R&D Status of FPCCD Vertex Detector Dec.1, 2006 Yasuhiro Sugimoto KEK

Introduction FPCCD Vertex Detector Accumulate hit signals for one train and read out between trains  Completely free from EMI Fine pixel of ~5  m (x20 more pixels than “standard” pixels) to keep low pixel occupancy Fully depleted epitaxial layer to minimize the number of hit pixels due to charge spread by diffusion Two layers in proximity make a doublet (super layer) to minimize the wrong-tracking probability due to multiple scattering Tracking capability with single layer using cluster shape can help background rejection Three doublets (6 CCD layers) make the detector Multi-port readout with moderate (~20MHz) speed Operation at low temperature to keep dark current negligible (r.o. cycle=200ms)

Baseline design for GLD

Challenge of FPCCD Fully depleted Lorentz angle tan  =r H  B, r H : Hall coefficient~1,  : mobility (m 2 /Vs), B: Magnetic field (T) Stronger E-field in dep. layer (>10 4 V/cm = 1V/  m) gives saturation of carrier velocity and smaller   Epi layer of ~15  m would be OK Radiation tolerance Small pixel （ ~5  m) Fast readout speed （ ~20 Mpix/s ） Multi-port readout H-Register in image area Low noise: <50 e (total)  < 30 e (CCD) Low power consumption Metal layer Low drive pulse voltage Output circuit Large area:10x65mm 2 （ in ） /20x100mm 2 （ out ） Thinning （ <50  m) Full well capacity >10 4 e is OK Readout ASIC Necessary for proto-type ladder

Roadmap DCRDODLOI Construction Study of fully Depleted CCD Design of small Prototype of FPCCD FPCCD fabrication Sample test 2nd round3rd round (prototype ladder) Development of readout ASIC for prototype CCD Wafer thinning and the support structure Other 2nd priority R&Ds ILC Project (Detector) DOD: Detector Outline Document DCR: Detector Concept Report LOI: Letter of Intent (?) FPCCD VTX

Short term plan Study of fully depleted CCD New CCDs will be delivered mid December Epi-layer: 30  m / 15  m Pixel size: 24  m Study of charge spread and Lorentz angle Radiation tolerance Study of support structure FEA study of Si-Carbon foam-Si structure

Charge spread Front illumination Standard Back illumination Deep2