1. Fluka Simulations: Electron spectrometer window for AWAKE Jose A. Briz and V. Vlachoudis

2. Beam and target properties Beam properties Particles: electrons Two types of beams: 1.-Unaccelerated beams: 1.25x10 9 particles per bunch at ~16 MeV 2.-Accelerated beams: 30% x 1.25x10 9 particles per bunch at ~1.3 GeV Window properties 1-m-wide x 6.5-cm-high window Different configurations to test: -2 mm thick Aluminum 5083 H111 or Aluminum 6082T6 -1 mm thick Stainless Steel 304L -1 mm thick Ti 6 Al 4 V

3. Beam impact location WINDOW WINDOW size: 1 m wide (-50,+50) 6.5 cm high (-3.25,+3.25) Window properties 3 configurations to test: -2 mm thick Aluminum 5083 H111 or Aluminum 6082T6 -1 mm thick Stainless Steel 304L -1 mm thick Ti 6 Al 4 V

4. Results on energy deposited

5. Unaccelerated beam for Al5083 Maximum energy density: 60 mJ/cm 3 /bunch

6. Accelerated beam for Al5083 Maximum energy density: 0.4 mJ/cm 3 /bunch

7. Unaccelerated beam for Titanium Maximum energy density: 95 mJ/cm 3 /bunch

8. Accelerated beam for Titanium Maximum energy density: 0.65 mJ/cm 3 /bunch

9. Unaccelerated beam for SS Maximum energy density: 180 mJ/cm 3 /bunch

10. Accelerated beam for SS Maximum energy density: 0.65 mJ/cm 3 /bunch

11. Maximum energy densities - Comparative Most critical beam: Unaccelerated Unacc: 60-180 mJ/cm 3 /bunch Accel.: 0.4-1.2 mJ/cm 3 /bunch Highest energy deposited in Stainless Steel AcceleratedUnaccelerated SS Al6082T6 Ti Al5083

12. Temperature increases Material Max. Edep (mJ/cm 3 ) Max. ΔT (ºC) Melting point ( ºC ) Aluminum 5083 or 6082T6 60.00.024555 Stainless Steel 180.00.051400 Ti 6 Al 4 V100.00.041600 Unaccelerated beam Almost negligible temperature increase per pulse

13. Integrated energy deposition MaterialBeam type Average Incident Energy (MeV) Average deposited energy per primary (MeV) Aluminum 5083 or 6082T6 Unaccel.16.01.13 Accel.1330.0.90 Stainless Steel Unaccel.16.01.72 Accel.1330.1.30 Ti 6 Al 4 V Unaccel.16.0.88 Accel.1330.0.71

14. Conclusions Almost negligible temperature increases per pulse ( ΔT≤0.05 ºC) Highest energy deposition in Stainless Steel Average energy deposition per primary ~1 MeV (0.7-1.7 MeV)