1. LDC strip angle optimization SiLC Genf, Sept. 10, 2007M. Regler, M. Valentan, W. Mitaroff Optimization of the strip angles of the LDC endcaps using the LiC Detector Toy

2. LDC strip angle optimization SiLC Genf, Sept. 10, 2007M. Regler, M. Valentan, W. Mitaroff The LiC Detector Toy Software Simple, but flexible and powerful tool, written in MatLab Detector design studies –Geometry, material budget –Resolution, Inefficiencies Simulation –Solenoid magnetic field, helix track model –Multiple scattering, measurement errors and inefficiencies –Cylinders (barrel) or planes (forward/rear) –Strips and pads, uniform and gaussian errors (in TPC with diffusion corr.) Reconstruction –Kalman filter –Fitted parameters and corresponding covariances at the beamtube Output –Resolution of the reconstructed track parameters inside the beam tube –Impact parameters (projected and in space)

3. LDC strip angle optimization SiLC Genf, Sept. 10, 2007M. Regler, M. Valentan, W. Mitaroff The Detector Setup

4. LDC strip angle optimization SiLC Genf, Sept. 10, 2007M. Regler, M. Valentan, W. Mitaroff Standardized MC-Residuals

5. LDC strip angle optimization SiLC Genf, Sept. 10, 2007M. Regler, M. Valentan, W. Mitaroff Output: Residuals

6. LDC strip angle optimization SiLC Genf, Sept. 10, 2007M. Regler, M. Valentan, W. Mitaroff Output: Impacts

7. LDC strip angle optimization SiLC Genf, Sept. 10, 2007M. Regler, M. Valentan, W. Mitaroff Results (7.5° < θ < 8°, p t = 5-6GeV; 25-26GeV) Strip distance d=90μm Optimal case, see also next transparency +: Additional endcap

8. LDC strip angle optimization SiLC Genf, Sept. 10, 2007M. Regler, M. Valentan, W. Mitaroff Strip distance d=90μm Results (8.5° < θ < 9°, p t = 5-6GeV; 25-26GeV) : Radius FTD7 increased +: Add. endcap : Both : Both with inefficiency X: Original with ineff.

9. LDC strip angle optimization SiLC Genf, Sept. 10, 2007M. Regler, M. Valentan, W. Mitaroff Conclusions Strip angle of 90° seems to be the best solution The gap between the forward detectors and the TPC has to be reduced to a minimum –If necessary, the z position of the outermost detector has to be changed Inefficiencies: –Resolutions stable with additional endcap –Without additional endcap seems to be stable, too, but a track loss of 10% occurs Best solution: –Extend the outer radius of FTD7 as much as possible to fill the gap –Add an additional endcap FTD8