1. FPD Status and Data Quality Andrew Brandt
UTA Q4 D S Q3 A1 A2
P1UP p
Z(m) D1
Detector
Bellows
Roman
Pot 23 33 59 57
P2OUT Q2
P1DN
P2IN D2
DØ Workshop June 17, Beaune, France

2. installed in the beam line.
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 shutdown.
A2 Quadrupole castle
installed in the beam line.

3. FPD Detector
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
17.39 mm V’ V
Trigger X’ X U’ U
17.39 mm
1 mm
0.8 mm
3.2 mm

4. Tunnel and Detector Status
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.

5. Veto Counters
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).

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

7. FPD Trigger and Readout

8. FPD Integration
Substantial, if not speedy, progress (stand-alone DAQ in parallel)
I) AFE
Added FPD AFE’s, Sequencer, and VRB to CFT database
Modified sequencer for FPD timing
Modified AFE firmware for FPD timing
Built and extensively tested transition board (TPP) between
detector cables and flex cables
Overcame several installation difficulties
Updated FPD AFE packing code
Created FPD examine
2 Boards installed, commissioning in progress
II) DFE
Boards in hand
Trigger equation firmware being tested in combined test stand
III) LM electronics to read out trigger scintillator
and for FPD trigger
IV) TM
1) Components installed, cables laid, commissioning ready to begin

9. Elastic Data Halo Early Hits
A1U
A2U
P2D
P1D P
Pbar
Halo Early Hits LM VC
In-time hits in AU-PD detectors, no early time hits, or LM or veto counter hits
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

10. Elastic Data Distributions
After alignment correction,
x peaks at 0 (as expected
for elastics); MC x
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.
Before
alignment
After
alignment
Gaussian
fit
t distribution

11. Dipole Data Timing
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!)
pbar
D2 TDC p
DØ Preliminary
D1 TDC

12. FPD Operations
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)

13. Software Status Monte Carlo Tools L3 Tools Offline 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

14. FPD Runs Database
Goal: access information about FPD experimental setup
and accelerator conditions which is available
through EPICS during reconstruction & analysis
of data
In progress

15. Missing Software Integration of FPD_Reco into DØReco
Trigger Simulator: Raw Data
L3 Geometry: Offline
DST & TMB Info: DØReco
FPD_Analyze: Offline (DST+TMB)
Alignment Tool (offline): Elastic stream
Calibration Tool (offline): LMB + Data

16. Getting to the Physics Partial list of steps needed to get to physics
quality 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

17. Halo
Operating position determined by halo: either 10% affect on DØ halo, or rates in our pots >180 khz. Beams Division simulations indicated 8-9 feasible. Reality times worse, due to neglected single pass halo generation term  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

18. Summary and Plans
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!
Elastic cross section is used in measurement of luminosity (discrepancy between D0 and CDF)