TRD Status ALICE Offline Week 1 9 5

TRD Status ALICE Offline Week 1. 9. - 5. 9. 2003 Christoph Blume, University of Frankfurt/M.

Geometry ● Final design of chambers ● Design of services approaching final version ● TRD geometry was moved 2 cm inwards to accomodate services – ● ● Space needed in Ali. Root mother volume Detailed implementation in Ali. Root – Supermodule frame – Power bars + cooling – FEE chips Planned to be submitted this week

Geometry Update: Frame of Supermodule

Geometry Update: ● Cooling + cabling ● FEE chips not yet final Services

Geometry Update: Front View support rail cooling arteria LV supplies cooling pipes + cables Ali. Root implementation Proposed design

Detector Response ● Bug fixes and parameter updates (Oliver Busch + Anton Andronic) – Changes submitted to TRD code (HEAD branch) – Ali. TRDsim + Ali. TRDv 1 ● – – Electrons, new Calculation of absorbtion length ● Air in gap ● Temperature dep. of Xe -electrons? ● Pions Into next layer Modification of Fermi plateau 1. 77 MP (needed) Electrons, old

Detector Response ● ● ● Momentum dependent tuning of TR simulation parameter – Good agreement to test beam data for given momentum Ken Oyama – But no overall description of momentum dependence possible Different performance in different layers – Increase of performance with layer in test beam – Propagate TR into next layer -> TR photons on particle stack for tests Additional effects, still to be investigated: – Space charge -> angular dependence (modifcation of gas gain) – Non-isochronity

Tracking ● ● Ready to commit (Sergei Sedykh): – Inner refit function – Density effect in Bethe-Bloch parametrization – Electron propagation including Bremsstrahlung (Mihai Petrovici) To be tested: – ● Inward matching TRD TPC for added TRD tracks To be developed: – – Update of tilted pad tracking. ● Currently by correction in functions of Ali. TRDtracker and Ali. TRDtrack ● Makes cluster-errors in y and z coupled and has empirical parameter ● Rotation of track parameters before and after track update to decouple them Parallel tracking (Jana Bielcikova)

Fast Simulation ● Simulation of physics signals in TRD (Tariq Mahmoud) – ● J/ and simulation for PPR Input from global tracking analysis by Thomas Kuhr – Momentum resolution + efficiency ● TRD PID from test beam data ● Adapt FASTSIM code from MUON

Online Trigger Simulation Code ● Code available and running (Bogdan Vulpescu) ● New LTU class ● ● ● Grid Production running at Karlsruhe + HIJINGparam d. N/dy = 6000 / 4000 / 2000 / 800 / 400 / 240 / 160 / 80 Software also used for evaluation of the test beam data (Christian Lippmann) http: : //www. gsi. de/~vulpescu/trigger/

TRD Status ● Geometry ● Detector response ● Tracking ● Fast simulation

Geometry Update: cross bars of supermodule frame cooling pipes cabling Side View