Main Changes to the FT description:

Should be a TWiki page, extend knowledge of experts to others, include links

Zip file of material information brochures and MSDS: MaterialsSafety.zip

Right-click -> 'View Image' to view larger image, or download the link from the bottom

Panel Materials:

  • correct thicknesses and core materials(Oliver, Blake)
  • realistic mats (Dortmund and Aachen to measure and weigh a produced mat), five layer and six layer mats
  • panelassembly_sideview.pdf: panelassembly_sideview.pdf
  • layers should be combined to reduce number of volumes, most materials have radiation lengths of ~40 g/cm2. i.e. incorporate the glue layers into the carbon fibre skin.
  • 2 x 2mm endpiece material should be added at the y=0 region and around the beam pipe. See drawings below.

Material Thickness (μm) Layers X0/ρ (cm) X/X0 (%)
Core(Nomex/Airex/Divinycell*) 20000 2 1750/689/1050 0.229/0.580/0.381
CFRP skin 200 2 27.56 0.145
Panel glue 75 4 34.9 0.083
Fibre mat(w/TiO2) 1450 +30/-100 (6 layers) 1 33.2 0.437+0.01/-0.03
Casting glue(w/o TiO2) 100 2 34.9 0.055
Total y>2cm 4235     0.95/1.3/1.1
Polycarbonate 2000 2 41.46 0.965
Total y<2cm** 4235     1.79/2.11/1.93

*Divinycell is the preferred option for now

**core and casting glue are removed to accomodate endpiece

scifilayers.png

Elements and material radiation lengths

(taken from slides: Physics IB RWTH Aachen, A. Schultz v. Dratzig):

X0 g/cm2 = 716.4*A/(Z(Z + 1)*ln(287.0/sqrt(Z)))

Element X0(g/cm2)
H 63.047
C 42.70
N 37.99
O 34.24
F 32.93
Ti 16.17

1/X0 = Σnj/X0j

Material Composition X0 g/cm2 Density (ρ) g/cm3 X0/ρ cm
Epoxy C27 H32 O4 N2 41.87 1.2 34.89
Polycarbonate   41.46 1.2 34.6
Airex R82.60 C37 H24 O6 N2 41.35 0.060 689.13
Divinycell F40 Airex-like 42.0 0.040 1050
Nomex A1-24-6 C14 H10 O2 N2 + C8 H12 O2 42.0 0.024 1750
CFRP 60%(68.75%)Fibre/40%(31.25) Epoxy by volume(weight) 42.44 1.54 27.56
SciFi Mat w/TiO2 Double clad 39.18 1.18 33.23

Epoxy = Bisphenol-A C15 H16 O2 + 2 Epichlorohydrine C3 H5 Cl O = C21 H26 O4 Cl2 + NaOHNaClH2O = C21 H24 O4 + Diaminobenzol C6 H8 N2 = C27 H32 O4 N2 X0 = 41.87 g/cm^2 = 34.89 cm

Radiation Length of SciFi Mat:

  • Polystyrene 58.58 % mass
  • PMMA 4.32 % mass
  • Fluorinated Polymer 5.32 % mass
  • TiO2 7.94 % mass
  • Epoxy 23.84 % mass
  • X0 = 39.18 g/cm^2
    • = 33.23 cm

Geometry

Notes:

  • a higher resolution pdf of the sketches below is here panelassembly.pdf: panelassembly.pdf
  • triangles stay as is (no horizontal y=0 cut); impact on efficiency being evaluated first
  • Additional dead material at fibre mat edges
    • (0.125mm of dead fibre at each outer edge of the fibre mat + 130.2mm of active fibre to match SiPM active width of 4 arrays) = 130.45 total mat width
    • 0.150 mm between fibre mat edges = 130.60 mm centre-to-centre of adjacent mats; likely will be filled with epoxy resin during production.
  • Module widths to match SiPM gaps and widths (522.4mm outer width of modules in X, stereo too)
  • Layer position in z remains the same
  • Beam pipe cut-out should be studied. Someone needs to find the optimal cutout. Will use SiPM array widths (32.650mm c-to-c as horozontal cut width. Step height will be determined by beam-pipe radius per station.) for now until optimal pattern is studied.
    5mmodule_lengthwidth.pngpanel.png

