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 13.2.2007

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 => 76000 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 13.2.2007

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 13.2.2007

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 6+10+11 120 42 8 28 6+10+12 8+9+11 72 132 30 56 33 10+12+12 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 13.2.2007

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 13.2.2007

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 13.2.2007

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 13.2.2007

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 13.2.2007

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 13.2.2007

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 13.2.2007