Amsterdam 29 March 2011

Fernando UrbanoIFIC (CSIC – Universidad de Valencia)

KM3NeT Optical CalibrationLaser Beacon and Nanobeacon Status

KM3NeT TIME CALIBRATION PROPOSAL(Reminder)

Decoupling within the same D.U. (intra- D.U.) and between D.U. (inter-D.U.) calibration systems

INTRA D.U. Calibration:

Two Nanobeacon per DOM. Looking upwards and downwards- Less expensive and high redundancy - Either external or internal trigger- Frequency of several kHz depending on the DAQ system (300 Hz @ ANTARES)- Avoid cumbersome synchronization process, only one LED per Nanobeacon

INTER D.U. Calibration:

Laser Beacons @ 532 nm- Higher in intensity and shorter pulses < 1 ns- No synchronization needed- More expensive but less redundancy required- Tunable by Liquid Crystal Optical attenuator - Collimated beam -> Diffusion device needed

Decoupling within the same D.U. (intra- D.U.) and between D.U. (inter-D.U.) calibration systems

INTRA D.U. Calibration:

Two Nanobeacon per DOM. Looking upwards and downwards- Less expensive and high redundancy - Either external or internal trigger- Frequency of several kHz depending on the DAQ system (300 Hz @ ANTARES)- Avoid cumbersome synchronization process, only one LED per Nanobeacon

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KM3NeT TIME CALIBRATION PROPOSAL(Reminder)

NANOBEACON STATUS - ELECTRONICS

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NANOBEACON STATUS - ELECTRONICS

INPUTS OUTPUTS

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NANOBEACON STATUS - PPM

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The Nanobeacon will be

included in 4 of the DOM

allocated in the 2 active

storeys of the PPM

(Storey 20 and 19).

Nanobeacons of storey

20 will look horizontally

to the other DOM in the

same storey.

NANOBEACON – PPM OPENING ANGLE

40m

3 m

A 15°opening angle

is sufficient to

illuminate OMs

above the beacon

even in

perpendicular

arrangement

including potential

misalignment

NANOBEACON STATUS - PPM

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Regarding the

Nanobeacons it would be

better to have the second

active storey in position 17

instead of 19.

If possible this option is

recommended by us.

BEST OPTION FOR NANOBEACON TEST

NANOBEACON – PPM PLANNING

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PLANNING Specifications 05/04/2011 Interface definition with CLB 05/04/2011

LED Pulser and Control board

Study – already doneSchematic and layout 05/04/2011 purchase/manufacture 25/04/2011 Tests 13/05/2011 Ready for integration 20/05/2011

NANOBEACON STATUS – NEMO TOWER PHASE 2

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• The installation of some Nanobeacons on the NEMO

Tower to be deployed this summer at Capo Pasero

has been approved by the NEMO Technical board.

• Work to adapt the Nanobeacon, mechanically and

electronically, to the Nemo Experiment are under way.

• The final number of Nanobeacon is not decided yet.

NANOBEACON STATUS – NEMO TOWER PHASE 2

Nanobeacon mechanics (ONLY FOR NEMO):

Two pieces in PVC:

1.- Glued to the glass sphere (fixed) 2.- Screwed (in) to the first one:

Holds the LED + Electronics Protects the PMT from the Nano-Beacon light Easy to be replaced

NANOBEACON STATUS – NEMO TOWER PHASE 2

MECHANICAL SUPPORT

PULSER

CONTROL BOARD

LASER BEACON – COMPONENTS

Titanium Container

Attenuator

LASER

Anti-Biofuling System

Slow Control Inteface

Photodiode Signal

Connector

LASER BEACON -CONTAINER

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Density (×1000 kg/m3)

4.43

Poisson's Ratio 0.342

Elastic Modulus (GPa)

113.8

Cylinder of 542 mm long, with a diameter of 142 mm that holds the laser, the liquid crystal optical attenuator and the electronics.

It is made of Titanium grade 5 (Ti6Al4V)

LASER BEACON – NEMO PHASE 2

• One laser is going to be deployed in NEMO PHASE 2• A complete different electronics has been developed as:

Only RS-232 connection available There is a power limitation: 12 V @ 200 mA which has been overcome with a

battery system Read-out of the internal photodiode removed for simplicity

•The laser is a STG-03E-1S0 from Teemphotonics which emits light with a wavelength of 532 nm after frequency doubling of the original Nd-YAG wavelength of 1064 nm.

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Pulse Width (ps) 400

Energy / Pulse (μJ) 3.5

Peak Power (kW) 10

Repetition rate (kHz) 0.01 - 2

Average Power (mW) ≤ 7

LASER BEACON – KM3NeT

• A more powerful laser is under study. Selected model PNG-B02010

• A different container will be probably needed

• Completelly different electronics from the Nemo one.

• Photodiode signal read-out really important

•Also research with blue lasers is ongoing.

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Conclusions

• INTRA DU Calibration. Nanobeacon

• 4 Nanobeacons on 2 Active Storeys of the PPM

• Several Nanobeacons on the NEMO Phase 2

• Last design: supply, LVDS trigger and jitter signal improved

• Final frequency range depens on the DAQ

• INTER DU Calibration. Laser beacon

• Laser Beacon ready to be integrated in NEMO Phase 2

• Looking for a more powerful green and blue lasers for KM3NeT

• New design of electronics and Titanium container will be needed

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TIME CALIBRATION PROPOSAL

THANKS FOR YOUR ATTENTION!

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KM3NeT LASER STUDIES - SPECTRUM

Measurements carried out with the Spectrometer Ocean Optics HR4000

Both Lasers of Teemphotonics, present the main spectrum at 532 nm as expected

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KM3NeT LASER STUDIES - SPECTRUM

Measurements of an ALPHALAS, GmbH blue laser

Present 3 peaks @ 485 nm, 808 nm and 945 nm

The undesired emission peaks must be filtered out:

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LASER STABILITY

The lasers @ 532 nm are quite stable

The laser @ 485 nm is not so stable

More tests are under progress to determine is the instability is due to the 485 nm emission or to the infrared peaks @ 808 nm and 945 nm

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