Beam-pipe region

  • scifi beampipe layout:
    scifilayers_beampipe.pngscifilayers_zoomout.png
Table from https://lhcb-background.web.cern.ch/lhcb-background/BeamPipe/Drawings/August2007/Table-20070808.htm Last edited by G. Corti 6-Mar-2006
Component Detail Zstart Zend Length Inner Inner Thickness Outer Height Outer Theta
  Dz Radius Diameter ( c ) Radius (d) Diameter (d2)
  [mm] [mm] [mm] (a) [mm] (b) [mm] [mm] (a1) [mm] [mm] [mm] [mrad]
Conical section see Split4 7500.05 8300.05 800.00 75.00 150.01 1.60 76.60 153.21 10.00
Conical section 8300.05 8700.05 400.00 83.00 166.01 1.70 84.70 169.41 10.00
Conical section 8700.05 9500.05 800.00 87.00 174.01 1.90 88.90 177.81 10.00
Conical section 9500.05 10300.05 800.00 95.00 190.01 2.00 97.00 194.01 10.00
(a) Inner radius of the beam pipe for cones at Zstart
(a1) Outer radius = Inner radius + radial thickness for pipes (approx with thickness when calculated)
  inner radius + height for flanges and bellows
(b) Quoted for convenience
(c) This is the thickness for the pipe wall. Details for the bellows are quoted separately in the additional table just above.
(d) This value is valid only ffor flanges and refers to their radial dimension
(d2) For flanges the angle applies only for the inner wall, the outer wall has 0.0 angle


BeampipeT1_20.pngBeampipeT2_20.png BeampipeT3_20.png

Station ZCentre ZLast-edge bp radius (e) bp thickness buffer module diam.
  [mm] [mm] [mm] (e) [mm] (f) [mm] (g) [mm] (h)
T1 7948 8061.2 80.61 1.67 20 204.6
T2 8630 8743.2 87.43 1.91 20 218.7
T3 9315 9428.2 94.29 1.99 20 232.6
(e) inner beampipe radius at the last station edge
(f) beam pipe thickness at last station edge
(g) buffer is an estimated nominal value for now (May 27, 2014); will be updated in the future
(h) station cutout to accommodate the beampipe including the 20mm buffer radius

Digitization

  • Photo Detector spacing (Diego, Guido)
    • A SiPM array consists of (from left to right) 0.170 mm inactive edge + 16.00 mm 64ch active + 0.250 mm inactive gap + 16.00 mm 64ch active + 0.170 mm inactive edge = 32.59 mm total package width
    • SiPM arrays are spaced 0.060mm apart such that adjacent SiPM arrays are 32.650mm centre-to-centre
    • Dead spaces dues to inactive regions are then either 0.250 mm between 64chs, or 0.400 mm between neighbouring arrays (0.170mm +0.060mm +0.170mm)
    • Modules are nominally spaced 3mm apart, same as the OT. Inactive regions between modules are then 3mm + 0.400 mm = 3.400 mm
    • A fibre mat is 0.125 inactive material + 130.2mm active + 0.125 inactive material from left to right. The active material aligns with the outermost active channels of 4 SiPM arrays
    • The gaps between fibre mats with a module align with the space between active SiPM arrays. 0.125mm inactive material + 0.150 mm gap + 0.125 mm inactive material = 0.400 mm
beampipecutoutandgaps.png

Module Spacing (mm) Geometrical Coverage by SiPMs
0.0 98.0%*
1.0 97.8%
2.0 97.6%
3.0 97.4%
4.0 97.2%

* there is a total of 10.4 mm of gaps (16*0.4mm + 16*0.25 ) within the 522.4mm SiPM length in a module.

