1. HCAL Modules -First Ideas
Mechanical Constraints
HCAL Base Unit (HBU)
Light Calibration System
Further development of the HCAL-Group‘s ideas.
Mathias Reinecke
HCAL – CALICE meeting

2. Mechanical Constraints
HCAL Half-Sector with 38 layers
Height: ~2.6 cm per layer
Width B increases with
1.02 cm per layer
Tile Size 3 x 3 cm²
=> Tiles (Half Sector)
Smallest layer: 74 x 220 cm²
Largest layer : 96 x 220 cm²
Combine many
HBUs to layer-
units for assembly.
Layer Concentrator (Signals / Power)
HCAL Base-Unit (HBU):
- each HBU is 12 tiles (36 cm) deep
- always 6 HBUs in a row cover the full sector length
- 2 or 3 HBU-rows of different widths cover a layer
Mathias Reinecke
HCAL – CALICE meeting

3. Mechanical Constraints
Requirements for a HCAL Base-Unit (HBU)
from the Barrel‘s mechanics:
As large as possible (assembly time)
As thin as possible (barrel diameter)
Easy de-/installation of single units
(repair)
-If possible: not larger than 43cm
(PCB assembly, unit construction, stability)
-Rail System needed (Sector walls ?)
-Minimize dead area
Number of SiPM inputs per ASIC ???
HCAL: 2 x 8 Sectors
2,432,000 Tiles
Mathias Reinecke
HCAL – CALICE meeting

4. How to Fill the Sector‘s Layers
Depths of all HBUs: 12 tiles (36 cm), 6 HBUs = 216cm
Sector layer widths: 24 tiles (72cm) to 33 tiles (99cm)
Layer Width
[tiles]
HBU width [tiles]
Tiles per HBU
Unused HBU inputs for ASIC with
54 inputs
72 inputs
64 inputs 24
12+12
8+8+8
144 96 18 12 - 48 32 25
12+13
8+8+9
156
108 6 60 36 20 27
120 42 8 28
8+9+11 72
132 30 56 33
Needed HBU widths :
54‘er ASIC: 8, 9, 11, 12 and 13 tiles width or
72‘er ASIC: 6, 8, 10, 11 and 12 tiles width.
Switch off
unused inputs !!
Mathias Reinecke
HCAL – CALICE meeting

5. Tiles in the HBU Standard Tile: 30 x 30 x 3 mm³ Mechanics Tile:
HBU interconnection
and HBU module setup
Minimum:
8 of 144 tiles
in a HBU
6mm bolt with
M3 thread inside
Tile Alignment Pins
~ 2mm height
SiPM Carrier
Mathias Reinecke
HCAL – CALICE meeting

6. HBU – How could it look like ?
Reflector Foil
100µm
Polyimide Foil
100µm
HBU Interface
500µm gap
ASIC
LQFP-144
1.4mm high
PCB
1mm
Sector
wall
Top Plate
600µm steel
Spacer
1.7mm
Top Plate
fixing
Component Area:
1.7 mm high
HBU height:
7.2mm
(6.0mm without covers => absorber)
SiPM
Bolt with inner
M3 thread
welded to bottom
plate
Bottom Plate
600µm
Tile
3mm
Absorber
Plates
(steel)
Mathias Reinecke
HCAL – CALICE meeting

7. HBU height – Component Area
There is still room for improvement !
-HBU Interconnection (1.3mm):
Connector alternative: 1.5mm stacking height
SiPM Solder Pins (1.5mm):
1mm possible?
ASIC (1.4mm):
1mm: max 100 pins
-Blocking Capacitor (1.1mm):
0.8mm: max 4.7µF
Mathias Reinecke
HCAL – CALICE meeting

8. HBU Insertion (Top View)
HBU Interconnection:
Close Mechanical Tabs
Close Electrical Conn.
Push into Sector Layer
Repeat 1-3:
Two layer units in
a sector layer.
Top plate
fixing
(next to
sector wall)
Tile
Spacer (various shapes possible)
PCB
Steel
Absorber
ASIC
Mathias Reinecke
HCAL – CALICE meeting

9. Light Calibration System
Use ‚Distance‘ of Single-Photon Peaks for calibration
(LED light output level not critical),
couple LED light into the Tile Alignment Pins:
LED
PCB
Reflector
Foil
One LED per tile : No fibers needed.
One LED per HBU : No fibers between modules (HBUs)
Mathias Reinecke
HCAL – CALICE meeting

10. Conclusions Very first idea about how things could look like.
Nothing of the shown topics is fixed.
First test setups are needed to answer basic questions:
- performance, noise and crosstalk
in such a compact module
- connector stability
- mechanical optimization (height)
Mathias Reinecke
HCAL – CALICE meeting