SLHC Local Support Requirements Summary M. Gilchriese November 4, 2008

Radiation Levels This is what I assume(6000 fb -1 )….needs update(Dawson) 2 Will be able to validate with data well before designs frozen…

Heating Front-end electronics + local cables(Fabian, Maurice) – Nominal: 0.3 W/cm 2 – Maximum: 0.5 W/cm 2 Environmental heating - TBD Needs real calculations and comparison to data from current detector. Non-uniform (convection)….. Sensor heating – See plots on next pages for 3D and n-in-p – Also must estimate leakage current vs temperature. I take 100 nA per pixel as the maximum, which implies a temperature limit for fixed fluence 3

3 D Sensor Heating – Input Data Large spread in data – take worst for now 4

3D Sensor Heating Extrapolated to -25C for comparison. Should be about linear…. Highest fluence? 5 FluenceW/cm 2 -25C 7.50E E E E E E E

n-in-p Sensor Heating Source: A. Affolder presentation 6

Leakage Current n-in-p for 900V 50x250  2 pixel Plot is temperature at which pixel leakage current is 100nA vs power at -25C 3D – remember data spread! Assume 125V Need cold! 7 Achievable with C 3 F 8 ? Max?

Mechanical Detailed specifications to be developed but should be guided by alignment experience with current detector. Short term stability ie. within time window for alignment with tracks  micron level. This will not change. Vibrational spec. TBD. Thermal and moisture distortions – Current detector(barrel) has large distortions. Will it matter? Need experience! This will take year(s)…OK – In the meantime, design to minimum CTE and CME effects. 8

Module Interface Again need alignment experience from current detector. Track-based alignment will be very well developed tool 10 years from now Local support design must allow for…. Placement accuracy  50 microns Local survey accuracy – it’s hard not to do <10 microns on local supports but may not be needed. Interface to global support survey – make it easier. New techniques beyond traditional touch or optical survey in next years? 9

Reliability Critical!!!! Detailed requirements for reliability need to be developed. But given our experience… – Radiation up to 10 7 Gy – Number of thermal cycles  many hundreds ? – Corrosion or similar effects – Cooling interface – no leaks Design qualification for reliability will be a challenge! Needs much more effort but hard…. 10 Sources for fast radiation to this level? Not easy to do 1000 thermal cycles