status of the roman pot project reminder prototyping & testbeam mechanics & infrastructure
DESCRIPTION
Status of the Roman Pot Project reminder prototyping & testbeam mechanics & infrastructure simulation. Hasko Stenzel ATLAS week October 2006. Roman Pots for ATLAS. RP. RP. RP. RP. 240m. 240m. IP. RP. RP. RP. RP. MAPMTs FE electronics & shield. PMT baseplate. - PowerPoint PPT PresentationTRANSCRIPT
Status of the Roman Pot Project
• reminder • prototyping & testbeam• mechanics & infrastructure• simulation
Hasko StenzelATLAS week October 2006
Roman Pot status H.Stenzel, October 2006 2
Roman Pots for ATLAS
RP
IP240m 240m
RPRP RP
RP RP RP RP
PMT baseplate
optical connectors
scintillating fibre detectors glued on ceramic supports
10 U/V planesoverlap&trigger
Roman Pot
MAPMTsFE electronics
& shield
Roman Pot Unit
Roman Pot status H.Stenzel, October 2006 3
testbeam: October 3-18 Purpose:
Verify detector performance observed in 2005 at DESY (6 GeV e- ) with new(larger) detectors, new ATLAS-type electronics with a high energy beam.
New prototypes:
● 10 planes, U&V, 16 fibres tracking ● 2 planes, U&V, 64 fibres final geometry● 2 overlap detectors, 120 fibres each alignment● trigger scintillator elastic L1
Program:
● hit multiplicity & efficiency● cross talk● spatial resolution & homogeneity ● edge sensitivity & active surface ● alignment performance with overlap detectors● trigger efficiency & uniformity
Roman Pot status H.Stenzel, October 2006 4
detector prototypes for testbeam 2006
10 x 2 x 16 resolution studies
2 x 2 x 64 construction studies
2 x 2 x 30 overlaps
Fabrication of prototypes at cern bt PH/DT2 with support from Lisbon (LIP) for fibre machining, aluminum coating, QC testbeam mechanicsand from Giessen for gluing of fibres optical connectors
Roman Pot status H.Stenzel, October 2006 5
QC: Metrology
Fibre ends of 10_2_16after machining at 45º
-136.56
-136.55
-136.54
-136.53
-136.52
-136.51
-136.5
-136.49
1 2 3 4 5 6 7 8 9fibre #
posi
tion
of fi
bre
end
(mm
)
3u3v5u5v6u6v7u7v9u9v10u10v11u11v12u12v
< 20µm variation from one plate to another
prototype 2005:> 250 µm variation
Roman Pot status H.Stenzel, October 2006 6
overlap detector: new technologySection to be bent
Preheat from room temp to 85ºC
Bend fibres at 85ºC
Straight section
A. Mapelli
Roman Pot status H.Stenzel, October 2006 7
trigger scintillator
scintillator
photomultiplier
light guide
New design of trigger scintillator with lightguide
coupled to a PMT.
Roman Pot status H.Stenzel, October 2006 8
electronics: final set-up
fibreMAPMTPMF(MAROC)MotherBoardDAQ
Roman Pot status H.Stenzel, October 2006 9
electronics: testbeam set-up
PMF Build Up for testbeam October
HV boardAdapter board
Active board
MAROC chip
R/O FPGAMAROC R/O chip
R/O FPGA
CERN, Orsay (MAROC) & Lund (PMF & MB)
Roman Pot status H.Stenzel, October 2006 10
The final ATLAS Roman Pot Unit
● Pre-production of one unit at Vakuum Praha
● expected at CERN Oct.31● will be instrumented and tested● review of the tests before
production● possible timescale : 4 units at
CERN April-May 2007
Roman Pot status H.Stenzel, October 2006 11
Pre-production unit
Courtesy of Vakuum Praha
Roman Pot status H.Stenzel, October 2006 12
The final Roman Pot
Overlap extrusions brazed on bottom
Top flange with helicoflex joint
Pumping hole
Rectangular body out of center
Brazing under test S.Mathot (TS-MME)
• Prototyping & production at CERN TS
• Material for prototype & final production arrived Oct.2
• Prototyping Oct/Nov
2006
• final production sync. with Unit procurement
Roman Pot status H.Stenzel, October 2006 13
Infrastructure: Cable installationReminder – cabling list:
Quantity
Name Start End Type /side of IP1 Total
Trigger XRP-240 USA15 FLEXWELL Air Dielectric Cable, HF 7/8"
