JAN. 2000 Commissioning Run Mark D. Baker
Commissioning ConfigurationMark D. Baker
(+ Park +Olszewski+Katzy +Wozniak + …)
• Purpose of Comm. Run
• Decisions for Comm. Run
• Quality of Full vs CR config.
• Open Issues
• More general year-1 issues
JAN. 2000 Commissioning Run Mark D. Baker
Overview
• 1/2 of 1 Vertex Detector (+Y, +Z)– Choose (+Y, +Z),– It will work. 1 (or 2) full detectors better.
• 1/8 Octagon: arbitrarily choose: MOF*– It will work. Full octagon+rings better.– Do we want a sensor lined up with the spect.?
• Spectrometer: Planes A-E (+partial G??)– A-D necessary, E (or F) exists
• Year 1: Block Spectrometer for a period?
JAN. 2000 Commissioning Run Mark D. Baker
Proposed Vertex Detector
VTA2 VTA3
VTB2 VTB3
VTB6 VTB7
JAN. 2000 Commissioning Run Mark D. Baker
1/2 Vertex works for Z=0->12cm
8101218 16 14
Half VTX Detector
1 Full VTX Detector
(cm)
JAN. 2000 Commissioning Run Mark D. Baker
Eta coverage of Spectrometer vs. Z
Zvtx
JAN. 2000 Commissioning Run Mark D. Baker
Eta coverage of Spect. & VTX.
Zvtx
+Z VTX-Z VTX
JAN. 2000 Commissioning Run Mark D. Baker
Proposed Octagon Configuration
VT**
P***
MOF*
JAN. 2000 Commissioning Run Mark D. Baker
Multiplicity Simulation
True Nch for |<5.3|
Rec. Nch Rec. Nch
Full Octagon + Rings +VTX Commissioning Config.
HIJING Inclusive sample, ZVTX=0
True Nch for |<3.2|
N>3000 (20%)=0.2%=2%
N>3000 (20%)=-0.7%=4.5%
JAN. 2000 Commissioning Run Mark D. Baker
Event-by-event
Full Octagon + Rings +VTX Commissioning Config.
HIJING+PL Central event, ZVTX=0
JAN. 2000 Commissioning Run Mark D. Baker
Proposed Spectrometer Config.
BDF exist
AC can be built from spares.
Build AC!
JAN. 2000 Commissioning Run Mark D. Baker
Spectrometer
• All attempts to find BDF-only tracks in high-multiplicity ER and MC events have failed!
• The various successful spectrometer MC results assume perfect ABCD or more.– Track finding– 3D Vertex Finding– F plane provides redundancy. It exists!
JAN. 2000 Commissioning Run Mark D. Baker
A Central event in PHOBOS
JAN. 2000 Commissioning Run Mark D. Baker
Perfect ABCD w/ VTX
Ghosts @ 2% level
True
Rec.
JAN. 2000 Commissioning Run Mark D. Baker
Perfect ABCD w/o VTX
True
Rec.
JAN. 2000 Commissioning Run Mark D. Baker
B-D-F
• BDF no VTX in MC (min. bias): – Efficiency drops to ~50%, Ghosts increase to ~30%
Real data - Eng. Run
JAN. 2000 Commissioning Run Mark D. Baker
Conclusion
• VTA2-3, VTB2-3, VTB6-7
• MOF*
• P-arm planes: A, B, C, D, F– Build 2 more spare type 1 planes
• Open questions, under active study:– Install MOA7 now? (Judith+Inkyu)– Install MOE6-8 for year 1? (Inkyu)