slide1 n.
Download
Skip this Video
Loading SlideShow in 5 Seconds..
Camera and electronics Manel Martinez and Pascal Vincent on behalf of the PowerPoint Presentation
Download Presentation
Camera and electronics Manel Martinez and Pascal Vincent on behalf of the

Loading in 2 Seconds...

play fullscreen
1 / 22

Camera and electronics Manel Martinez and Pascal Vincent on behalf of the - PowerPoint PPT Presentation


  • 111 Views
  • Uploaded on

C herenkov T elescope A rray. Robert Bazer-Bachi Stella Bradbury Osvaldo Catalano Gerard Fontaine Florian Goebel Philippe Goret German Hermann Eckart Lorenz Manel Martinez Razmik Mirzoyan Jelena Ninkovic Nepomuk Otte Riccardo Paoletti Bernard Peyaud Michael Punch Joachim Rose

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'Camera and electronics Manel Martinez and Pascal Vincent on behalf of the' - aram


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
slide1

Cherenkov Telescope Array

Robert Bazer-Bachi

Stella Bradbury

Osvaldo Catalano

Gerard Fontaine

Florian Goebel

Philippe Goret

German Hermann

Eckart Lorenz

Manel Martinez

Razmik Mirzoyan

Jelena Ninkovic

Nepomuk Otte

Riccardo Paoletti

Bernard Peyaud

Michael Punch

Joachim Rose

Thomas Schweizer

Jean-Paul Tavernet

Masahiro Teshima

Nicola Turini

Pascal Vincent

Camera and electronics

Manel Martinez and Pascal Vincent

on behalf of the

Camera Working Group

slide2

Basic considerations

“… detection technique is well

understood and very mature …”

“… design based on proven technology …

… future upgrades possible.”

slide3

Layout

30-50 telescopes

10000 m2 mirror area

50 m2 photo sensitive area

50k-100k electronics channels

Possibly mix of telescopes (5m, 14m, 28m)

with only factor of 10 in € ($, £, ¥ …)

slide4

Thecamera

Acquisition

Light concentrator

and

Photon detector

Readout

Funding

Mechanics

Trigger

slide5

Photon detectors

Classical PMT

but

aging

low gain

high voltage

cost

Better QE, resolution …

HEPP

Neutrino

HEPP

HPD

Air shower

SiPM

Promising

but

R&D

dark current

dynamic

crosstalk

Industry

Cherenkov telescopes

Air Fluorescence

HEPP

slide6

Photon detectors

Traditional photomultipliers seem to be the most appropriate candidates for a design study. It’s a mature technology at low cost.

But the design of future cameras (electronics and mechanics) should take into account the possible success in new photon detector R&D. It should assume flexibility.

The photomultiplier technology is mature but nevertheless quite some improvements are possible.

slide7

PhotoMultiplier Tubes

  • Improvements of Classical PMT
  • Higher QE alkaline photo cathodes.
  • Reduction of after pulses.
  • Improved electron optics in the PMT (photoelectron collection efficiency, uniform gain over the first dynode and very small transit time spread).
  • d) Better separation of single photoelectron from system noise.
  • Operation at lower gain (2-5x103) by a low number of dynodes in order to cope with high background light levels and to reduce aging effects (operate during partial moonshine). High quality preamps to compensate for the low gain of few dynode PMT
  • Dynode structures to conserve very narrow pulse structures (pulses with < 1 nanosecond FWHM)
  • Compact geometry with hemispherical cathodes
  • Lowering of the necessary HV for a fixed gain (by increasing the gain/dynode) and use of low power consumption HT units nevertheless able to provide reasonably high peak pulses.
  • Smart HV controllers to protect automatically against adverse high level light background
  • Integration of peripheral electronics (HV, divider, preamp) to compact units of low power in order to decrease the camera power and the needed cooling power and zero background emission causing EMI on neighboring elements
  • Improvement of peripheral increase of the QE by means of scattering lacquer coatings or other means of cathode window surface treatment to enhance the chance of multiple photon passage of semitransparent photo cathodes.
  • Making secondary surfaces highly reflective in the front-end area
  • Minimization of backscatter losses of the first dynode.
slide8

2’’

3’’

2’’

Improvements of Classical PMT

Some progress has been achieved recently

Tested by MPIK Munich

slide10

Wavelengthshifters

Enhance the photon conversion by shifting wavelength to more efficient bandwidth region.

slide11

Light concentrator

Light collector reflectivity 85 %

Angular cutoff corresponding to the size of the mirror

Active area coverage >95%

Needed : development of light collectors with practical enhanced reflectivity and nearly zero dead area between pixels.

slide12

Electronics

Assuming 50k-100k channels readout electronics:

Pulse shape information readout window, time of signal arrival, amplitude/charge of the signal

Digitization number bits does match 5 000 photo-electron dynamic range

Single photo-electron resolution peak/valley ≥ 1.5

Dead time at 10 kHz few % (<10%)

Input band width bigger than the pulse shape frequency

Sampling rate to be define with MC and measurement ?

