Powering via Cooling Pipes: an Optimized Design for an SLHC Silicon Tracker

TL;DR

This paper presents an optimized cooling system using long aluminum pipes with CO2 for SLHC silicon trackers, reducing material and thermal stresses while maintaining effective cooling at -30°C.

Contribution

It introduces a novel large-scale, low-material cooling pipe system with long service connections, enhancing tracker design for high radiation environments.

Findings

Feasibility demonstrated through initial tests.

Significant reduction in material budget.

Effective cooling with negligible thermal stresses.

Abstract

Silicon trackers at the SLHC will suffer high radiation damage from particles produced during the collisions, which leads to high leakage currents. Reducing these currents in the sensors requires efficient cooling to -30 C. The large heat of evaporation of CO2 and the low viscosity allows for a two-phase cooling system with thin and long cooling pipes, because the small flow of liquid needed leads to negligible temperature drops. In order to reduce the material budget a system is proposed in which a large scale tracker requiring ca. 50 kW of power is powered via 1-2 mm diameter aluminum cooling pipes with a length of several m. These long cooling pipes allow to have all service connections outside the tracking volume, thus reducing the material budget significantly. The whole system is designed to have negligible thermal stresses. A CO2 blow system has been designed and first tests show the feasibility of a barrel detector with long ladders and disks at small radii leading to an optimized design with respect to material budget and simplicity in construction.