Timing calibration in NEMO. M. Circella Istituto Nazionale di Fisica Nucleare, Bari on behalf of the NEMO Collaboration

Transcription

1 Timing calibration in NEMO M. Circella Istituto Nazionale di Fisica Nucleare, Bari on behalf of the NEMO Collaboration

2 NEMO Telescope layout 200 m Tower 200 m 1 primary Junction Box 8 secondary Junction Boxes 64 towers 200 m grid pitch 64 PMT on each tower 4096 PMT in total 1400 m Primary JB Secondary JB Electro-optical cable to shore: 48 optical fibres 3 4 conductors

3 FCM (Floor Control Module) Floor 16 Tower Layout PMT64 20m PMT Mbps Optical Module Floor 15 Floor 14 SDH STM-1 (155 Mbps) Floor 2 Floor 1 PMT4 PMT1 PMT3 PMT2 Junction Box 150m

4 FCM (Floor Control Module) Floor 16 Tower Layout PMT64 20m PMT Mbps Optical Module Floor 15 Floor 14 SDH STM-1 (155 Mbps) Floor 2 Floor 1 PMT4 PMT1 PMT3 PMT2 Junction Box 150m DWDM mux

5 Tower Layout FCM (Floor Control Module) Mbps Floor 16 PMT64 20m PMT63 Optical Module Floor 15 Floor 14 SDH STM-1 (155 Mbps) Floor 2 DWDM communications Floor 1 (2.5 Gbps) PMT4 PMT1 PMT3 PMT2 Junction Box 150m DWDM mux

6 Front-end electronics (inside the Optical Modules) PMT Log. Compr. off1 off2 com ADC 8bit [100MHz] ADC 8bit [100MHz] DOUT clk DOUT clk FIFO Soft trigger Counter To FCM FPGA From FCM FCM interface Vcc Mbps 432 kbps Offset & Gain Lock In F C M PLLout DSP Sensors Cal. 8 Out In ADC\DAC 10bit [Slow control] JTAG SCI Flash 256kX8

7 Front-end electronics (inside the Optical Modules) PMT Log. Compr. off1 off2 com ADC 8bit [100MHz] ADC 8bit [100MHz] DOUT clk DOUT clk FIFO Soft trigger Counter To FCM FPGA From FCM FCM interface Vcc Mbps 432 kbps Offset & Gain Lock In F C M Sensors Cal. 8 PLLout Full description of the NEMO Front-End electronics in Domenico Lo Presti s and Carlo Nicolau s ADC\DAC 10bit presentations tomorrow (A2.4.1 and A2.4.3) Out In [Slow control] DSP JTAG SCI Flash 256kX8

8 Floor Control Module OM 1 Conditioning Power OM 2 OM 3 FPGA clock TBTI STM-1 Interface Tower Base OM 4 Overhead Slow Control DSP PCI Bus

9 Floor Control Module OM 1 Conditioning Power OM 2 OM 3 FPGA clock TBTI STM-1 Interface Tower Base OM 4 Slow Control DSP Overhead STM-1 Protocol (optic fibre) 155 Mbps PCI Bus

10 Floor Control SDH mapper Module (Transwitch Fast-3N) E/O/E interface (Finisar FTR-1631) OM 1 Power Conditioning OM 2 OM 3 FPGA clock TBTI STM-1 Interface Tower Base OM 4 Slow Control DSP Overhead STM-1 Protocol (optic fibre) 155 Mbps PCI Bus

11 Floor Control Module OM 1 Conditioning Power OM 2 OM 3 FPGA clock TBTI STM-1 Interface Tower Base OM 4 Slow Control DSP PCI Bus Overhead STM-1 Protocol (optic fibre) 155 Mbps STM-1 Interface Control Circuits Indipendent Bidirectional Communication between DSP and STM-1 Interface through TOH channels (E1, E2, F1, DCC)

12 Proprietary Protocol (Electric) Rx: Mbps Tx: 432 kbps Floor Control Module OM 1 Power Conditioning OM 2 OM 3 FPGA clock TBTI STM-1 Interface Tower Base OM 4 Slow Control DSP PCI Bus Overhead STM-1 Protocol (optic fibre) 155 Mbps STM-1 Interface Control Circuits Indipendent Bidirectional Communication between DSP and STM-1 Interface through TOH channels (E1, E2, F1, DCC)

13 Proprietary Protocol (Electric) Rx: Mbps Tx: 432 kbps Floor Control Module OM 1 Power Conditioning OM 2 OM 3 FPGA clock TBTI STM-1 Interface Tower Base OM 4 Sinchronous Serial (SPI) Slow Control DSP PCI Bus Overhead STM-1 Protocol (optic fibre) 155 Mbps STM-1 Interface Control Circuits Indipendent Bidirectional Communication between DSP and STM-1 Interface through TOH channels (E1, E2, F1, DCC)

14 Proprietary Protocol (Electric) Rx: Mbps Tx: 432 kbps Floor Control Module OM 1 Power Conditioning OM 2 OM 3 FPGA clock TBTI STM-1 Interface Tower Base OM 4 Sinchronous Serial (SPI) Slow Control PCI Bandwidth: 120 MBps, enough to allow real-time transmission to Host of STM-1 protocol data DSP PCI Bus Overhead STM-1 Protocol (optic fibre) 155 Mbps STM-1 Interface Control Circuits Indipendent Bidirectional Communication between DSP and STM-1 Interface through TOH channels (E1, E2, F1, DCC)

