me0 stack options
DESCRIPTION
ME0 stack options . In Shashlik and CFCAL HE designs, space of D z~36 cm exists behind 10 lambda for muons An ideal ME0 detector geometry has been inserted and is being used for simple muon studies - PowerPoint PPT PresentationTRANSCRIPT
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ME
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UC
LA
In Shashlik and CFCAL HE designs, space of Dz~36 cm exists behind 10 lambda for muons An ideal ME0 detector geometry has been inserted and is being used
for simple muon studies
On the other hand, in HGCAL, a tail catcher of hadron showers is currently implemented as potentially dual purpose with ME0 muon detection In fact this design is not being used for muon reconstruction yet
Some thoughts following conversations with Valeri Andreev, Roger R, Marcello M, Archana, Karl Gill, Alain Herve, Pawel…
ME0 stack options
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Baseline proposed at ECFA workshop Oct. 2013 ME0 covers eta 2.0 to as high as possible (<4.0) within
endcap
High Rapidity Muon (HRM) layout
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Support of HE mechanical load and moment:Nose engineering drawing
3
Ser
vice
s &
Sup
port
Bolts at outer radius
Sliding joint to strong back at inner radius
Transfer load from HE over ME0 chambers here
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Current GE1/1 design: 44mm for each layer includes electronics, services 88mm for 2 layers – too thick for ME0 6 layers
Short (high-eta) ME0 design allows for central readout board Try for 50mm or thinner for 2 layers
GEM chamber thickness
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Version A) Shashlik and CFCAL sims: 6x1 layer chambers, no segmentation in
phi (ideal but unfeasible in reality)
Simulation ME0 “stack” cartoons Version B) HGCAL sim:
4x1 layer chambers, 0.47 l and 5.1 X0 between measurements
HE tail catcher between 9.5-11 l
~36
cm?
muon
~23 cm
~4 cm
1-layer, 2*p chambers
2.5 borated polyethylene1.2 Pb for n shielding
0.90 cm3.45 cm0.90 cm
…
34.8
cm
Brass absorberBrass spacer
3.45 cm
Brass absorberBrass spacer
5
~4 cm
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ME0 version A (Shashlik, CFCAL)
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From VirdeeEuroschool 2003… tail catching
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Cartoon rotated to match the orientation of engineering drawings
Version C) 2-layer units convenient for construction (similar to GE1/1)
20-degrees/chamber in phi, 2-chamber units offset by 6.67 degrees Assures 4 or more hits at all f , given
the dead space between abutting chambers
Absorber in between (4 cm) improves tail catcher function
Variant of ME0 stack that staggers 2-layer units
8
4 cm 4 cm9 cm
Dz = 35 cm
2.5
bora
ted
poly
ethy
lene
plu
s 1.
2 P
b fo
r n s
hiel
ding
2.5
bora
ted
poly
ethy
lene
plu
s 1.
2 P
b fo
r n s
hiel
ding
Abso
rber
m c
ham
ber
etc.
→
etc.
→
etc.
→
f di
rect
ion
→
9 cm 9 cm
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ME0 is used for muons to link to inner Tracker tracks
Especially at highest eta, Tracker uses endcap pixel disks Error ellipse is therefore likely to be rather round
Squarish pads, therefore, are better for matching than narrow strips This also favors use as a tail catcher in a projective
calorimeter But ignores the possibility of modest rejection
of low-Pt muon candidates Skinny radial strips best for this Studies are needed to identify the dominant effect?
Finally, ME0 segmentation
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Should install version A stack in HGCAL sim ASAP HE: tail catcher capability doesn’t see to be high
priority for studies, HGCAL group has expressed their flexibility
“Give” or at least “lend” the 34.8 cm space in z to the muon community for optimization Z= 5193 – 5541 mm in present HGCAL (V.Andreev
layout)
Expect more detailed discussion at GMM in 2 weeks
Conclusions - suggestions
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Backup slides
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Version C) 2-layer units convenient for construction (similar to GE1/1) 20-degrees/chamber in phi, 2-chamber units offset by 6.67 degrees
Variant of ME0 stack that staggers 2-layer units
12
4 cm
4 cm
9 cm
Dz =
35
cm
2.5 borated polyethylene1.2 Pb for n shielding
2.5 borated polyethylene1.2 Pb for n shielding
Spacer/ absorber
Spacer/ absorber2-layer m , 20-degrees
2-layer m , 20-degrees
Spacer/ absorber
Spacer/ absorber2-layer m , 20-degrees
2-layer m , 20-degrees
Spacer/ absorber2-layer m , 20-degrees
Spacer/ absorber
2-layer m , 20-degrees
Spacer/ absorber
2-layer m , 20-degrees
Spacer/ absorber2-layer m , 20-degrees
etc.→
etc.→
etc.→
f direction →
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From the TDR of the HCAL
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Version D) 3x2 layer chambers, 0.54 l and 6.0 X0 between chamber measurements
Other possibilities Version E) 2x 3 layer
chambers, 0.77 l and 8.6 X0 between chamber measurements
2.3 cm
3.4 cm
2.3 cm …
34 c
m
3.4 cmBrass absorber
Brass spacer
Brass absorber
Brass spacer
2-layer m
2-layer m
4.0 cm
4.5 cm
4.0 cm
…
4.5 cm
34.2
cm
3-layer m Brass spacer
Brass absorber
3-layer m Brass spacer
Brass absorber
3-layer m Brass spacer
Brass absorber
3-layer m Brass spacer
Brass absorber
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D (3 x 2layer chambers) Pros Familiarity with 2-layer
packages from GE1/1 etc Pretty good HE tail
catcher Cons Thicker brass spacers –
is it a mechanical problem?
Comments on Versions D and E
E (2 x 3layer chambers) Pros Muon radiation isolation
between successive chambers (more X0 in brass, is it enough?)
Fair HE tail catcher Cons Unfamiliar package Even thicker brass
spacers – is it a mechanical problem?
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Brass density 8.4-8.73 (casting, rolling variations) Composition 63% Cu and 37% Zn by weight At 8.4, density of Cu=5.292 g/cm3, density of Zn
3.108 g/cm3 At 8.73, reduce interaction and rad lengths by
3.93%
Interaction lengths, radiation lengths Cu l=137.3 g/cm2, X0=12.86 g/cm2 Zn l=138.5 g/cm2, X0=12.43 g/cm2
Interactions add up weighted average of the r/l and r/X0
For 63/37 brass, calculate l=16.4 cm, X0=1.511 cm
Behind the calculations
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Valeri 1.0 l for EE 0.3 l for EE stainless
back 4.0 l for Si-brass 4.15 l for Scint-brass
9.45 l in front of GEM 1.85 l for GEM-brass
Valeri vs. my l calculationsMe: 1.0 l for EE (take as a
given) 0.3 l for EE stainless
back 3.9-4.07 l for Si-brass 4.28-4.45 l for Scint-
brass
9.48-9.82 l in front of GEM (or 0.03-0.37l higher)
1.90-1.98 l for GEM-brass
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(0, 5, 10, … cm)Stack cartoon ruler
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0
10
5
20
30
40
15
25
35