  • Attenuation and radiation maps: parameterisation or tables. Needs to be explainable to other people in code, documentation or something.
    • number of direct photons detected per MeV deposited (light yield, spectra, quantum efficiency, attenuation due to radiation, 0--50fb-1)
    • number of reflected photons detected per MeV deposited (" ")
  • Check geometrical efficiency not included in hit detection efficiency
  • Light sharing and clusterisation:
    • cosmic, Sr90 source(perpendiculer) vs Nikhef simulation(larger angular acceptance), equation that models multiplicity better
    • *tails in the energy deposition, Birk's saturation, efficiency in low p.e. side; tune detailed GEANT mode
  • Fluctuations: check for double application(smearing) of effects
  • Noise model: all parameters need to be checked. Update and verify model i.e.
    • Crosstalk percentage is currently 7%
    • Afterpulsing is currently 15% probability, check temperature dependence of time constants and effect on spillover
    • Dark count rate changes with overvoltage (proportional to volume of silicon in the depletion region)
    • Check Thermal dark count rate (unirradiated) 100kHz?
    • Check that damage with dose is correct
  • Spillover
    • Check with electronics people that the time dependant signal amplification is correct (currently only simulation)
HC: It is not correct (it has been done only with the Hamamatsu SiPM model with an incomplete simulation model). New simulations have to be performed and checked with the real hardware.
    • Optimization of t_0 needed to balance spillover?

Monte Carlo Sample Priority

Yasmine will add her table

  • Additional geometric configurations: bilayer, y-segmentation will get lower priority over baseline detector studies.
Topic attachments
I Attachment History Action Size Date Who Comment
PDFpdf 128ch-MPPC-small_gap-1.pdf r1 manage 319.3 K 2014-04-08 - 16:55 BlakeLeverington  
PNGpng 5mmodule_lengthwidth.png r2 r1 manage 81.2 K 2014-04-09 - 13:51 BlakeLeverington  
PNGpng BeampipeT1.png r2 r1 manage 267.5 K 2014-05-14 - 14:50 BlakeLeverington BeampipecutoutT1
PNGpng BeampipeT1_20.png r2 r1 manage 237.9 K 2014-05-16 - 16:13 BlakeLeverington BeampipecutoutT1
PNGpng BeampipeT2.png r1 manage 287.6 K 2014-05-14 - 14:51 BlakeLeverington BeampipecutoutT2
PNGpng BeampipeT2_20.png r2 r1 manage 263.7 K 2014-05-16 - 16:14 BlakeLeverington BeampipecutoutT2
PNGpng BeampipeT3.png r1 manage 247.8 K 2014-05-14 - 15:50 BlakeLeverington BeampipecutoutT3
PNGpng BeampipeT3_20.png r2 r1 manage 256.5 K 2014-05-16 - 16:14 BlakeLeverington BeampipecutoutT3
Compressed Zip archivezip MaterialsSafety.zip r1 manage 2671.9 K 2014-04-14 - 15:57 BlakeLeverington  
PNGpng beampipecutoutandgaps.png r3 r2 r1 manage 127.8 K 2014-04-10 - 10:57 BlakeLeverington  
PNGpng panel.png r3 r2 r1 manage 225.7 K 2014-04-10 - 10:58 BlakeLeverington  
PDFpdf panelassembly.pdf r1 manage 488.6 K 2014-04-10 - 10:59 BlakeLeverington  
PDFpdf panelassembly_sideview.pdf r1 manage 74.1 K 2014-04-08 - 09:55 BlakeLeverington  
PNGpng scifilayers.png r2 r1 manage 20.4 K 2014-04-10 - 16:59 BlakeLeverington  
PNGpng scifilayers_beampipe.png r1 manage 68.5 K 2014-05-05 - 17:48 BlakeLeverington scifi beampipe layout
PNGpng scifilayers_zoomout.png r1 manage 66.1 K 2014-05-05 - 17:49 BlakeLeverington scifi layer position
PNGpng stereobeampipecutout.png r1 manage 46.1 K 2014-04-08 - 10:38 BlakeLeverington  
Edit | Attach | Watch | Print version | History: r23 < r22 < r21 < r20 < r19 | Backlinks | Raw View | WYSIWYG | More topic actions
Topic revision: r23 - 2018-11-27 - BlakeLeverington
 
    • Cern Search Icon Cern Search
    • TWiki Search Icon TWiki Search
    • Google Search Icon Google Search

    LHCb All webs login

This site is powered by the TWiki collaboration platform Powered by PerlCopyright & 2008-2020 by the contributing authors. All material on this collaboration platform is the property of the contributing authors.
Ideas, requests, problems regarding TWiki? Send feedback