955e66e267a6d0314e52ff931050e0fa.ppt
- Количество слайдов: 18
FPD Status and Data Quality Bellows Andrew Brandt UTA Roman Pot p p Detector P 1 UP P 2 OUT S D D 2 D 1 59 57 Q 2 Q 3 Q 4 A 2 23 S P 1 DN A 1 33 Q 4 Q 3 Q 2 0 23 P 2 IN 33 Z(m) DØ Workshop June 17, 2003 Beaune, France
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. A 2 U pot had vacuum leak and was disabled for 6 months and fixed during Jan. 2003 shutdown. A 2 Quadrupole castle installed in the beam line.
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 17. 39 mm V’ V Trigger X X’ 17. 39 mm U’ U 8 0. m 1 m m m 3. 2 mm • U and V planes have 20 fibers, X planes have 16 fibers • Planes in a frame offset by ~2/3 fiber
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.
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 (Q 4), 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).
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.
FPD Trigger and Readout
FPD Integration Substantial, if not speedy, progress (stand-alone DAQ in parallel) I) AFE 1) 2) 3) 4) 5) 6) 7) 8) 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 1) Boards in hand 2) 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
Elastic Data A 1 U A 2 U LM VC Pbar Halo Early Hits P In-time hits in AU-PD detectors, no early time hits, or LM or veto counter hits P 1 D P 2 D ØApproximately 3 million elastic triggers taken with stand-alone DAQ ØAbout 1% (30, 000) pass multiplicity cuts –Multiplicity cuts used for ease of reconstruction and to remove halo spray background
Elastic Data Distributions Before alignment After alignment Gaussian fit t distribution 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 Ge. V 2; tmin is determined by how close the pots are from the beam, shape is in rough agreement with expected angular acceptance from MC.
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!) D 2 TDC pbar p m y ar in DØ eli r P D 1 TDC
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)
Software Status • Monte Carlo Tools – MC for Diffractive Physics (POMPYT, POMWIG, SCIPYT): released – FPD is fully integrated in DØg. Star: – FPD geometry + beamline in DØg. Star + DØSim FPDDigi. Chunk • L 3 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
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
Missing Software • • Integration of FPD_Reco into DØReco Trigger Simulator: Raw Data L 3 Geometry: Offline DST & TMB Info: DØReco FPD_Analyze: Offline (DST+TMB) Alignment Tool (offline): Elastic stream Calibration Tool (offline): LMB + Data
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
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 50 -100 times worse, due to neglected single pass halo generation term 10 or worse Effects: 1) acceptance for quad spectrometers drops by x 3/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 (D 0 PHTL) and A-halo (D 0 AHTL) show that 35 k. Hz and 2. 5 k. Hz respectively give tolerable rates (routinely exceeded) Working with BD on detailed plan for halo study and rejection
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: Ø Ø 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!
955e66e267a6d0314e52ff931050e0fa.ppt