1. Status report on the Asian Solid State Tracking R&D March 31, 2003 M. Iwasaki University of Tokyo

2. 1.Si  -strip central tracker: Univ. of Tokyo 2.Si  -strip intermediate Tracker: Kyungpook National Univ., Ewha Univ., Yonsei Univ., Korea Univ. Today, I introduce these two groups activities There are two groups working on SI tracker in Asian LC Group

3. 1)Si  -strip central tracker R&D by Tokyo Group Univ. of Tokyo Group: M. Iwasaki, H. Aihara GEANT4 Full simulation study on the SI tracker 1. Basic detector parameter studies 2. Photon BG estimation

4. U. Tokyo Group works on the Full detector simulation of the SI central tracker In Linear Collider environment, Central Tracker must be robust  SI tracker is one of the good candidate for LC In our simulation, we use GEANT4 Full detector simulation + tracker hit position smearing Assuming NLC-SD detector parameters (SDMar01): 5 double-sided Si  -strip layers R = 20cm - 125 cm B = 5.0 Tesla Track finding … cheater (gathering hits from the same particle) Track fitting … Using Kalman Filter (implemented by T.Abe)

5. Silicon Central Tracker

6. Tracker Hit Occupancy 10 -3  10 -2 at inner most e + e -  tt  6 Jets,  s=500 GeV, noISR, no beamstrahlung (strip pitch size * length)

7. - - - #hit  1 in central & #VXD hit=5 - - - #hit  2 in central & #VXD hit=5 - - - #hit  3 in central - - - #hit=5 in central |cos  |<0.8 Vertex Detector linking is important to reconstruct low-P tracks Track Reconstruction Efficiency (Central tracker + VXD)

8. Momentum resolution Generate single particle at |cos  | = 0

9. Photon BG from IR region (from beamstrahlung) We use the  BG data made by T. Maruyama We input this  data  go through GEANT4 detector simulation SDMar01 Tracker region: 180 photons / bunch  180*190 = ~34000  /event Ave. Energy = 1.0 MeV (Peak at 0.511MeV  positron annihilation) Energy distribution for BG photon from IR

10. *On average, ~2000  /event make hits in a SI tracker *Ave. Energy of the photons which make hits in a tracker = 0.7 MeV *Assuming 50  m*20cm strip : one  makes 1.04 hits in average BG photon detector simulation using GEANT4 (input ~34000  /event) (Note: Hits which are seen between layers are from End-cap )

11. Tracker Hit Occupancy Signal: e + e -  tt  6 Jets,  s=500 GeV, noISR, no beamstrahlung Due to the  BG, occupancy increases by an order of magnitude.. But still 1% level at inner most (for 50  m*20cm)

12. GEANT4 Beam Delivery System simulation study at Tokyo K. Tanabe (JLC Road Map report design) Currently we have outputs (ROOT)  Using this BDS simulation, we’re going to do more detail detector BG studies

13. 2) Si  -strip intermediate tracker R&D H. Park (KNU), I.H. Park (Ewha U.), H.J. Kim (Yonsei U.), J.S.Kang, HC Ha (Korea U.) 1. Simulation 2. Design and Fabrication 3. Measurements 4. Applications in LC

14. Require good σ rΦ and σ z Reasonable (moderate) cost TypeσrΦσrΦσzσz MSGC40μm Fast Signal SSD20 μm40 μm Straw Chamber50 μm1mm Fiber Tracker50 μm1mmFast Signal Inner DC80 μm1mm Intermediate Tracker

15. 5 layers at r=9 to 37 cm angular coverage: |cosΘ|<0.9 spatial resolution: σ = 40μm thickness of a layer: 0.6% radiation length Application in LC: Intermediate Tracker CDC, 50 wires IT, 5 layers VTX, 4 layers Beam pipe e+ e- Support Tube

16. Momentum Resolution Full detector simulation 1 GeV single muon: reconstruction including energy loss and multiple scattering

17. Momentum Resolution Effect of Spatial resolution is dominant Multiple scattering, dominant - as function of spatial resolution for different energies of the incident particle

18. Design/Simulation/Fabrication of Si PIN diode Clean wafer Oxidation Cover with photoresist Expose through mask Develop Etch, Stip N + Diffusion P + Implantation Anneal Metallization P+ 0.6um N+1.0um Current High Energy Particle (1,1,1) 5 k  N-type N-sub Metal P+ Metal P+ Oxide 100  m Vf Floating N-sub Metal P+ Metal P+ Oxide 50  m VfFloating

19. Design and Fabrication wafer (500/625/380  m) - n-type high resistivity - (111) orientation - single side polished - A pad size : 1.5 x 1.4 cm 2 30um 10um

20. Leakage current : 70nA/1cm 2 at 250V Leakage Current Measurement 68nA 176nA

21. Assembly: Ladder

22. S/N Ratio Measurement Dark box Pb Photodiode sensor Beta ( 90 Sr) source

24. Heavy Ion Beam with A/Z=2, E=30GeV

25. Silicon Sensor vs dE/dx Correlation

26. Design of Si Strip

27. 700um 200 100 20000um 200 250 SiO 2 0.4um For metal contact (n + ) 0.4um Aluminum 0.3um 50um 100um n-type wafer 300um Al Design of Si Strip

28. Summary 1) Si  -strip central tracker Using GEANT4, full simulation studies have been done * Several basic parameters are studied … Vertex Detector Linking is important to reconstruct low-momentum tracks under the high magnetic field * Estimated the photon BG from IR-region … We are also working for the IR/beam-delivery system simulation using GEANT4 at Tokyo  useful for the detail BG study in Si tracker * Track-fitting.. Use Kalman filter * Track-finding.. Not yet  Need to be implemented

29. 2) Si  -strip intermediate tracker * Korean group is accumulating knowHow of SI detector * Korean group fabricated SI detector and test results showed that it is as good as others * Submitted R&D proposal for SSD in LC * Apply/extend to silicon detector (Intermediate tracker, Calorimetry) in LC * Need study momentum resolution vs # of layers, thickness, ……