Calorimeter Data from MAS GCALOR with phojet minbias
Calorimeter Data from MAS GCALOR with phojet min-bias events in ATLAS detector 5 -April-2009 1
3 D Model of Calorimeter Al tube is modeled with shell elements. Its temperature is set to 90°K. It is eccentric. Argon 1. 95 mm gap on top Tungsten Matrix Copper Matrix 0. 05 mm gap here 2
Al Tube Eccentricity Argon Copper matrix 3
Aluminum Shell and Argon Elements The aluminum shell, above, is wrapped around the OD. It is currently being used as a convenient surface to fix at 90°K. Plate elements are used. They are being plotted here as a surface (no thickness). Liquid argon is modeled with solid conduction elements as shown above. The aluminum shell plates the outer surface. 4
Conductivities Y Z X 5
Heat Generation Rate, W/mm^3 6
Heat Generation Rate, W/mm^3 7
Steady State Temperatures, All Components 8
Steady State Temperatures, Argon Excluded 9
Steady State Temperatures, Argon Excluded This view demonstrates that the OD is held to 90°K 10
Steady State Temperatures, Argon Jacket Gradient 0. 079° K through the 1. 95 mm thick argon jacket here 0. 012° K through the 0. 05 mm thick argon jacket here 11
Mesh Refinement Checks (2 D Models) Baseline Once Refined Twice Refined 12
Mesh Refinement Checks, Heat Generation A simplified spatial distribution of heat generation is used for these models. Units are W/mm 3 13
Mesh Refinement Checks Baseline Once Refined Twice Refined Tmax = 90. 186 K Tmax = 90. 185 K Tmax = 90. 184 K There is little change in thermal solution as the mesh is refined. The discretization error is approximately 1. 1% These results use a uniform OD gap of 1. 95 mm 14
Comparison of 2 D and 3 D Results • Using the specified distribution of heat generation in both models: – The 3 D model result is: • Max argon temperature • Max metal temperature 90. 147°K 90. 109°K – The 2 D model result is: • With a uniform 1. 95 mm gap at the OD – Max argon temperature – Max metal temperature 90. 188°K 90. 212°K • With a uniform 1 mm gap at the OD – Max argon temperature – Max metal temperature 90. 129°K 90. 138°K • These results suggest that in the 3 D model heat is being conducted to the bottom of the collimator where the argon gap is small. 15
- Slides: 15