1. Material and thickness for pi0 Y.Sudo Univ. of Tsukuba 2008/07/18

2. I calculated probability that two gammas from pi0 are detected in SciEcal. I used Iron and Aluminum for target to make pi0. Parameters Beam : pi+ Energy : 25, 36GeV (5,10,16,25,36,50GeV for Iron 64mm) Target material and thickness Iron 32, 64, 96mm Aluminum 150, 200mm (250mm now running)

3. Result1 Iron 64mm Energy Pi+ : N pi+ : N pi0 : probability(x10 -4 ) 5 : 51500 : 6 : 1.16 +- 0.48 10: 41500 : 6 : 1.44 +- 0.59 16: 31500 : 19 : 6.03 +- 1.39 25: 23221 : 28 : 12.06 +- 2.28 36: 15831 : 18 : 11.37 +- 2.68 50 : 10595 : 13 : 12.27 +- 3.41 N pi0 N pi+

4. Result2 Iron 32mm Energy Pi+ : N pi+ : N pi0 : probability(x10 -4 ) 25: 11000 : 3 : 2.73 +- 1.58 36: 7500 : 7 : 9.33 +- 3.53 N pi0N pi+

5. Result3 Iron 96mm Energy Pi+ : N pi+ : N pi0 : probability(x10 -4 ) 25: 11000 : 9 : 8.18 +- 2.73 36: 7500 : 10 : 13.33 +- 4.22 N pi0 N pi+

6. Result4 Aluminum 150mm Energy Pi+ : N pi+ : N pi0 : probability(x10 -4 ) 25: 11000 : 17 : 15.45 +- 3.75 36: 7500 : 14 : 18.67 +- 4.99 N pi0 N pi+

7. Result5 Aluminum 200mm Energy Pi+ : N pi+ : N pi0 : probability(x10 -4 ) 25: 11000 : 19 : 17.27 +- 3.97 36: 7500 : 14 : 18.67 +- 4.99 N pi0 N pi+

8. Summary pi+ 25GeV Material : thickness : probability(x10 -4 ) Iron : 32mm : 2.73 +- 1.58 : 64mm : 12.06 +- 2.28 : 96mm : 8.18 +- 2.73 Aluminum : 150mm : 15.45 +- 3.75 : 200mm : 17.27 +- 3.96 pi+ 36GeV Material : thickness : probability(x10 -4 ) Iron : 32mm : 9.33+- 3.53 : 64mm : 11.37 +- 2.68 : 96mm : 13.33 +- 4.22 Aluminum : 150mm : 18.67 +- 4.99 : 200mm : 18.67 +- 4.99 Al is better than Fe for material of the target to detect two gammas from pi0. 200mm thick Al is a little bit better than 150mm.