Tests and measurements with a thermal VXD mock-up for BELLE II

As part of the Belle detector upgrade, located at the KEK in Tsukuba, Japan, a CO2 cooling system willbe added. Using new detector components, which are easily damageable or influenced by heat, makethis step necessary. Particularly the next to the beam pipe located PXD is strained by high thermal loadand therefore requires cooling. The CDC needs a constant temperature for precise measurements, butit could be influenced by heat from the SVD. Knowledge about the heat generation and distribution isneeded before assembling the full detector. A mock-up of the innermost parts of the detector and aCO2 cooling system is under construction at DESY in Hamburg, Germany, to gather such knowledge.The mock-up should be able to emulate the thermal properties of the final detector. Within the scopeof this bachelor’s thesis, the outermost VXD Layer 6 was studied in a flat arrangement. Focus layon the heat dissipation at the sensors and on pressure drop measurements of the cooling pipe. It wasinvestigated whether the applied heat load can be suciently lead away and how large the pressuredrop is along the experiment line. Despite cooling was applied, a remarkable rise in temperature wasobserved. However, the unfavorable position of the thermistors make reliable quantitative statementsof the sensor dummies’ temperatures impossible. The pressure drop was determined, but is of limitedaccuracy due to large uncertainties. Further investigations have to be made with a better set-up