Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Electronic engineering wikipedia , lookup
Resistive opto-isolator wikipedia , lookup
Control theory wikipedia , lookup
Dynamic range compression wikipedia , lookup
Resilient control systems wikipedia , lookup
Regenerative circuit wikipedia , lookup
Analog-to-digital converter wikipedia , lookup
Pulse-width modulation wikipedia , lookup
Time-to-digital converter wikipedia , lookup
Oscilloscope history wikipedia , lookup
Hendrik Wade Bode wikipedia , lookup
Electronics of LHCb calorimeter monitoring system A.Konoplyannikov for the LHCb Calorimeter Group Poster for Topical Workshop on Electronics for Particle Physics September 15-19, 2008, Naxos, Greece LHCb calorimeter Detectors Calorimeter System Photo-Detectors and LED monitoring Optics for precise measurements of CP violation and rare decays: for precise monitoring phototube stability All calorimeters are equipped with Hamamatsu photo tubes as devices for light to signal conversion. Eight thousand R7899-20 tubes are used for the electromagnetic and hadronic calorimeters and two hundred 64 channels multi-anode R7600 -00-M64 for Scintillator-Pad/Preshower detectors. The main aim of the calorimeter light emitting diode (LED) monitoring system is to monitor the PMT gain in time of data taking. The other important role of the system will be during the detector commissioning and testing in the LHC machine stops for PMT, cables and FE board tests and relative time alignment. Each LED of the system illuminates up to 40 tubes and total amount of the monitoring channels is about 700. PIN amplifie r PM T Phototube Parameters: • • • • • • • The aim of the LHCb experiment is to fully investigate CP violation in the Bd and Bs systems, and to possibly reveal new physics beyond the Standard model. LED driver with PIN amplifier board Number of dynodes: 10 Supply voltage: 1800 V max Average Anode Current: 0.1 mA max Quantum Efficiency: 15 % at 520 nm Current Amplification: 106 Dark Current: 2.5 nA Time Response: 2.4 ns Pulse Linearity:+- 2 % Pulse shapes of the PMT and PIN signals from LED flash and PMT 50 GeV particles. For LED light stability monitoring the PIN diode is used. The PIN diode signal after amplification is sent to the FE electronics board. 50 Gev pions Electronics of LED Monitoring System 1. LED monitoring System Overview CROC LEDTSB 2. LED driver and intensity control LED The LED intensity control voltage 3V - 12V 1 Front-End Crate SPECS slave The LED intensity signal distribution board consists of the mother card and four types of the mezzanine board: SPECS slave for interconnection with the LHCb ECS system. Control Logic board for interface between the SPECS slave and others functional parts of Distribution board. HV control signal generation mezzanine. LED control signal generation mezzanine TL072CD LED driver Simplified circuit diagram TTCrx 15 ns Air transformer Bchannel 8 Driver Shaping and overshot circuit Fast Shaper EL7212 "Flashing" pulse LVDS levels CLK Time alignment circuits PIN with Amplifier 2 PMT 6 Inner Middle Outer 5 LED The LED monitoring consists of three functional parts: Subsystem for a LED intensity control for variation of the LED intensity across a wide range includes 40 boards. 12 9U –VME bards for a LED triggering pulse control and distribution placed into the front-end crates. 700 of the LED drivers with LV power distribution. 4 3 HV_LED_DAC SPECS System Overview LED intensity control board OA FEBs Specification: Precision of the PMT gain monitoring is about 0.3 %. Individual time setting for each LED in range of 400 ns with 1 ns step. PIN diode with amplifier is used for monitoring the LED stability itself. Control Logic FPGA is placed on a mezzanine card and equipped with radiation tolerant ACTEL pro-ASIC chip APA300. Memory of the scanning algorithm FPGA with 64 patterns of the output trigger signals allows perform all needed sequences for LED flashing. The calorimeter monitoring system is linked to the LHCb ECS system by the SPECS serial bus (developed in LAL). ACT Logic DS92LV010A Produce LED signal in a wide intensity range with pulse shape similar the particle response. Peculiarities: 1) Edge triggering circuit with fast pulse shaper on the board; 