DIAMOND ACTIVITIES DESY Zeuthen Wolfgang Lange

MOTIVATION and PEOPLE: Calorimetry in an environment with high radiation doses (TESLA beam cal) Beam diagnostics (photoinjector test facility Zeuthen) Currently 2 physicists (part of their time) 1 PhD student (2 soon?) 1 Postdoc (applications now checked) Support from ‘applying’ groups like Photoinjector…

Small group, few people: search for potential collaborators under the headline: Who does apply or produce diamonds? DESY HH, GSI Darmstadt, IAP Freiburg GPI Moscow, JINR Dubna CERN / existing collaborations? Diamond material from E6 Decision: learning by doing… How did we start?

Prototyping of sensors from different manufacturers: IAP, GPI, E6 –IAP: polycrystalline samples with different finishing and treatment –GPI: polycrystalline samples –2 samples bought from E6 --> INVESTIGATION OF PROPERTIES Our Program

MEASUREMENTS: DC measurements: we found ohmic behavior, hysteresis effects, nonohmic (nonlinear) effects, search for correlation with other sensor properties…

MORE ON MEASUREMENTS: Diamond Keithley 487 HV N2N2 - Extremely low currents: -> dry N 2 atmosphere and well isolating materials - settling times, relaxation

SIGNALS: & Gate PA discr delay ADC Sr 90 PM1 PM2 diamond Scint. Lab in Zeuthen -> more data required -> test run

TEST BEAM (low rate) : MIP in a 5 GeV/c Test beam (T7)

TEST BEAM (high intensity) : Sensor with negative bias 5 GeV/c test beam (T7) Sensor with positive bias 5 GeV/c test beam (T7)

TEST BEAM (structured sensor) : Sensor (1 cm 2 ) with structure: 4 (2*2) pads 5 GeV/c (T7) 2 pads parallel (yellow) 2 individual Scintillator for Calibration (green)

PLANS AND FUTURE Improved sensors (CCD), use of different analysis methods -> search for correlation with sensor properties Better understanding of observed effects Try to instrument larger areas (cal) R&D of readout technologies Prototyping of a calorimeter segment and of beam diagnostic sensors