LDC strip angle optimization

SiLC Genf, Sept. 10, 2007 M. Regler, M. Valentan, W. Mitaroff

Optimization of the strip angles of the LDC endcaps

using the LiC Detector Toy

LDC strip angle optimization

SiLC Genf, Sept. 10, 2007 M. 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)

LDC strip angle optimization

SiLC Genf, Sept. 10, 2007 M. Regler, M. Valentan, W. Mitaroff

The Detector Setup

LDC strip angle optimization

SiLC Genf, Sept. 10, 2007 M. Regler, M. Valentan, W. Mitaroff

Standardized MC-Residuals

LDC strip angle optimization

SiLC Genf, Sept. 10, 2007 M. Regler, M. Valentan, W. Mitaroff

Output: Residuals

LDC strip angle optimization

SiLC Genf, Sept. 10, 2007 M. Regler, M. Valentan, W. Mitaroff

Output: Impacts

LDC strip angle optimization

SiLC Genf, Sept. 10, 2007 M. Regler, M. Valentan, W. Mitaroff

Results (7.5° < θ < 8°, pt = 5-6GeV; 25-26GeV)

Strip distance d=90μm

Optimal case, see alsonext transparency

+: Additional endcap

LDC strip angle optimization

SiLC Genf, Sept. 10, 2007 M. Regler, M. Valentan, W. Mitaroff

Strip distanced=90μm

Results (8.5° < θ < 9°, pt = 5-6GeV; 25-26GeV)

: Radius FTD7 increased

+: Add. endcap

: Both

: Both with inefficiency

X: Original with ineff.

LDC strip angle optimization

SiLC Genf, Sept. 10, 2007 M. 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