270 likes | 446 Views
A portable readout system for microstrip silicon sensors (ALIBAVA). 3th Workshop on Advanced Silicon Radiation Detectors, 14-16 April, Barcelona, Spain. Ricardo Marco-Hernández. IFIC(CSIC-Universidad de Valencia) 1.
E N D
A portable readout system for microstrip silicon sensors (ALIBAVA) 3th Workshop on Advanced Silicon Radiation Detectors, 14-16 April, Barcelona, Spain Ricardo Marco-Hernández IFIC(CSIC-Universidad de Valencia) 1 A portable readout system for microstrip silicon sensors (ALIBAVA) Bernabeu, J.a, Casse, G.b, García, C.a, Greenall, A.b, Lacasta, C.a, Lozano, M.c, Marco-Hernández, R.a, Martí i García, S.a, Martinez, R.bMiñano, M.a, Pellegrini, G.c, Smith, N. A.b, Ullán, M.c a Instituto de Física Corpuscular (IFIC), Universidad de Valencia-CSIC,Valencia, Spain. b Department of Physics, Oliver Lodge Laboratory, University of Liverpool, Liverpool, UK. c Instituto de Microelectrónica de Barcelona, IMB-CNM, CSIC, Barcelona, Spain
A portable readout system for microstrip silicon sensors (ALIBAVA) 3th Workshop on Advanced Silicon Radiation Detectors, 14-16 April, Barcelona, Spain Ricardo Marco-Hernández IFIC(CSIC-Universidad de Valencia) 2 Outline • Motivations. • System requirements. • System architecture. • Daughter board: • Block diagram. • Beetle chip. • Fan-ins. • Mother board: • Block diagram. • FPGA logic. • System operation. • PC software characteristics. • Calibration measurements. • Measurements with laser setup. • Measurements with β source. • Conclusions and outlook.
A portable readout system for microstrip silicon sensors (ALIBAVA) 3th Workshop on Advanced Silicon Radiation Detectors, 14-16 April, Barcelona, Spain Ricardo Marco-Hernández IFIC(CSIC-Universidad de Valencia) 3 Motivations • Study the main properties of highly irradiated microstrip silicon sensors: SLHC. • Particularly the collected charge: detector performance. • Difficulty for obtaining this type of measurements: • Required equipment is expensive. • A large number of channels has to be measured. • There is minimum standardization. • Testing with an electronic system as similar as possible to those used at LHC experiments: a LHC front end readout chip should be used. • Analogue readout is preferred for accurate pulse shape reconstruction.
A portable readout system for microstrip silicon sensors (ALIBAVA) 3th Workshop on Advanced Silicon Radiation Detectors, 14-16 April, Barcelona, Spain Ricardo Marco-Hernández IFIC(CSIC-Universidad de Valencia) 4 System requirements • A compact and portable system. • The system will be used with two different laboratory setups: • Radioactive source: external trigger input from one or two photomultipliers. Alternatively a digital trigger input as well (from an external discriminator). • Laser system: synchronized trigger output generated internally for pulsing an external excitation source. • The system should contain two front-end readout chips (Beetle chip used in LHCb) to acquire the detector signals. • USB communication with a PC which will store and will process the data acquired. • System control from a PC software application in communication with a FPGA which will interpret and will execute the orders. • Own supply system from AC mains.
A portable readout system for microstrip silicon sensors (ALIBAVA) 3th Workshop on Advanced Silicon Radiation Detectors, 14-16 April, Barcelona, Spain Ricardo Marco-Hernández IFIC(CSIC-Universidad de Valencia) 5 System requirements • A compact and portable system. • The system will be used with two different laboratory setups: • Radioactive source: external trigger input from one or two photomultipliers • Laser system: synchronized trigger output generated internally for pulsing an external excitation source. • The system should contain two front-end readout chips (Beetle chip used in LHCb) to acquire the detector signals. • USB communication with a PC which will store and will process the data acquired. • System control from a PC software application in communication with a FPGA which will interpret and will execute the orders. • Own supply system from AC mains. The main goal is reconstructing the analogue pulse shape from the readout chip front-end with the highest fidelity from the acquired data.
