed in the Tevatron in fall of 2000.

Quadrupole castle A2 installed in the beam line.
4
Detector Setup
Six planes (u,u,x,x,v,v) of 800 mm
scintillating fibers () planes offset by
2/3 fiber
20 channels/plane(U,V)() 16 channels/plane(X,X)
112 channels/detector 18 detectors 2016 total
channels 4 fibers/channel 8064 fibers 1 250 mm
LMB fiber/channel 8 LMB fibers / bundle 252 LMB
bundles 80 mm theoretical resolution
U
U
4 fiber bundle fits well the pixel size of H6568
16 Ch. MAPMT (Multi- Anode Photomultiplier
Tube) 7 PMTs/detector 16 250 mm fibers each PMT
5
Detector Assembly
At the University of Texas, Arlington (UTA),
scintillating and optical fibers were spliced
and inserted into the detector frames.
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Detector Mapping
After the detectors were assembled and polished,
an optical scanner was used to map the exact
location and width of the fibers in the frames
to improved detector calibration.
7
Detector Cartridges
The two-part cartridge houses the detector and
phototubes and allows for easy access to PMTs.
The Cartridge top fits over the bottom and is
secured down causing good contact between the
tubes and frames
8
Detectors in Cartridges
The plastic frames containing the other end of
the fibers are attached to the cartridge bottom.
The cartridge bottom is installed in the
tunnel and the detector is pushed to the bottom
of the pot.
9
Installed Cartridge
A2 station with cartridges mounted in the
vertical plane
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Cartridge Status

• All 18 cartridges are assembled. Ten cartridges
  are installed
• 6 of them are in their final configuration
• P1D, P2D, A1D,A2D,D1 and D2
• 2 of them contain prototype detectors P1U
• and P2U. Prototype detectors are the first
• detectors produced and not of high quality
• as later ones (we will keep them as spares)
• 2 of them are pseudodetectors (trigger
• scintillators only) A1U and A2U
• All the MAPMTs and L0 detectors were
• grouped according to their characteristics
• In February the installation of the remaining
  four detectors of Phase I will be completed

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VETO COUNTERS
In the October shutdown four veto counters each
of which cover 5.2 lt ? lt 5.9 were installed
between DØ and the quadrupoles, about 6 m from
the interaction point.
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The counters, two each on the outgoing proton
and anti-proton arms, can be used to trigger on
rapidity gaps.
13
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.
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Detector location
LVDT (Linear Voltage Displacement
Transducer) connected to the castle measure the
actual pot displacement and return values giving
the distance from the Home position of each
pot.
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Pot Motion Safeguards

• The software is reliable and has been tested
  extensively. It has many safeguards to protect
  against accidental insertion of the pots into the
  beam.
• The drivers are disabled with a switch in the
  Control Room when the pots are not being moved.
• The pots are hooked to an emergency line which
  bypasses the software to send the pots back to
  the home position in case of
• emergency (tested but not used).

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Pot Insertion Monitor
Effect of the pot motion over the proton and
antiproton losses at D0 and CDF
We should not affect the losses more than 20
under the risk of make the beam unstable
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FPD BLOCK READOUT AND TRIGGER CHAINS
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Standard DAQ
We are working on commissioning the standard Run
II DAQ. The most recent progress was the
construction and installation of the Transition
Patch Panel and combs.
We are working on the DFE FPGA logic and awaiting
our complement of AFE boards, integration with DØ
is scheduled over the next 3 months.
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STAND-ALONE DAQ

• Due to delays in DØ trigger electronics,
• we have maintained our standalone 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
  information of only two detectors (currently PD
  spectrometer is read out).

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View of the Small Control Room used for
the Standalone DAQ
21
Elastic Trigger Logic
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Plateau Curves
The Trigger Scintillators were plateau using
elastic events in a three fold/four fold basis
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Problems
A problem we had in the tunnel was due to noise
caused by the (WWII surplus) low voltage power
supplies used for the amplifier boards. They
induced a current in the cables that added an
extra peak in pedestal distribution.
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and Solutions

• The problem were solved by adding a new rack at
  each pot station in the tunnel with new high
  quality LVPS and isolation transformers (this
  configuration also isolates Tevatron and DØ noise
  sources).

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RESULTS
Elastic ADC Distribution
Spectra for plane U in the detector P2D
with Pedestal subtraction and TDC cuts
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Hit distribution for detector 1 plane by plane
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Multiplicity distributions per each plane in
both detectors
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Total multiplicity both detectors and event
Selection that satisfies the requirements
of Having at least 3 hits per detector
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Hit Reconstruction
This event (from Engineering Run data)
represents a hit in our detector at the
location xd 5.6 mm yd 3.8 mm
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SOFTWARE UPDATE

• The principals advances in Software development
  were made in
• Unpacking
• Tracking
• Single Interaction Tool
• Alignment
• Gap Tool
• Database

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Plans and Milestones
Take more data with Stand Alone DAQ with this
configuration, then switch detectors to readouts
(still for elastic events) Take diffractive
data. TM operational 1/31/02 AFE installed
3/1/02 Firmware and Trigger development FPD
data with 10 pot system 4/1/02 Prepare for the
July shutdown installation of the horizontal
plane
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CONCLUSIONS

• Tremendous progress in installation and
  commissioning
• Entering a new FPD era Installation of Phase I
  complete
• Emphasis shifts to software, operations,
  and data analysis
• Trigger hardware and firmware still a major
• concern
• Starting to think about physics a little!

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Current FPD Group

• Alberto Santoro (co-leader, UERJ)
• Andrew Brandt (co-leader, UTA)
• Mike Strang (UTA)
• Pierrick Hanlet (UTA)
• Christophe Royon (Saclay)
• Victor Bodyagin (Moscow State)
• Mike Martens (FNAL)
• Sergio Novaes (IFT/UNESP)
• Jorge Molina (CBPF)
• Gilvan Alves (CBPF)
• Helio da Motta (CBPF)
• Newton Oliveira (UFBA)
• Eduardo Gregores (IFT/UNESP)
• Mario Vaz (CBPF)
• Jorge Barreto (UFRJ)
• Vitor Oguri (UERJ)
• Carley Martens (UERJ)
• Marcia Begalli (UERJ)

(based at FNAL)