60 likes | 190 Views
TES key development Issues. Energy resolution Aim for 1 eV type resolution for E < 1 keV Field of view Increase of pixel size to typically 5/3 – 5/2 arc sec ≡ 416 - 625 μ m (settle on 500 μ m) Increase of pixels above 32 x 32 elements (wait for array and read-out developments going-on)
E N D
TES key development Issues • Energy resolution • Aim for 1 eV type resolution for E < 1 keV • Field of view • Increase of pixel size to typically 5/3 – 5/2 arc sec ≡ 416 - 625 μm (settle on 500 μm) • Increase of pixels above 32 x 32 elements (wait for array and read-out developments going-on) • Count rate ability • TES limited to approximately 0.1 ms speed XEUS Cryogenic Instrument 26 - 27 October 2004
Energy resolution limit is given by: TES key development Issues with ESAT given by Measured value of EFWHM = 4 eV for C = 0.5pJ/K, α = 70, and T = 100 mK is a factor 3 worse than theory. This is partially due to excess noise and partially due to non-optimum data analysis algorithm. A better data-analysis algorithm should result in 2.5 – 3 eV. Saturation energy equals ≈ 10 keV for r = 0.1 Reduction of the saturation energy to 2.5 keV, C ≈ 1.25 10-13 J/K, would therefore result in an energy resolution improvement by a factor 2.0 Present schemes would than result in ≈ 2 eV energy resolution, while with better data analysis about 1.3 eV is expected. Better understanding and reduction of the excess noise might result in a limit of 0.6 eV FWHM XEUS Cryogenic Instrument 26 - 27 October 2004
Energy resolution limit vs pixel size • We can manufacture standard type pixels with a heat capacity C= 0.125 pJ/K and up to 250 x 250 μm2 • 0.05 pJ/K for TiAu TES • 0.06 pJ/K for Cu/Sn and 0.08 pJ/K for Cu/Bi absorber • Larger pixels will require different designs. Scaling to .5 x .5 mm pixels seems quite well feasible by • Reduction of the fill factor TES/Multiple small TES in parallel • Non-continuous Cu-layer beneath Bi/Sn absorber • Pixels in access of 0.5 x 0.5 mm can most probably not be produced with a saturation at 2.5 keV and its corresponding energy resolution TES key development Issues XEUS Cryogenic Instrument 26 - 27 October 2004
single pixel optimization • single pixel production by micro-electronics techniques • Array production development • Read-out and multiplexing • SQUID development and optimization • How we can use expertise build up for TES development for support of the magnetic sensor line? Magnetic sensor key development Issues XEUS Cryogenic Instrument 26 - 27 October 2004
Prove of good energy resolution for large DROID’s • Arraying of DROID’s • Array read-out electronics STJ sensor key development Issues XEUS Cryogenic Instrument 26 - 27 October 2004
X-ray entrance filters and UV – IR rejection filters • Cryogenics Common key development Issues XEUS Cryogenic Instrument 26 - 27 October 2004