Speakers
Description
The ATLAS Inner Tracker (ITk) of the phase-II upgrade programme is designed to meet the challenges at the high-luminosity LHC. The ITk silicon strip end-caps will cover the forward directions of the detector and consist of six disks populated with wedge-shaped silicon micro-strip sensors, divided in modules containing the readout, power and control electronics.
The main building blocks are the so-called petals consisting of likewise wedge-shaped local support structure called petal cores with sensor modules in six different shapes directly glued on them.
The core is made of a carbon fiber-based sandwich structure with an embedded titanium cooling pipe for evaporative CO2 cooling and provides data and power buses to connect the modules to the off-detector electronics.
For the thermal QC during production, the petal cores will be evaluated by infrared thermography. The thermal performance results from several prototypes will be discussed together with the influence of the dual-phase CO2 coolant, such as heat load or mass flow rate, on the cooling performance.
Furthermore, the first petal prototype loaded with fully electrical modules is used to validate the petal cooling concept using dual-phase CO2. At different set points of the cooling system, electrical tests are performed on the modules evaluating the corresponding noise behavior. Also, the thermal load from the different readout ASICs and the module powering is systematically studied by infrared thermography and measuring the module temperatures by NTC sensors. The experimental results are finally compared to thermal FEA studies of the petal.
