Speaker
Description
The Compressed Baryonic Matter Experiment (CBM) at the Facility for Antiproton and Ion
Research (FAIR) is a fixed-target spectrometer designed to explore the high-density regime of the
QCD phase diagram at √sN N = 2.9 - 4.9 GeV (Au-Au collisions) with interaction rates reaching
10 MHz. The Inner Tracker is compromised of the Micro Vertex Detector (MVD) and the Silicon
Tracking System (STS) housed inside a superconducting dipole magnet.
The first part of this contribution pertains to the CBM-MVD which uses CMOS MAPS for
its four detection planes, offering high spatial (∼ 5 μm) and time (∼ 5 μs) resolution, with good
radiation tolerance (∼ 5 MRad, ∼ 7 × 1013 neq/cm2). The MVD sensors will operate in vac-
uum at ≈ 0◦C by mechanically supporting them on Thermal Pyrolytic Graphite carriers (TPG,
∼ 1500 W/m·K), conducting the heat to actively cooled heat sinks (3MTM NOVECTM 649) out-
side the physics aperture to ensure a material budget of 0.3% − 0.5% X0 per plane. There will be
special focus on the preparation of TPG carriers which feature pros (thermal conductivity, price)
and cons (surface quality, softness). Solutions developed during prototyping will be presented,
recommending employing TPG in high-precision vertex trackers.
The second part of this contribution pertains to the CBM-STS which uses double-sided silicon
micro-strip sensors for its eight detection planes, offering high track reconstruction efficiency (>
95%) and momentum resolution (< 2%). The silicon sensors are mechanically held by light-weight
carbon fibre ladders, while the electronics along with its cooling are placed outside the physics
aperture to provide a material budget of 0.3% − 2% X0 per plane. The STS sensors will operate at
≈ 10◦C to mitigate the radiation damage of 1 × 1014 neq/cm2. There will be special focus on the
thermal management strategy of using liquid-assisted air cooling. This approach involves cooling
silicon sensors with impinging cold air jets to remove the sensor power dissipation (∼ 54 mW/cm2),
while the 40 kW power dissipation from electronics is cooled with liquid 3MTM NOVECTM 649.
Detailed experimental investigation will be presented verifying the cooling concept with a realistic
STS thermal demonstrator.
| Collaboration | CBM |
|---|---|
| Role of Submitter | I am the presenter |