Crosstalk no

Electronic noises much less than the single photo-electron

Electronic power consumption = 3.1 W/channel

Programmable trigger

Environmental robustness yes

Stability of operation signal calibrated at 2%

Temperature stability

Complexity of installation few days to full performance

Modularity -

Reliability <5% dead channel with <10 person days maintenance per year

Mass production

Reproducibility

Manpower for characterization and monitoring less than 2 persons

€/channel (from PM to net) 500 – 1 000 € / channel +- ?

slide13

GHz sampling analog memory

ADC

FIFO

256-1024 ns memory depth

Flash ADC

Digital memory

μs … ms memory depth

Readout technology

Mainly two proven solutions :

Trigger

slide14

Readout technology

New electronics components, specially dedicated to Cherenkov technique, are now developed and produced.

SAM (HESS II)

Domino (MAGIC II)

Power consumption 300-35 mW

Analogue bandwidth 250-300 MHz

Dynamic range > 11 bits

Integral non linearity < 1%

Readout time 1.4 μs (for 16 ns signal)

Crosstalk < 3‰

Total noise 0.8 mV rms

Maximum readout frequency > 400 kHz

Sampling Frequency Range up to 4 GHz

Number of channels 2-10

Number of cells 256-1024

Maximum signal amplitude > 2 V

More sophisticated ASIC are still under study to equip the front end

part of the electronics.

slide15

Trigger

Different strategies have been developed

Sectors (HESS I)

Cluster (MAGIC)

first Neighbors

second Neighbors

Sector + Neighboring (HESS II)

based on usage of comparator (HESS) or discriminator (MAGIC/SPC) for the treatment of the analogue signal. Simulations needed to define the most appropriated strategy.

Also dedicated chip has been developed for L1 and L2 triggering (HESS II).

slide16

Acquisition

Two different standards are currently used in Cherenkov technique.

CompactPCI (HESS)

VME (MAGIC)

With the development of dedicated electronics cards.

slide17

Mechanics

  • Mechanics should be :
  • Compact
    • built and fully tested in a lab before installation on site (few days).
  • Modularity
    • <5% dead channel with <10 person days maintenance per year.
  • Adapt new technology and photon detectors
  • Low weight
  • Cheap
slide18

Mechanics

  • Embedded camera with fully integrated electronics has advantages :
    • allows full construction and test in laboratory
    • local treatment faster with integrated electronics
    • and minimize the signal distortion
    • allows a complete monitoring and slow control of the system
    • limit the number of connections
    • facilitates the installation and maintenance
  • For light carbon structure telescopes new
  • materials can be studied to reduce weight.
  • With camera unload facility one can imagine
  • to have spare camera to allow regular maintenance.
slide19

Cost

For a system of :

50 m2 photo sensitive area

50k-100k electronics channels

Cost per channel should be of the order of 500 €, well above what we do. We can imagine 1 k€ for some units for more sophisticated data (pulse shape, timing information …).

Homogenous system or few design made from the same building block

Mass production

Construction shared by many laboratories (opposite to Airbus)

slide20

LOI

ETC

slide21

Conclusions

  • Optimization of design is needed:
    • Improvement of photomultiplier tubes (+ wavelength shifters). Light concentrators with better transmission. In parallel we may keep an eye on new photon detector.
    • Electronics :
      • Development of new ASIC to integrate readout (analogue memories + ADC + data buffering + …).
      • Dedicated chip for trigger or other purpose.
      • Define standard for acquisition design
    • Study of new materials for the mechanics
    • Simulations (light collection, trigger, resolution …)
  • These studies could be achieved in a 2-3 years program.
  • The only R&D is for the cost.
slide22

Cherenkov Telescope Array

Thank you

Robert Bazer-Bachi, Stella Bradbury, Osvaldo Catalano, Gerard Fontaine, Florian Goebel, Philippe Goret, German Hermann, Eckart Lorenz, Manel Martinez, Razmik Mirzoyan, Jelena Ninkovic, Nepomuk Otte, Riccardo Paoletti, Bernard Peyaud, Michael Punch, Joachim Rose, Thomas Schweizer, Jean-Paul Tavernet, Masahiro Teshima,

Nicola Turini, Pascal Vincent