1. JC and Marina 12/18/00 Pixel Detector Simulation with Magnetic Field  Effects with magnetic Field o Deflection o Effective mobility o Non-constant Hall mobility  Comparison with magnet run

2. Jianchun (JC) WangSyracuse University2 Magnetic Field

3. Jianchun (JC) WangSyracuse University3 Deflection in Magnetic Field n+n+ n p+p+ -V 0 V  e e e e e e e e e e e e e B y  Effect of magnetic field  Effect of incident angle

4. Jianchun (JC) WangSyracuse University4 Deflection in Magnetic Field Assumption:  H = constant  eff =  The charge distributions are the same with B or 

5. Jianchun (JC) WangSyracuse University5 Effective Mobility Very small effect: B field  Cloud drifts slower  Larger Spread

6. Jianchun (JC) WangSyracuse University6 E-dependent Mobility Larger E  Smaller  Hall   Smaller deflection P + side larger E N+ Side Smaller E

7. Jianchun (JC) WangSyracuse University7 Effect of Magnetic Field With non-constant  Hall (E), and  eff The charge distributions are slightly different

8. Jianchun (JC) WangSyracuse University8 Conclusion We Don’t expect the magnetic field will reduce the ratio between two-pixel clusters and one-pixel clusters

9. Jianchun (JC) WangSyracuse University9 Magnet Run  Track at 1.3  angle ( ~ 0.242 Tesla )  Measurement: R min = 0.193  Simulation ( Q th = 2.5Ke ): R min = 0.250 What is wrong ?

10. Jianchun (JC) WangSyracuse University10 Magnet Run  Track at 1.32  ( 23 mrad ) ( ~ 0.245 Tesla )  Measurement: R min = 0.193  Simulation ( Q th = 4.0Ke ): R min = 0.197 Just to Play around But there is no other evidence that threshold was wrong

11. Jianchun (JC) WangSyracuse University11 Magnetic Field Measured with Gauss meter: 45A  0.585 Tesla Assume overall scale of the magnetic field uncertain Use MC simulation to fit  0.517 Tesla (error?) Error of Hall factor (  Hall /  =1.15) can make up the difference

12. Jianchun (JC) WangSyracuse University12 Summary  MC simulation accurate both for drift and B field simulation  Magnet Run data is not fully understood yet