Test of the MAPS add-on board S. Amar-Youcef, M. Deveaux, D. Doering, C. Müntz, S. Seddiki, P. Scharrer, Ch. Schrader, J. Stroth, T. Tischler

Outline Test setup – Mi 20 – Sensor Data analysis Results: Test MAPS add-on board Summary CBM Collaboration meeting Split / 16

Test setup Only acquisition board changed in contrast to reference system Mimosa20 (2008) Auxiliary board, power supply, signal processing, data transfer HADES-DAQ compatible, no dead time, big RAM space for data storage or buffering, 50MHz readout clock; Data processing: digitalization, sparsification Analysis Sensor Frontend board (PCB) MAPS add-on board on TRB2 (TRBnet) PC Data transfer: I/O card or OP-link Monitoring Analog signalsSync. signals CBM Collaboration meeting Split / 16

Mimosa 20 - Sensor Mimosa20 (2008): Differential analog output 2 banks 10 submatrices Multiplexed onto 2 outputs 50 MHz 200 kPixels 30 µm pixel-pitch SB pixels 30 µm C parasitic Recharge diode Collecting diode Output CBM Collaboration meeting Split / 16

Properties SB-pixel C parasitic Recharge diode Collecting diode Output I recharge I leakage Potential at output: Equilibrium: I recharge =I leakage CDS (Correlated Double Sampling): Noise CBM Collaboration meeting Split 2009 Potentiometer 5 / 16

Chip slow control JTAG interface for chip settings Working point of source follower Level marker pixels Level of signals Amplification Analog buffer Differential output buffer CBM Collaboration meeting Split / 16

Clusterfinding Noise Hit-signal (Pixels over threshold) Hit-signal (Pixels over threshold) Data analysis software Data taken and stored! Import CDS Demultiplexing Data CBM Collaboration meeting Split / 16

Noise in one Pixel Entries Noise [ADC] Charge spectrum of 55-Fe source Key observables: Noise [ADC] Calibration [e - /ADC] Gain K α ( 55 Fe ) Noise [e - ] CBM Collaboration meeting Split 2009 Noise Histogramm Pixel to pixel dispersion of Noise 8 / 16

Status on last collaboration meeting We could start running this setup for a first time – Readoutchain working properly – But performance of analoge electronics not clarified Goal: Validate the board design Validate the board design Check whether we can reach aspired performance Check whether we can reach aspired performance Maximize sensitivity ↔ minimize noise Maximize sensitivity ↔ minimize noise Understand MAPS add-on board in detail Understand MAPS add-on board in detail Approach: Systematic measurements Systematic measurements Optimize settings Optimize settings CBM Collaboration meeting Split / 16

Results Results Calibration: gain f=50MHz) Each data point measured with ‚optimal‘ settings! Discharge of K α signal, due to higher recharge current at higher temperatures! CBM Collaboration meeting Split / 16

SB-Pixel: Potential at output with hit: I recharge > I leakage I recharge = I leakage I recharge < I leakage + I Signal CDS: Hit- signal At higher leakage current:  Pixel recharge faster  Hit signal smaller CBM Collaboration meeting Split / 16

Calibration: gain f=50MHz) Expected saturation value: 408 ADC = 1640 e 408 ADC = 1640 e - CBM Collaboration meeting Split / 16

Noise w.r.t. chip temperature: CBM Collaboration meeting Split / 16

Noise w.r.t. readout frequency: Conclusion: properties are comparable to reference system  The MAPS add-on board is working well! CBM Collaboration meeting Split / 16

Status now Full control of the chip – Understand the behaviour by tuning the different parameters – Know how to balance the parameter against each other in order to optimize the noise Results match the design goals CBM Collaboration meeting Split / 16

Summary MAPS add-on board – Working well – Understand how to control the Mi20 with – Ready for beamtime Further steps: – Prepare setup and software for upcoming beamtime Thank you! CBM Collaboration meeting Split / 16

Backup slides CBM Collaboration meeting Split / 16

CBM Collaboration meeting Split 2009 U-I – characteristics of diode: Non-linear behaviour 18 / 16