A readout system for microstrip silicon sensors (ALIBAVA) 3th Workshop on Advanced Silicon Radiation Detectors, 14-16 April, Barcelona, Spain Ricardo Marco-Hernández IFIC(CSIC-Universidad de Valencia) 6 System architecture • Two main parts: software part (PC) and hardware part. • Hardware part: a dual board based system. • Mother board intended: • To process the analogue data that comes from the readout chips. • To process the trigger input signal in case of radioactive source setup or to generate a trigger signal if a laser setup is used. • To control the hardware part. • To communicate with a PC via USB. • Daughter board : • It will be a small board. • It will contain two Beetle readout chips • It will have fan-ins and detector support to interface the sensors. • Software part: • It will control the whole system (configuration, calibration and acquisition). • It will generate an output file for further data processing.
A readout system for microstrip silicon sensors (ALIBAVA) 3th Workshop on Advanced Silicon Radiation Detectors, 14-16 April, Barcelona, Spain Ricardo Marco-Hernández IFIC(CSIC-Universidad de Valencia) 7 Daughter board: block diagram • Two Beetle readout chips in parallel mode (256 input channels). • A buffer stage for each analogue output of the Beetle chips: • Differential current to differential voltage buffer (AD8132) implemented. • Buffered signals are sent to the mother board with impedance matched. • Fast control (LVDS signals) and slow control (I2C bus) shared by Beetle chips. • A thermistor (NTC) for sensing the temperature close to the Beetle chips. • Low voltage DC level (5 V) for Beetle chips (2.5 V) and buffer stage power supply (3 V). • High voltage DC level for silicon detector(s) bias through a power lemo connector. • Fan-ins and detector board.
A readout system for microstrip silicon sensors (ALIBAVA) 3th Workshop on Advanced Silicon Radiation Detectors, 14-16 April, Barcelona, Spain Ricardo Marco-Hernández IFIC(CSIC-Universidad de Valencia) 8 Daughter board: Beetle chip • Readout chip developed at ASIC laboratory of the University of Heildelberg. • Front-end output signal: signal that will be reconstructed from analogue readout onto one port. • This signal is sampled into the analogue pipeline (128x187 cells) with the frequency of the Beetle chip clock (40 MHz). • Vp = kQ. Tp ~ 25 ns. Total pulse length about 65-70 ns. • The analogue pipeline programmable latency fixed to 128 CLK cycles (3.2 µs). • The TRIGGER signal will have to be active 128 CLK cycles (3.2 µs) after a particular front-end signal point of interest has been sampled.
A readout system for microstrip silicon sensors (ALIBAVA) 3th Workshop on Advanced Silicon Radiation Detectors, 14-16 April, Barcelona, Spain Ricardo Marco-Hernández IFIC(CSIC-Universidad de Valencia) 9 Daughter board: Beetle chip output format • Analogue output format: single readout onto one output port. • Readout: 16 bits header + 128 analogue multiplexed channels. • Channel width of 25 ns (40 MHz clock). • DataValid signal for readout detection. • Output dynamic range: linear up to ~ ±110000 e-.
A readout system for microstrip silicon sensors (ALIBAVA) 3th Workshop on Advanced Silicon Radiation Detectors, 14-16 April, Barcelona, Spain Ricardo Marco-Hernández IFIC(CSIC-Universidad de Valencia) 10 Daughter board: detector support • Fan-ins: • Three fan-ins: chip fan-in, intermediate fan-in and detector fan-in. • Each fan-in has pads of 80 um pitch not staggered and 10 rows for multiple wire bonding. • Text-box: • Daughter board and detector boards are fixed to base plate for facilitating wire-bonding. • Two flavours of detector board exist: • Small, for 1cm2 sensors (board dimensions ~37mm x 32mm). • Large, for 1cm x 3cm sensors (board dimensions ~37mm x 50mm).
A readout system for microstrip silicon sensors (ALIBAVA) 3th Workshop on Advanced Silicon Radiation Detectors, 14-16 April, Barcelona, Spain Ricardo Marco-Hernández IFIC(CSIC-Universidad de Valencia) 11 Mother board: block diagram • Signal conditioning block transforms the differential voltage analogue input signal from each Beetle to: • Drive an oscilloscope: single ended signal. • Drive ADC: differential input shifted signal. • ADC (one for each Beetle): • 10 bit flash type with a sample rate of 40 MHz (MAX1448). • Nominal resolution of 1 mV (output signed code, 9 bits plus 1 sign bit). • Dynamic range will be ±512 mV.