15 Proprietary Protocol (Electric) Rx: Mbps Tx: 432 kbps Floor Control Module OM 1 Power Conditioning OM 2 OM 3 FPGA clock TBTI STM-1 Interface Tower Base OM 4 Sinchronous Serial (SPI) PCI Bandwidth: 120 MBps, enough to allow real-time transmission to Host of STM-1 protocol data Slow Full description of the NEMO SDH transport in Control Fabrizio Ameli s DSP presentation later (A1.4.9) PCI Bus Overhead STM-1 Protocol (optic fibre) 155 Mbps STM-1 Interface Control Circuits Indipendent Bidirectional Communication between DSP and STM-1 Interface through TOH channels (E1, E2, F1, DCC)

16 STM-1 Payload

17 SDH STM-1 data frame 270 bytes 9 bytes 261 bytes 9 rows

18 SDH STM-1 data frame 270 bytes 9 bytes 261 bytes 9 rows

19 (DWDM) DATA TRANSPORT in NEMO 1/16 DWDM MUX from tower to shore 1/16 DWDM DEMUX Floor # 1 Tower # 1 Floor # 16 1/16 DWDM DEMUX Tower from shore to tower 1/16 DWDM MUX Shore One colour per floor (50 GHz spacing) Floor # 1 Tower # 1 Floor # 16

20 Time measurements in NEMO 1. The signals from the Optical Modules are continuously sampled at 200 MHz (by means of two staggered ADC s) 2. When a threshold value (remotely programmable through slow cont rol) is met, the over-threshold samples, plus a fixed number of pre -trigger samples, are stored in a FIFO for transmission to shore 3. The readout at the trigger time of a 16-bit 100 MHz counter is stored together with the sampled signals Synchronization in NEMO 1. The clock signal is recovered offshore (in each Floor Control Mo dule) from the SDH frames received from the onshore station 2. The SDH mapper inside the FCM recovers a low -jitter MHz clock (also used to clock out the payload data received in the SDH data frames) 3. A MHz clock is delivered from the FCM to the Optical Modul es 4. This MHz clock is fed to a PLL to give rise to the 100 MHz clock used for all front-end operations

21 Timing calibration in NEMO Two different problems: Compare the time measured in the apparatus with UTC time ( absolute timing calibration) Same problem for all neutrino telescopes Determine the offsets in local time measurements ( relative timing calibration), i.e. the propagation time of commands and clock signals from onshore to offshore Same problem for all neutrino telescopes if the digitization and time measurements are performed offshore

22 Time calibration in NEMO (the approach) Floor 16 PMT64 20m PMT63 Floor Control Module Floor 15 Floor 14 Optical Module (& FE electronics) Floor 2 Floor 1 PMT4 PMT3 PMT1 PMT2 150m Tower JB Secondary JB

23 Time calibration in NEMO (the approach) I. SDH echo calibration PMT64 20m PMT63 Floor 16 Floor Control Module Floor 15 Floor 14 Optical Module (& FE electronics) Floor 2 Floor 1 PMT4 PMT3 PMT1 PMT2 150m Tower JB Secondary JB

24 Time calibration in NEMO (the approach) I. SDH echo calibration PMT64 20m PMT63 Floor 16 Floor Control Module II. Optical calibration Floor 15 Floor 14 Optical Module (& FE electronics) Floor 2 Floor 1 PMT4 PMT3 PMT1 PMT2 150m Tower JB Secondary JB

25 Time calibration in NEMO (the approach) I. SDH echo calibration PMT64 20m PMT63 Floor 16 Floor Control Module II. Optical calibration Floor 15 Floor 14 Optical Module (& FE electronics) Floor 2 III. Shore station: It will be equipped for the SDH echo time measurements and with GPS Floor 1 PMT4 PMT1 PMT3 PMT2 150m Tower JB Secondary JB

26 The FCM interface to the timing calibration system OM 1 Conditioning Power OM 2 OM 3 FPGA clock TBTI STM-1 Interface Tower Base OM 4 Overhead Slow Control DSP PCI Bus

27 The FCM interface to the timing calibration system OM 1 Power Conditioning OM 2 OM 3 FPGA clock TBTI STM-1 Interface Tower Base OM 4 Overhead Slow Control The FPGA will sinchronously: DSP Deliver the reset signal to the time counters in the optical mo dules Deliver an echo signal to the shore station Activate the optical calibration system in response to a shore command PCI Bus

28 Optical beacons are ineffective for km 3 -scale detectors! Number of photoelectrons Distance of a PMT from the optical source

29 Optical calibration system Optical Module diffuser Optical fibre Attenuator Optical source (+ time stamp) FCM (Floor Control Module) splitter Photodiode FCM electronics interface

30 Timing calibration in NEMO: conclusions and perspectives The relative timing calibration will be performed by means of a SDH echo measurement and an optical calibration system Interface with the data trasport system under definition Different choices under study for the optical calibration syste m