1. Tas and Q0: Simple parametric study for Tas 15/03/07
Elena Wildner

2. Strategy 15/03/07 Wish from ATLAS: complete proposal from machine side
The shielding is designed including the TAS
Optics case fixed (see layout sketch)
Simple model of shielding structure has been made, with new layout
For D0: large aperture (not same angles?), for Q0 and Tas studies only dipole field to be included

3. Layout sketch of possible scenario
Detector for backscattering: shielding IP
Tas
Q01
Q02
9 m
3.0 m
13 m
3 m
3.5 m

4. Moving Tas in the Atlas model
Shielding needed around Tas, if Tas moved shielding has to be redesigned IP IP

5. Atlas shielding 8m
13m
21m

6. Atlas shielding

7. Shielding: general

8. Model JN JF JT JD

9. Cross Section of Q0 (G.Kirby)He ss Cu
4.5
10.5
16.5
28.0
30.0
Field Map exists

10. Moving the Tas Using simple cylinder surrounding the Tas
3 positions of Tas calculated, 19 m, 13 m, 9.5 m from IP
2 Tas apertures calculated for 13 m, the second has the same interception angle as the 19 m case.

11. Results, neutrons

12. Results,e+-

13. Results, muons

14. Results, photons

15. The Tas Aperture
Heat deposition and backscattering depends on Tas opening and distance
If the Tas is located closer to IP different particles will be intercepted for the same opening
2 cases for Tas aperture calculated

16. Results, heat deposition on Tas
Deposit in Tas (1900 cm) 181 W (sigma = 29 W),
ref N. Mokhov 187 W
Deposit in Tas (1300 cm) 133 W (sigma = 27 W)
Deposit in Tas ( 950 cm) 108 W (sigma = 27 W)
Deposit in Tas ( 1300 cm) 175 W (sigma = 29 W)
Same angle as the 1900 cm case!!!
Original Tas design
Angle as 1900 cm case

17. Results, “current” out of pipe
Particles per primary
Select particles coming from Tas and check at critical positions
GeV

18. Next: Heat Load on Q0 IP
Tas
Q01
Q02
9 m
3.0 m
13 m
3 m
3.5 m
Optimize ED, by changing Tas and accordingly Q0 parameters (material, geometry) using simple model
Experiment’s possibility to house Tas, discussion
If Q0/Tas ok, experiment optimizes the shielding

19. Status
Status:
Modification of Atlas Shielding at new position of Tas: new model finished ready to be run, magnetic field map from G. Kirby to be integrated. Adding Dipole field from D0.
Parameters: Tas opening, distance, material, shape: Q0 layout kept fix
Is the same approach valid for CMS?