A readout system for microstrip silicon sensors (ALIBAVA) 3th Workshop on Advanced Silicon Radiation Detectors, 14-16 April, Barcelona, Spain Ricardo Marco-Hernández IFIC(CSIC-Universidad de Valencia) 12 Mother board: block diagram • In case of radioactive source setup for obtaining a time stamp of each trigger. • Trigger conditioning: • Leading-edge discrimination for two photomultiplier analogue input signals. • Level conversion for an auxiliary signal (current or voltage). • Two dual LVPECL high speed comparators (MAX9601). • Four programmable voltage thresholds: generated with a quad 12 bits DAC (DAC7614). • TDC: measurement of t between input trigger and a periodic reference signal (100 ns). • A TDC integrated circuit (TDC-GP1). • Nominal resolution: 600 ps. • 100 ns dynamic range.
A readout system for microstrip silicon sensors (ALIBAVA) 3th Workshop on Advanced Silicon Radiation Detectors, 14-16 April, Barcelona, Spain Programmable delay Ricardo Marco-Hernández IFIC(CSIC-Universidad de Valencia) 13 Mother board: block diagram • In case of laser setup. • A synchronised output trigger signal (TRIG OUT) will be generated to drive a laser source to reconstruct the Beetle front-end pulse shape. • Programmable delay circuit (3D7428): • Resolution: 1 ns. • Range: up to 255 ns. • Programmed by FPGA by serial interface. • Following this block a 50 Ω driver will be incorporated for driving a pulse generator input.
A readout system for microstrip silicon sensors (ALIBAVA) 3th Workshop on Advanced Silicon Radiation Detectors, 14-16 April, Barcelona, Spain Ricardo Marco-Hernández IFIC(CSIC-Universidad de Valencia) 14 Mother board: block diagram • SDRAM (256 Mb): for acquisition data storage. • TEMPERATURE CONVERTER: NTC thermistor signal digitalization. • SLOW CONTROL: generated directly by the FPGA. External pull-up resistors for SDA and SCL lines. • FAST CONTROL: • LVDS driver (DS90LV47A) and LVDS receiver (DS90LV48A). • Six CM noise suppressor chokes (23Z105SM). • USB: USB controller (FT245R) for USB to FIFO parallel (8 bits) bidirectional data transfer. • SUPPLY SYSTEM: • DC input (5V) from AC adapter. • Digital levels from 2 DC-DC converter (1.2 V and 3.3 V) + 1 linear regulator (2.5 V). • Analogue levels from DC-DC converter (±5V) + 1 linear regulator (3.3V). • Daughter board level from DC-DC converter (5V).
A readout system for microstrip silicon sensors (ALIBAVA) 3th Workshop on Advanced Silicon Radiation Detectors, 14-16 April, Barcelona, Spain Ricardo Marco-Hernández IFIC(CSIC-Universidad de Valencia) 15 Mother board: FPGA logic • FPGA hardware: • Xilinx Spartan-3 (XS3400-PQ208) clocked at 40 MHz. • External reset push button. • On-system configuration PROM memory. • Two LEDs for system status. • FPGA logic operation: • Custom logic blocks (VHDL) for low level hardware control. • Centralized control from a CFSM. • FPGA logic blocks: • A CFSM (Central Finite State Machine) will control the different blocks depending on the current state of the system. • Radioactive source: the DAC CONTROL, TRIGGER IN and TDC CONTROL will be used for processing the trigger inputs and obtaining a time stamp of each trigger. • Laser setup: the TRIGGER OUT block will generate the output trigger signal and will control the programmable delay circuit.
A readout system for microstrip silicon sensors (ALIBAVA) 3th Workshop on Advanced Silicon Radiation Detectors, 14-16 April, Barcelona, Spain Ricardo Marco-Hernández IFIC(CSIC-Universidad de Valencia) 16 Mother board: FPGA logic • FPGA logic blocks: • ADC CONTROL: readout of the digitized data frames when the input DataValid (fast control) signal will be active. This digitized data will be stored in a internal FIFO RAM. • BEETLE FAST CONTROL: generation of fast control signals (Clk, Trigger, Testpulse and Reset) depending on the state of the system. • BEETLE SLOW CONTROL: I2C master controller for writing/reading the Beetle internal registers (slow control) for configuration. • SDRAM CONTROL: implements a controller for interfacing the SDRAM and the CFSM. • USB CONTROL: interface between the USB controller and the CFSM. • CLOCK GENERATOR: required internal clock and reset signals generation.
