1. Data from MAS GCALOR with phojet min-bias events in ATLAS detector
Calorimeter
Data from MAS GCALOR with phojet min-bias events in ATLAS detector
5-April-2009

2. 3D 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
Copper Matrix
Copper Matrix
0.05 mm gap here

3. Al Tube Eccentricity
Argon
Copper matrix

4. 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.

5. Conductivities Y Z X

6. Heat Generation Rate, W/mm^3

7. Heat Generation Rate, W/mm^3

8. Steady State Temperatures, All Components

9. Steady State Temperatures, Argon Excluded

10. Steady State Temperatures, Argon Excluded
This view demonstrates that the OD is held to 90°K

11. 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

12. Mesh Refinement Checks (2D Models)
Baseline
Twice Refined
Once Refined

13. Mesh Refinement Checks, Heat Generation
A simplified spatial distribution of heat generation is used for these models. Units are W/mm3

14. Mesh Refinement Checks
Baseline
Tmax = K
Once Refined
Tmax = K
Twice Refined
Tmax = K
There is little change in the 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

15. Comparison of 2D and 3D Results
Using the specified distribution of heat generation in both models:
The 3D model result is:
Max argon temperature °K
Max metal temperature °K
The 2 D model result is:
With a uniform 1.95 mm gap at the OD
Max argon temperature °K
Max metal temperature °K
With a uniform 1 mm gap at the OD
Max argon temperature °K
Max metal temperature °K
These results suggest that in the 3D model heat is being conducted to the bottom of the collimator where the argon gap is small.