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Simulation for Commissioning Runs

In this section, the cross section, rate, required total number of events, and the estimated beam time for reference cell runs during commissioning are presented. The beam energy is 1.198 GeV. At an angle of 20$^\circ$ the (reference) cell windows will be within acceptance and its contribution is estimated using: $\sigma_{\rm {GE180}}=\sigma_{^3He}\times\frac{2\times d_{\rm {GE180}}}{25\rm {cm}}\times\frac{\rho_{\rm {GE180}}}{\rho{^3He}}(\frac{Z_{\rm {GE180}}}{Z_{^3He}})^2$. Elastic scattering from window has a cross section of $32.6\times\sigma{^3He}$ at 10atm, which gives a rate of 22.1 kHz with beam current 15$\mu A$. For quasi-elastic window gives $12.6\times\sigma{^3He}$ at 10atm. During commissioning prescale factors should be set properly such that the high rate from window will not kill DAQ. In on-line analysis windows need to be cut off (in $y_{tgt}$) to make sure if enough data has been collected.


next up previous contents
Next: About this document ... Up: E99117_runplan Previous: Estimation of electron, pion   Contents
Xiaochao Zheng 2001-06-09