2) Decoupling by air transformer LEDTSB 3. LEDTSB – 64 channels LED triggering board Scanning Algorithm Memory LED trigger pulse Channel Mask 1 Coarse Clk Phase Shifter Delay 0 - 15 ckl Back Plane of FE crate Control Logic ACTEL FPGA Broadcast Command Decoder BCALIB[3..0] SPECS Bus 64 Clk Phase Shifter Parallel Bus [16..0] Clk Phase Shifter 4 channels TDC 18 I2C Signal Shaper 32 33 34 Signal Shaper Clk Phase Shifter 16 17 Signal Shaper Signal Shaper SPECS slave Mezzanine Broadcast commands from TTCrx 2 Signal Shaper AND Coarse Delay 0 - 15 ckl 1 Signal Shaper Signal Shaper 48 49 50 Signal Shaper 40 MHz ClkBlock diagram of the LED triggering signal distribution board Main changes of LEDTSB specification: Each of 64 channels of LEDTSB is delayed Calibration signal in range up to 400 ns with 1 ns step. There is no a channel grouping now. 12.5 ns coarse delay step in range of 5 bits is implemented, that allows exclude a synchronization problem when CLK and calibration signal edges close to each other. Four TDC’s are added on the board for calibration and test purpose. Firmware for APA300 ACTEL FPGA has been developed and tested. 64 1-4 LVDS 64 output channels of the LEDTSB board is divided on four group with an individual Coarse delay up to 15 clock cycles with a time step of 25 ns. Each output channel is equipped with the shaper for synchronization with Clock and generation a pulse of 50 ns width. Detector quality monitoring & Integration into the Experiment Control System (ECS) 1. Monitoring System performance 2. ECS Software for control of the LED monitoring system LED signal scanned shapes of the HCAL module Typical LED and PMT stability ADC (cnt) Normalized amplitude 8 channels of Crate_22 (outer) and Each point corresponds of the mean value of PM amplitude for 200 events Normalized amplitude 8 channels of Crate_23 (inner) Eight tubes stability < +- 0.1 % Eight LEDs stability measured by PIN Time (ns) < +- 0.4 % Time (Hour) Performance: PMT gain monitoring with precision less then 0.3 %; LED stability monitoring by a PIN diode with precision of 0.1 %; Online visualization of the calorimeters LED response; LED monitoring system is precise tool for the detector performance study during commissioning and experiment running time. Time scan technique is used for a correct time adjustment of the LED monitoring system and checking an inter-crate synchronization. For doing the detector time alignment the automated process has been implemented to scan the LED delay from PVSS and collect data by DAQ (increment step by step the 1 ns delay of the LEDTSB). Precision and stability of the signal arriving time measurement is about of 0.3 ns. RMS = 1.16 ns Time (ns) ADC (cnt) 1% Time (min) PVSSII panels for LED monitoring system Device Unit panel of the LEDTSB triggering pulse sequence configuration PMT Stabilizing Time of about 15 min HCAL module 5 normalized ADC response vs time after HV ON. 16 Channels Device Unit panel of the LEDTSB delay triggering pulse configuration Specification: LHCb's Experiment Control System is in charge of the configuration, control and monitoring of all the components of the online system. This includes all devices in the areas of: data acquisition, detector control (ex slow controls), trigger, timing and the interaction with the outside world. The control framework of the LHCb is based on a SCADA (Supervisory Control and Data Acquisition) system called PVSSII. Which provides the following main components and tools: •A run time database •Archiving •Alarm Generation & Handling •A Graphical Editor •A Scripting Language •A Graphical Parameterization tool Time and amplitude distributions of the PMT response on LED for HCAL A side. Control and monitoring parameters: The LEDTSB and LED intencity boards configuring is performed by standard FSM way. In the same time to prepare or modify a recipe one needs a mechanism to update a recipe content. The LEDTSB half Configuration panel allows to load new values from the configuration files or from the dedicated CALO Data Base. The LEDTSB parameters could be modified and with using the expert LEDTSB panels too. After updating the recipe content one can save the recipe with specified name. Panel of the HCAL LED intensity configuration