VC Feb 2010Slide 1 EMR Construction Status o General Design o Electronics o Cosmics test Jean-Sebastien Graulich, Geneva

EMR General Design  EMR: Electron Muon Ranger  EMR is needed to supplement KL for Downstream PID (  /e separation)  EMR is a ~1 tone Fully Active Scintillator Detector: 0.8x1x1 m 3 highly segmented in x, y and z  In addition to PID, it’s able to measure the muon momentum with a resolution of 2.5 MeV/c much better than the spectrometer at low p T  For detailed description, refer to Frank’s talk at last VC VC Feb 2010Slide 2

VC Feb 2010Slide 3 Daniela Lietti CM25

Electronics  Each bar is read out on both side but with independent chains  Digital readout Each bar is connected to one pixel of a 64 channels MultiAnode PMT The PMT is connected to a Front End Board (FEB) where the signal is amplified and then discriminated The logic signal from the FEB is sampled by a Digitizer and Buffer Card (DBC) The DBC stores the data for the entire duration of the spill The DBC is read out through a VME Controller card at the end of the spill  Analog readout On the other side All the fibers from each are bunched together and coupled to a single 1” PMT The output of the PMT is connected to one channel of a 500 MHz sampling ADC (CAEN V1731) The data is buffered in the ADC and readout at the end of the spill VC Feb 2010Slide 4

VC Feb 2010Slide 5

Electronics Status  FEB Designed and produced by Trieste/Como Based on existing FEB for another experiment AD) Recently modified and tested to use the MAROC amplifier/discriminator chip (instead of Gamma Medica/Ideas VA64TAP)  Digitizer and Buffer Card Design in progress in Geneva  VME Controller Based on general purpose VME board provided by Trieste/Como  Clock and Trigger distribution Under discussion  Sampling ADCs In hand in Geneva VC Feb 2010Slide 6

Cosmics Test  One full module (2 layers) operational in Geneva  DAQ provided by Como/Trieste  Many Thanks to Daniela Lietti and Davide Bolognini VC Feb 2010Slide 7 2 X-Y Silicon strip detectors 10x10 cm 2 Trigger Scintillator 10x10 cm 2 2 EMR Layers

The first EMR Module VC Feb 2010Slide 8 X Y Single anode PMT All fibers bunched FEB (old design)

Analysis – Prerequisite  Using the prototype Front-End Board based on the VA64TAP chip Need to scan the sampling time to determine our working point VC Feb 2010Slide 9

Tracking  Selecting single events in the Si-Array, the track are extrapolated to the EMR position -> Residuals look OK Strong evidence for cross talk (for this prototype we use of 2 x 0.8 mm fibers instead of a single 1.2 mm fiber) VC Feb 2010Slide 10 Neighbor channels on the fiber mask

Spatial Correlation VC Feb 2010Slide 11 PM1 PM0 Low value → bad coupling or problem with the ASIC channel? Inversion of one of the two fibers of each channel

Efficiency Calculation VC Feb 2010Slide 12 Extrapolate the tracks to the EMR planes Identify the fiducial surface used for the computation of efficiency ( Limited by statistics) Efficiency calculated with both single - and multi - cluster events To define the cluster: cut on the PH Two clusters are considered as separated if the two maxima are separated of at least 2 bars

Measured Efficiency VC Feb 2010Slide 13 PM0 ACROSS THE BARS AVERAGE ALONG THE BAR PM1

Overall Homogeneity Analysis performed by Michela Prest in Como VC Feb 2010Slide 14 There is a 2% difference in efficiency between the two planes. Under investigation. Probably due to crosstalk contribution (TBC) These values do not change with hold time → intrinsic efficiency? An independent analysis is being performed by Havard Wisting at Univ. of Geneva

Cosmics test Summary  Currently taking data at about 3 Hz  Preliminary average efficiency is 93.5 %  Next Steps Integrate the single PMT readout in the DAQ Need to migrate from SBS Bit3 to CAEN VME-PCi interface first Refine Efficiency Measurement Optical grease for better optical connection Green Enhanced MA-PMTs Test flex connectors needed for final assembly Define test procedure for QA during production VC Feb 2010Slide 15

Project Plan  Running full speed, we need 6 working days to produce 1 module (2 layers) => Production time: 7 months  EMR production should end in September 2010  Digitalization and Buffer card design test and production Estimated to 6 months Current design doesn’t allow mounting electronics after assembly -> New design under study  We are considering a partial delivery to RAL this summer in order to have an early test of integration in the DAQ VC Feb 2010Slide 16