A readout system for microstrip silicon sensors (ALIBAVA) 3th Workshop on Advanced Silicon Radiation Detectors, 14-16 April, Barcelona, Spain Ricardo Marco-Hernández IFIC(CSIC-Universidad de Valencia) 17 Mother board: FPGA logic • FPGA logic: • The CFSM and SDRAM CONTROL have been implemented with an embedded system (soft processor + SDRAM peripheral). • Soft processor: Microblaze (32 bits RISC) at 40 MHz. • SDRAM controller included as standard peripheral for the Microblaze. • ARBITRER : custom block of registers for communication between the embedded processor and the custom logic blocks. • FSLs (Fast Simplex Links): unidirectional FIFOs for fast communication between the ARBITRER and the Microblaze. • The functionality of the system is programmed as a standard C program in the processor (firmware): great flexibility for changes.
A readout system for microstrip silicon sensors (ALIBAVA) 3th Workshop on Advanced Silicon Radiation Detectors, 14-16 April, Barcelona, Spain Ricardo Marco-Hernández IFIC(CSIC-Universidad de Valencia) 18 Mother board: system operation • RESET: • System initialization. • With a power on, with an external reset or by software reset. • WAITING: • The system will wait for an order coming from the PC software to go to another state. • BEETLE CONFIGURATION: • Beetle chips configuration registers programming. • CALIBRATION: • System calibration by the Beetle internal test pulse generator. • Known amplitude readouts will be acquired. • TRIGGER IN CONFIGURATION: • DAC voltage thresholds will be programmed. • Trigger inputs scheme will be configured. • LASER SYHRONIZATION: • The system will be synchronized for the Beetle front end pulse reconstruction. • By delaying the TRIG OUT signal in 1 ns steps.
A readout system for microstrip silicon sensors (ALIBAVA) 3th Workshop on Advanced Silicon Radiation Detectors, 14-16 April, Barcelona, Spain Ricardo Marco-Hernández IFIC(CSIC-Universidad de Valencia) 19 Mother board: system operation • PEDESTALS, RS or LASER ACQUISITION: • A programmable number of readouts will be able to be acquired (up to 64776) and stored in the SDRAM. • PEDESTALS: For each event a Beetle chips readout (256 by 16 bits) and a temperature readout will be stored in the SDRAM. No charge acquired with Beetle chips. • RS: For each event a Beetle chips readout (256 by 16 bits), a TDC readout (32 bits) and a temperature readout will be stored in the SDRAM. • LASER: For each event a Beetle chips readout (256 by 16 bits) and a temperature readout (16 bits) will be stored in the SDRAM. The TRIG OUT frequency will be 1 KHz. • PEDESTALS, RS or LASER READING: • The last type of acquisition will be read from SDRAM and data will be sent to PC by USB.
A readout system for microstrip silicon sensors (ALIBAVA) 3th Workshop on Advanced Silicon Radiation Detectors, 14-16 April, Barcelona, Spain Ricardo Marco-Hernández IFIC(CSIC-Universidad de Valencia) 20 PC software • Functions: • Control the whole system (configuration, calibration and acquisition). • User interface with the system (GUI). • Generation of information (output files). • Two software levels: • Low level for software/mother board communication by USB: VCP (virtual com port) driver (2.4 Mb/s) used. • High level: GUI and output file generation for further processing. • Programming language: C++ • Operating system compatibility: • Linux version fully operational. • Windows beta version. • There are also macros for ROOT in order to process the data acquired with the software.
A readout system for microstrip silicon sensors (ALIBAVA) 3th Workshop on Advanced Silicon Radiation Detectors, 14-16 April, Barcelona, Spain Ricardo Marco-Hernández IFIC(CSIC-Universidad de Valencia) 21 Calibration measurements: n-type detector • Data acquired from calibration acquisition. • Beetle chip 1 (channels 1-128) without detector. • Non-irradiated n-type detector connected to Beetle chip 2 (channels 129-256). • First 14 and last 14 channels of Beetle 2 without detector: detector of 100 channels. • Some channels does not operate due ‘shorts’ at the bonds: reduced gain. • This data is used to calculate the ADC/electrons rate for each channel.
A readout system for microstrip silicon sensors (ALIBAVA) 3th Workshop on Advanced Silicon Radiation Detectors, 14-16 April, Barcelona, Spain Ricardo Marco-Hernández IFIC(CSIC-Universidad de Valencia) 22 Calibration measurements: p-type detector • Data acquired from calibration acquisition. • Beetle chip 1 (channels 1-128) without detector. • Non-irradiated p-type detector connected to Beetle chip 2 (channels 129-256). • This data is used to calculate the ADC/electrons rate for each channel.
