concept idea for a future telescope array observatory
Download
Skip this Video
Download Presentation
Concept idea for a future telescope array observatory

Loading in 2 Seconds...

play fullscreen
1 / 12

Concept idea for a future telescope array observatory - PowerPoint PPT Presentation


  • 97 Views
  • Uploaded on

Concept idea for a future telescope array observatory. CTA meeting Berlin May 4-5, 2006 Thomas Schweizer. Goals and constraints. Specification of CTA observatory Energy range 10 GeV to 100 TeV Available budget: 100-150 Mio Euro Sensitivity ~ 5-10 times better than previous instruments

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 ' Concept idea for a future telescope array observatory' - kael


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
concept idea for a future telescope array observatory

Concept idea for a future telescope arrayobservatory

CTA meeting Berlin

May 4-5, 2006

Thomas Schweizer

May 4-5, 2006 T.Schweizer, CTA meeting Berlin

goals and constraints
Goals and constraints
  • Specification of CTA observatory
    • Energy range 10 GeV to 100 TeV
    • Available budget: 100-150 Mio Euro
    • Sensitivity ~ 5-10 times better than previous instruments
  • It is impossible to span 7 orders of magnitude (10 GeV - 100 TeV)by one single detector and keep optimal performance (because of limited dynamic range and steep spectra)
    • One array 10 GeV to 1 TeV (LEA)
      • low energy threshold, ~10-20 large telescopes
      • 75 % of budget (North and South)
    • One array 1 TeV up to 100 TeV (ULTRA II)
      • very large effective area, ~100-150 small telescopes
      • 25 % of budget (only South)
      • E. Lorentz talk

May 4-5, 2006 T.Schweizer, CTA meeting Berlin

two arrays together
Two arrays together
  • Overlap in energy between both arrays for cross-calibration- Simultanous observation with small and large array- Parallel observation of several sources with parts of array- Longterm monitoring of sources with single telescopes

Lowest possible energy threshold

and highest sensitivity

1-2 km2, large eff. area

May 4-5, 2006 T.Schweizer, CTA meeting Berlin

low energy array lea
Low energy array (LEA)
  • What do we want for available budget (~70 Mio Euro) ?
    • As many telescopes as possible for high sensitivity and parallel observation of sources
    • As low energy threshold as possible
  • Possibilities:
    • 30 m telescopes (710 m2 mirror) with classical PMTs
    • 23 m telescope (415 m2 mirror) with SiPM light sensors
  • 23 m telescope
    • Increase in photon-detection efficiency rather than mirror area high mirror reflectivity (90%), high QE (SiPM, 50%)
    • Smallertelescopes and lighter telescopes are cheaper, < 120 tons weight, 70 tons possible
    • Big question: is it possible to build 16-20 telscopesfor 70 Mio Euros ?

May 4-5, 2006 T.Schweizer, CTA meeting Berlin

possible telescope parameters
Possible telescope parameters

Active mirror control with improved optical

quality (PSF)

  • FOV=5°
  • F/D = 1.2:
  • acceptable aberation (5° FOV)

D= 23 m diameter

parabolc mirror

 430 m2

F= 28 m

  • Protection against
  • wind lift-up
  • Lighter & cheaper telescope

May 4-5, 2006 T.Schweizer, CTA meeting Berlin

possible parameters for camera design
Possible parameters for camera design

FOV 5°

  • D= 2.4 m
  • A=4.5 m2
  • Roundish camera, FOV 5°
  • Square pixels
  • Assume QE=50 % flat from 300-600 nm

May 4-5, 2006 T.Schweizer, CTA meeting Berlin

some numbers
Some numbers
  • Case study: square pixels with 4 SiPM chips à 1 cm x 1 cm
    • Light concentration 3.25 (with microlensing foil)
    • Light concentration 5
  • Absolute maxim allowed dark rate for SiPM: 20% of NSB

 Assume 100-200 kHz/1mm2 for future SiPM

May 4-5, 2006 T.Schweizer, CTA meeting Berlin

data volume generated by telescope system
Data volume generated by telescope system
  • Assume 2.5 GHz FADC (capacitor array) sampling
  • Assume 50 samples per pixel à 16 Bits  100 Bytes
  • Assume trigger rate of 2 kHz (at 10 GeV)
  • Assume 3000 Pixels
  • Assume 20 Telescopes
  • Assume an average of 8h observation time
  • About 10.5 Petabytes per month !!
  • Even with modern computers in 10 years this amountwill be a serious problem

May 4-5, 2006 T.Schweizer, CTA meeting Berlin

data reduction
Data reduction
  • Necessity for online data reduction
  • Online signal extraction from FADC slices Amplitude, Arrival time, Pulse width of largest pulse3 floats (can be reduced)  12 Bytes
  • Zero suppression  Low level image cleaningassume reduction factor 20 (maybe more ?)
  • Reduced data rate: 65 Terrabytes per month

(Still a lot ! )

Comment: Data reduction (signal processing) maybe already inside camera

May 4-5, 2006 T.Schweizer, CTA meeting Berlin

readout ideas
Readout ideas
  • All the readout electronics inside the camera reduces the cost of the camera (maximum weight 2 tons)
  • No heavy cabeling, simplified construction
  • Data reduction (signal processing) already inside the camera

1 Gbit Ethernet ?

Switch

Modules of 100 pixels

100 channeldomino sampling

Signal processorto extract signalsand data reduction

Collect data from all modules & ultrafast data transfer to DAQ

May 4-5, 2006 T.Schweizer, CTA meeting Berlin

cost estimates
Cost estimates
  • The camera housing + mechanics + Cooling and temperaturestabilization + Light concentrators: 400 k€
  • Price for 4 SiPM chips (one pixel): ~ 300 € (Hamamatsu)
  • Price for readout (Cap. array + signal processing) per channel: ~ 300
  • Sum price/channel: ~600 €
  • Sum all pixels (2250): ~1.4 Mio €
  • Total: 1.8 Mio €
  • Maxim price for camera + readout: 2 Mio €
  • Price for telescope frame 2-3 Mio €
  • Price for one telescope: 4-5 Mio €
  • 70 Mio €/4-5 Mio €  14-17 telescopes

May 4-5, 2006 T.Schweizer, CTA meeting Berlin

timing
Timing
  • First light within 5-6 years ?
  • SiPM chips probably available within 2 years
  • Use standard mechanics/electronics as much as possible
  • Time plan
    • Camera development with SiPM: 4 years
    • Development time for mechanics 2-3 years
    • Production and installation of 16 telescopes: 2-3 years
  • All together: 5 years until first telescope installed ?

May 4-5, 2006 T.Schweizer, CTA meeting Berlin

ad