4 8
Data link + TTC XRP-240 USA15 Optical fiber for data and TTC (9 fibers/side)
2 4
LV power USA15 RRs 3x4CEM 1 2
LV power control USA15 RRs ND36 2 4
LV power RRs XRP-240 2x25CEM 4 8
LV power RRs XRP-240 2x4CEM 4 8
HV USA15 XRP-240 Mulcitonductor HV cable, 3kVdc, 4 8
FE controls USA15 XRP-240 EIA/TIA RS485 4 8
ELMB USA15 XRP-240 VE18CAN-1.0 2 4
Motor control USA15 XRP-240 NG18 2 4
Limit switches USA15 XRP-240 NE26 2 4
Resolver USA15 XRP-240 NE18 2 4
Position sensors USA15 XRP-240 NE48 2 4
Overlap detector trigger
XRP-240 USA15 50Ohm signal 8 16
BPMs XRP-240 RRs CMC50 4 8
Roman Pot status H.Stenzel, October 2006 14
Infrastructure: Cable installation
Installation of all cables through UPS galleries is now completed on both sides of IP1● Access to the UPS galleries is not allowed anymore due to the installation and
calibration of the instruments for the geometers.● HV multiconductor cables are to be installed, different path via US to UX,
depending on the location of HV power supplies (US15)
Air-core cables – min. bending
radius of 250mm respected
Optical fibers
Roman Pot status H.Stenzel, October 2006 15
Q4 polarity switch
RR13 Level 1
RR13 Level 0DFBLA
RQ4.L1B2 RQ4.L1B1
inverter 7kA
Christophe Coupat AB/PO
Switch for Q4 quadrupole to change its polarity when switching from normal to ATLAS/Lumi optics.
Base & cabling are completed. Temporary Cu plates ordered, will be installed soonBuying the switch itself can be done later
Roman Pot status H.Stenzel, October 2006 16
Simulation of the LHC set-up
elastic generatorPYTHIA6.4
with coulomb- and ρ-termSD+DD non-elastic
background, no DPE
beam propertiesat IP1
size of the beam spot σx,y
beam divergence σ’x,y
momentum dispersion
beam transportMadX
tracking IP1RP high β* optics V6.5
including apertures
ALFA simulationtrack reconstruction
t-spectrumluminosity determinationlater: GEANT4 simulation
Roman Pot status H.Stenzel, October 2006 17
Simulation of elastic scattering
2
,
2
,
2
2222*
yeffxeff
yx
Ly
Lxp
ppt
t reconstruction:
hit pattern for 10 M elastic events simulated with PYTHIA + MADX for the beam transport
2
sin
effL
special optics parallel-to-point focusing high β*
Roman Pot status H.Stenzel, October 2006 18
acceptance
Global acceptance = 67%at yd=1.5 mm, including losses in the LHC aperture.Require tracks 2(R)+2(L) RP’s.
distance of closest approach to the beam
radGeVTOT
EMat
NfCf
5.324106
8
|||| :Region Coulomb
Detectors have to be operated as close as possible to the beam in order to reach the coulombregion!
-t=6·10-4 GeV2
decoupling of L and σTOT only via EM amplitude!
Roman Pot status H.Stenzel, October 2006 19
t-resolution
The t-resolution is dominated by the divergence of the incoming beams.
σ’=0.23 µrad
ideal case
real world
2*231
ˆ pppt
Roman Pot status H.Stenzel, October 2006 20
L from a fit to the t-spectrum
2
222/
2
22
2
1614
ce
te
tcL
FFLdtdN
tBtot
tBtot
NC
input fit error correlation
L 8.10 1026 8.151 1026 1.77 %
σtot 101.5 mb 101.14 mb 0.9% -99%
B 18 Gev-2 17.93 Gev-20.3%
57%
ρ 0.15 0.143 4.3% 89%
Simulating 10 M events,running 100 hrsfit range 0.00055-0.055
large stat.correlation between L and other parameters
Roman Pot status H.Stenzel, October 2006 21
experimental systematic uncertainties
Currently being evaluated
beam divergence detector resolution acceptance alignment beam optics
ΔL/L ≈ 1.9-2.1 %
missing: background studies (are under way)
total error ≈ 2.6-2.8 %
Roman Pot status H.Stenzel, October 2006 22
conclusion
● testbeam 2006 is starting, preparations in full swing
● new prototypes produced, including overlaps and trigger
● electronics set-up close to ATLAS
● RP units and pot prototypes are under production
● major cable installation effort ● progress on simulations for TDR