1. Some random thoughts on dish antenna experiments
Marek Kowalski
Universität Bonn

2. 10-6 Hz
10-8 Hz

4. Sensitivity With increasing A and constant angular reslution,
Horns et al., JCAP 2013
With increasing A and constant angular reslution,
the dimensions of the image, as well as the 
detector noise increases linearly.

5. Example for a 20 cm f/4 dish @ 500nm
PSF width (diffraction limited): 1.2 x f/8 x λ = 5 μm
Focus spot size: 4 x (f/8)2 x λ = 128 μm
Alligment light source at center of dish
Allignement should not to be a problem
Possible sensors: CCD, TE sensor or PMT?

6. Wide Field Camera 3 on the Hubble Space Telescope
High quality, substrate-removed 1.7 μm HgCdTe arrays delivered to Goddard Space Flight Center
Dark current (145K) = 0.02 e-/pix/sec
Readout noise = 25 e- (single CDS)

7. Beletic

8. Photomultipliers Disadvantages: Limited wavelength range Advantages:
Large size!
Noise ~1 Hz per cm2 area (cooled to <-10oC)
Possible variation: Light concentration through wavelength shifting lightguides, readout by small PMTs. Noise reduction by factor ~100 possible (development done in Bonn)
Similar technique as in solar
luminiscent concentration

9. Photomultipliers Disadvantages: Limited wavelength range Advantages:
Large size!
Noise ~1 Hz per cm2 area (cooled to <-10oC)

10. Transition Edge sensors
Pros:
Single photon sensitivity
Limited energy information per photon
Low noise (10-3 Hz or lower?)
Disadvantages
Limited Size
Complicated operation

11. Figure of merit Example 1: Example 2: Adish = 0.2 m2 (0.5 m diam)
Adetector = 200 μm2
Ndark = 500 Hz (using CCD)
T=107 s
FoM =
Example 2:
Adish = 7 m2 (3 m diameter)
Adetector = 1 cm2 (~1 arcmin FoV)
Ndark = 1 Hz (using PMT)
T=107 s
FoM =