1. Studies for a silicon detector in a e/A collider Benedetto Di Ruzza BNL EIC Task Force meeting August 28 th 2014

2. Momentum resolution studies for a silicon detector in a eRHIC collider using the EICRoot framework. Some consideration on bremsstrahlung for electron in silicon. The ITS Alice upgrade. outline 2

3. Momentum resolution studies performed using a simple detector model in the EICRoot framework Momentum resolution studies 3

4. Detector model: barrel Momentum resolution studies Electron energies: 5, 15 and 20 GeV Eta : 0, 0.5, 1,1.5, 2, 2.5, 3 Forward and Rear: 4

5. In each configuration performed the simulation of 2000 events. Momentum resolution studies 5

6. Crystal ball function “like” used in the fit fit: Momentum resolution studies 6

7. Crystal ball function like function used in the fit: Momentum resolution studies 7 P0= alpha, P1= n; P2= mean, P3= sigma, P4=N

8. Ratio tail/all events Momentum resolution studies 8

9. Repeat the fit with a crystal ball function change particles and detector design Still to do: 9

10. electron bremsstrahlung in Si Plot Energy loss in lead Critical energy From PDG 2013 Si Z=14 10

11. electron bremsstrahlung in Si 11

12. electron bremsstrahlung in Si 12 Some calculation with X 0 =9.36 cm Fraction of energy loss by electrons for bremsstrahlung For 300 µm silicon: exp -(0.03/9.36)=0.0032 Other calculation: using the Bremsstrahlung energy spectrum

13. electron bremsstrahlung in Si 13 Some calculation with X 0 =9.36 cm (thanks to Sasha Bazilevsky for useful discussions) Fraction of energy loss by electrons for bremsstrahlung: Numerical calculation using bremsstrahlung gamma spectrum from PDG: Ratio of Integral over all spectrum/incoming energy = 0.0032 Number of gamma Energy (Gev)

14. The Alice ITS upgrade 14

15. The Alice ITS upgrade 15

16. The Alice ITS upgrade 16

17. The Alice ITS upgrade (inner barrels) 17

18. The Alice ITS upgrade (outer barrels) 18

19. New model implemented in the simulation by Alexander 19

20. New model implemented in the simulation by Alexander 20

21. New model implemented in the simulation by Alexander 21

22. The ITS upgrade cooling system 22

23. The ITS upgrade cooling system 23

24. ratio Momentum resolution studies 24

25. ratio Momentum resolution studies 25

26. ratio Momentum resolution studies 26