REFLECS project

Marco Bomben – LPNHE, Paris

1M. Bomben - REFLECS project kickoff meeting - 02/04/2014

Outline

• Reflecs project: goals, constraints & manpower, scope

• What can be done within REFLECS?


REFLECS: THE PROJECT


Project goals

• Develop a µ-channel based cooling system exploiting the possibilities offered by 2-phase CO2

– REFroidissement Léger au CO2 en Silicium

• Aim: Atlas Phase-II; data taking: from 2024 onwards


Project constraints

Time: all budget must be used by the end of 2014Money: we have been assigned 16 k€Expenses:

1. we cannot hire people2. we can buy material, having work done elsewhere3. we can pay a stagiaire4. we can pay travel expenses


Project: groups, people involved

LPNHE: Giovanni Calderini (senior researcher), M.B. (Post-doc) Filipe de Matos (research engineer)

IEF: Jean-Rene Coudevylle (research engineer), Frédéric Hamouda (research engineer)

CMM: Maurizio Boscardin (senior researcher) MPI: Anna Macchiolo (senior post-doc)


Project scope

1. A demonstrator consisting of a pixel detector module cooled via µ-channels and CO2

– Probably not enough budget to accomplish this…

2. Work on connections between different modules

Silicon substrate – 300 - 700 µmSilicon substrate – 300 - 700 µm

R.O. chip – 100-150 µmR.O. chip – 100-150 µm

Sensor – 200 µmSensor – 200 µm


Upgrade tracker pixel stave

• How to deliver efficiently the coolant?Find suitable in plane connections

z

φ

R

carbon frame suppor

t

module w/

cooling channel

s

Scheme: courtesy of J.W.

parallel coolant

distribution


I-beam stave concept


40 – 100 cm

40 – 100 cm


Pixel module

Pixel module



Outer coolant route

Inner coolant route


Cooling requirements needs for new pixels

• To avoid negative annealing future sensors must be operated well below 0 °C ideally: -20 °C

• Sensor+chip will dissipate ~ W/cm2

• Important constraint: very low material budget envisaged ( < 1% X0)

A very efficient cooling system is needed


WHAT CAN BE DONE WITHIN REFLECS?


What can be done: cooling plates

• Realize some (how many?) cooling plates for FEI4 sensors-chip assemblies (size: 20 x 20 mm2)

In our case:~ 10 – 15 parallel channels3x side length ~ 60 mm longChannels: 70-100 µm deep

500-1000 µm

Pyrex closure? Or Silicon?Possibility to etch 6” wafers? 8”?Buried channels?Etch channels on sensors? (unlikely)But still: can we etch the support wafer of our edgeless production?

LHCb - CNM

FBK-CMM


Some examples from literature

What can be done: cooling distribution system?

• Long staves (400-1000 mm) requires a coolant distribution system “parallel” to the stave

• Microfluidic tapes?

– Below the stave?– If yes: how can we create holes in the cooling plate?


Backup material


A STUDY CASE: UPGRADE OF THE ATLAS PIXEL DETECTOR


LHC in a nutshell


Atlas


Current Atlas pixel detector


Upgrade Inner Detector Layout (LoI – DRAFT)

Forward extensionForward

extension

More disksMore disks

More pixel

layers

More pixel

layers

More strip layers

More strip layers


Upgrade LoI pixel barrel

X

Beam



First layer



Second layer


Phase-II LoI pixel barrel

I-beam stave


Documents

REFLECS project