DIAMOND ACTIVITIESDESY 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 othersensor properties…

MORE ON MEASUREMENTS:

Dia

mo

nd

Ke

ith

ley

48

7HV

N2

- Extremely low currents:-> dry N2 atmosphere and well isolating materials- settling times, relaxation

SIGNALS:

&

Gate

PA

discr

discr

delay

ADCSr90

PM1

PM2

diamond

Scint.

Lab in Zeuthen

-> more data required-> test run

TEST BEAM (low rate) :

MIP in a 5 GeV/cTest beam (T7)

TEST BEAM (high intensity) :

Sensor with negative bias5 GeV/c test beam (T7)

Sensor with positive bias5 GeV/c test beam (T7)

TEST BEAM (structured sensor) :Sensor (1 cm2)with structure:4 (2*2) pads5 GeV/c (T7)

2 pads parallel(yellow)2 individual

Scintillator forCalibration (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