X-Ray Optics and Instrumentation / 2010 / Article / Tab 5

Review Article

Kirkpatrick-Baez (KB) and Lobster Eye (LE) Optics for Astronomical and Laboratory Applications

Table 5

Multifoil versus MCP approach to the Lobster ASM.

PropertyMCPMulti-foil

Surface microroughness 1 0 - 2 0 Å [54, 55, 90] + 3 - 1 0 Å [57, 102]
Metal coatingMore complicated, getting better + Simple, standard
MultilayersVery difficult + Simple, standard [22]
Gain1 (1 keV)10–100 (30–40 derived from [54]) + 100–1000 (~2500 simulation ~1000 reality)
Gain2 (8 keV)Not documented + 10–100 ( 3 0 0 - 4 0 0 [21], point-to-point focus)
Optics Weight3~0.1 kg [54] + ~1.0 kg
Optics dimensions4 7 0 . 0 × 7 0 . 0 × 0 . 3  mm [54] + 7 8 × 7 8 × 2 3  mm
FOVUnlimited in principle + Wide but limited
Energy range<3 keV [54] + <10 keV5
ASM module FOV6 2 0 × 2 0  deg [54] + 6 × 6  deg
Daily limiting flux [ 1 0 1 3 e r g s 1 c m 2 ]~20 [54] + ~5–107
Angular resolution~4 arcmin + + ~4 arcmin
Detector shapeCurved [54] + Planar

1Defined as a ratio of photons gathered inside the FWHM with and without optics.
2Defined as a ratio of photons gathered inside the FWHM with and without optics.
3 6 × 6  deg FOV, 𝑓 = 3 7 . 5  cm, both approaches scaled to fit these criteria.
4 6 × 6  deg FOV, 𝑓 = 3 7 . 5  cm, both approaches scaled to fit these criteria.
5 Au coated, microroughness 𝜎 1 0 Å.
6 The rating of this property is disputatious: larger FOV results in smaller number of modules to build and test, on the other hand, if anything goes wrong, larger part of the sky will be uncovered and higher costs for insitu repair is demanded.
7 Depends on the PSF blurring by distortions, backgroung estimates….