A readout system for microstrip silicon sensors (ALIBAVA) 3th Workshop on Advanced Silicon Radiation Detectors, 14-16 April, Barcelona, Spain Ricardo Marco-Hernández IFIC(CSIC-Universidad de Valencia) 23 Measurements with laser setup: n-type detector • Data acquired by means of a laser scan. • Non-irradiated n-type detector connected to Beetle chip 2 (same conditions as on calibration). • Vbias = 200 V (full depletion). • Laser light: • Wavelength: 1060 nm (near infrared). • Laser energy of photons: 1.17 eV. • Laser scan: • Scan delay range: 1040-1140 ns. • Delay step: 1 ns. • 100 samples per step. • Some channels does not work due to bad bonds.
A readout system for microstrip silicon sensors (ALIBAVA) 3th Workshop on Advanced Silicon Radiation Detectors, 14-16 April, Barcelona, Spain Ricardo Marco-Hernández IFIC(CSIC-Universidad de Valencia) 24 Measurements with laser setup: p-type detector • Data acquired by means of a laser scan. • Non-irradiated p-type detector connected to Beetle chip 2 (same conditions as on calibration). • Vbias = -100 V (full depletion). • Laser light: • Wavelength: 1060 nm (near infrared). • Laser energy of photons: 1.17 eV. • Laser scan: • Scan delay range: 1040-1160 ns. • Delay step: 1 ns. • 100 samples per step. • All channels work correctly.
A readout system for microstrip silicon sensors (ALIBAVA) 3th Workshop on Advanced Silicon Radiation Detectors, 14-16 April, Barcelona, Spain Ricardo Marco-Hernández IFIC(CSIC-Universidad de Valencia) 25 Measurements with β source: n-type detector • Acquisition with β source (90Sr). • Non-irradiated n-type detector connected to Beetle chip 2 (same conditions as calibration). • Vbias = 200 V (full depletion). • Acquisition of ~ 19000 events (triggers): • Trigger input from one photomultiplier. • Threshold: -40 mV. • Some channels are noisy due to bad bonds. • Pulse peak charge corresponding ~ 1 mip (24810 e-). • Noise: ~ 1200 e-. • Common mode variations (σ= 5.88 counts) corrected by software. • SNR for peak voltage: ~ 21.
A readout system for microstrip silicon sensors (ALIBAVA) 3th Workshop on Advanced Silicon Radiation Detectors, 14-16 April, Barcelona, Spain Ricardo Marco-Hernández IFIC(CSIC-Universidad de Valencia) 26 Measurements with β source: p-type detector • Acquisition with β source (90Sr). • Non-irradiated p-type detector connected to Beetle chip 2 (same conditions as calibration). • Vbias = -100 V (full depletion). • Acquisition of 20000 events (triggers): • Trigger input from one photomultiplier. • Threshold: -40 mV. • All channels working. • Pulse peak charge corresponding ~ 1 mip (26940 e-). • Noise: ~ 1200 e-. • Common mode variations (σ= 8.9 counts) corrected by software. • SNR for peak voltage: ~ 22.
A readout system for microstrip silicon sensors (ALIBAVA) 3th Workshop on Advanced Silicon Radiation Detectors, 14-16 April, Barcelona, Spain Ricardo Marco-Hernández IFIC(CSIC-Universidad de Valencia) 27 Conclusions and outlook • The readout system has been developed and is fully operational. • The system can operate with different types and different sizes of microstrip detectors: • n-type. • p-type. • Up to 256 input channels. • Two flavours of detector boards to accommodate detectors of different sizes. • The system is designed to work with a radioactive source setup and laser setup: useful for comparing results with the same detector. • The system has been tested with laser setup and a β source: • It works correctly. • With p-type and n-type detectors. • SNR ~ 20 with non-irradiated detectors: there is room for irradiated detectors. • Currently, there is a software Linux version: in the near future, there will be a Windows version for the software (currently debugging a beta version). • Data acquired with the system can be easily processed using ROOT framework: some macros already developed. • System is ready for production and distribution (motherboards and daughterboards in stock). Production and assembly under demand. • Future work: upgrade of the system for testbeam acquisition by synchronizing various ALIBAVAs.