Straw man for ATLAS ID
for SLHC
David Lissauer – Brookhaven National
Lab.
This layout is a result of the discussions
in the GENOA ID upgrade workshop.
Aim is to evolve this to include list of
questions we need to address in the
simulation and R&D and establish a
baseline
TC
Straw man Barrel Layouts
 b-layer integrated to the beam pipe.
1 layer at
Granularity
Z
R= 5 cm.
300m x 50 m
2x40 cm
2 additional layers at
Granularity
Z length
R=12, 18 cm
400m x 50 m
2x 40 cm

3 layers at
R=27,38,50 cm 4 Layers (27,38,49,60)

Granularity
Z length
3.5 cm x 80 m
2x100 cm
2 Layers
Granularity
Z length
R= 70,95 cm
9 cm x 80 m
2x190 cm



 Inner Layers - Pixels



 Middle Layers

 Outer Layers



4 Layers (75,95)
Straw man End-cap Layouts
 Discs




7 discs
Pixel:
SS:
LS:
Z= 50, 75
Z= 120,165
Z= 210,260,320
4 layers 120,165,180
 Coverage in h

Assume coverage up to 2.5
 Moderator

Left ~ 8-10 cm along the Barrel for moderator
The main difference between the two options is if one has 3 or 4 SS
layers and 6 or 7 Discs. This will depend at the end on the optimization
of the overall detector.
Projective vs. “fixed” length Barrel


“Fixed length”: All the layers in same R region
have the same length in Z.
Projective – each layer can have different length.
Projective:
Fixed Length:
•Smaller Si Area
•Easier assembly
•Material – needs detail
engineering to comment if can be
an advantage.
•Significant less Engineering
•“Fewer” special components
e.g. fewer stave flavors.
Straw man:
Fixed Length Barrel
Independent vs. Integrated Pixel

Independent : Insertion “tube” as in ATLAS.

Integrated : only “b-layer” attached to beam- pipe
Independent Pixel:
Integrated Pixel:
•Schedule of the more complicated
system is decoupled from the large
area detector.
•Less material?
•Services routed at lower h
•Better chance for common system
•One cooling system
•One Heat shield
Straw-man: b-layer with the beam pipe, 2,3rd layer integrated with the Barrel.
Layout Optimization Questions:
1.
# of SS Layers: There are a number of options that need to
be investigated.
3+3+4 : “Intermediate solution”
3+4+2 : Minimal solution – “robust middle section”
3+3+4 : Robust outer section. (Middle section 1D
information only)
1.
# of SS Discs: Number of Discs can vary between 6-7.
Need to be matched to the Barrel.
3.
2D information: There is a question of how many of the
layers need to have 2D information.
One option is that the SS are short enough and there is no
need for Z information.
3.
ID Straw-man Layout (3 SS layers)
ID Straw-man Layout (3 SS layers)
3 Pixel Layers
14,32,48 f Sectors
5,12,18 R Location
3 Short strip layers
22,32,40 f Sectors
27,38,50 R Location
2 Long Strip layers
28,42 f Sectors
70,95 R Location
Moderator
ID Straw-man Layout (4 SS layers)
ID Straw-man Layout (3 SS layers)
3 Pixel Layers
14,32,48 f Sectors
5,12,18 R Location
4 Short strip layers
22,32,40,48 f Sectors
27,38,49,60 R Location
2 Long Strip layers
32,40 f Sectors
75,95 R Location
Moderator
Summary – Si Area
Barrel
Area
Configuration
Total - U
Disc Area only
Total U+V Total
DS
U+V SS
Strawman ID Layout
Pixel
SS
LS
72.49
1.89
14.45
56.15
6.04
0.17
2.85
3.02
78.53
2.06
17.30
59.17
137.69
2.06
17.30
118.33
154.99
2.06
34.60
118.33
Modularity – Installation Sequence
 Surface Assembly of the Barrel


Assemble as much of the Barrel as possible.
In this version we assume that we can assemble part of the
disks already on the surface – this needs detail Eng. Studies.
 The installation sequence of ID in the pit.

Step I:
Step II:
Step III:
Step IV:
Step V:
Moderator and services on IWV
Barrel Surface assembly
Barrel Services (cables, pipes)
Outer Discs
Outer Discs services

Step VI:
b-layer + beam pipe




Surface Assembly –
Step 1
Surface Assembly –
Step 2
Surface Assembly –
Step 3
Surface Assembly –
Step 4
Surface Assembly –
Step 5
Surface Assembly –
Step 6
Surface Assembly –
Step 7
Surface Assembly –
Step 8
Ready to Transport to the Pit
Assembly in the pit–
Step 1
Assembly in the pit–
Step 2
Assembly in the pit–
Step 3
Assembly in the pit–
Step 4
Assembly in the pit–
Step 5
Assembly in the pit–
Step 6
“Stave” Concept
 The need for High degree of Multiplexing of power, readout etc.
Lead to the concept of treating a set of modules in common.
 The mechanical support can be ATLAS like support (Drums) or
mechanical Stave.
 For each group of modules:
 power, readout, grounding “fully contained”
 Service design needs to be “integrated” to the mechanical
and layout.
 Some of these issues are independent if it is a real or
“virtual” stave.
At this stage we try to propose a level of multiplexing that will allow to
get an estimate for services volume and routing.
The decision on the mechanical concept will have to be discussed
with the engineering team that will design the mechanical structure.
SS Multiplexing
A possible multiplexing granularity is as follows:
1) The individual sensor module size is made of a 35x40.96 mm
2) A group of four individual modules are joined together to
make a “super module”
3) A group of ~ 10 super modules are grouped together as a
“stave” for multiplexing purpose.
Each of the groups have self contained services: Cooling, Readout,
power etc.
LS Multiplexing
Concept is very similar to the SS multiplexing. The difference is
mostly in the dimensions of the individual sensors.
Open System Questions.
 Cooling:

Cooling System


Heat Shield


Identical for all layers
One cooling region?
Operating temperature

Identical for all layers
 Support Structure

Al vs. composite material
 Power Distribution:

Multiplexing schemes



In the coming month we
should collect the list of
questions and possible
solutions for the
Engineering questions.
DC-DC
Serial Power
Redundancy
Solutions will have to wait
for detail engineering
studies.
Conclusions
How do we proceed?