Development of an Open CO2 Cooling System for Belle II

Autoren: Annekathrin Frankenberger
Kategorie: Masters-Thesis

At the KEK (Tsukuba, Japan) a major upgrade of the accelerator system is under

construction and requires a redesign of the entire Belle detector, especially of the

Silicon Vertex Detector (SVD). As a consequence of the new Belle II SVD design, a new

cooling concept for the sensor readout electronics is required. For thermal management

of the Belle II SVD a two-phase evaporative CO2 cooling system is under development.

In order to gain experience concerning the Belle II SVD cooling system, a less

extensive and less complicated cooling plant has been developed. The key issue of

this thesis is the design and construction of an open CO2 cooling system for research,

development and testing. This independent, scalable and transportable cooling plant

is necessary to get familiar with CO2 and to acquire test results which can be applied

to the Belle II SVD cooling system.

One big topic is the component dimensioning and selection with the big challenge of

using o-the-shelf components. Furthermore, a detailed description and explanation of

the design and the assembly is given. After realizing and commissioning, the system

successfully operated in various applications. Despite prevailing rough conditions in a

particle detector, a well functioning but still simple design was worked out.

Other major topics of this thesis are the development of a reliable tube xture mechanism

and the investigation of a material to ensure adequate heat transfer between pipe

and readout electronics. Finally, the developed cooling plant was used to verify the

cooling concept by testing various sensor module prototypes in beam tests.