(a)Basic proportional counter Track of X ray photo- electron Drifting ionization electrons Signal Expanded vicw Multiplication Anode X ray Thin beryllium +1500V entrance window Amp Anoile Argon gas Ground (b)Position sensitive proportional counter L Signal I X ray Signal 2 Amp Amp2 Resistive quartz anode Argon gas 6/4/2022 m Ground -150V
6/4/2022
Photoelectric Absorption in Silicon Wavelength (A) 100 0 1000.00 100.00 Depth of active 10.00 region in typical X-ray CCD 1.00 0.10 Best X-ray sensitivity 0.01 0.1 1.0 10.0 Energy(keV) 6/4/2022
6/4/2022
CCD ACIS FLIGHT FOCAL PLANE 获得光子 10 ACIS-I X 12 时间 SO SI S2 S3 S4 S5 位置 ACIS-S 能量 Top E/dE10-50 S-Image Region Pixel(L,)乙g Bottom Frame Store 6/4/2022
CCD 获得光子 时间 位置 能量 E/dE~10-50 6/4/2022
CCD X-ray Spectroscopy:The Basic Idea Photoelectric interaction of a single X-ray photon with a Si atom produces“free”electrons: N。=Ex/w(w≈3.7eVle) o2=F×N.(F≈0.l2;not a Poisson process) Spectral resolution depends on CCD readout noise and physics of secondary ionization: FWHM(eV)-2.35x wxa2+d CCD characteristics that maximize spectral resolution: Good charge collection and transfer efficiencies at very low signal levels Low readout and dark-current noise (low operating temperature) High readout rate (requires tradeoff vs.noise) 6/4/2022
6/4/2022
140 CCD X-ray Energy Resolution 120 需 WHM) 100 80 noise-free detector 4 e RMS readout noise 60 8 e RMS readout noise 40 ASCA SIS (1993):4e-RMS 20 Chandra ACIS (1999):2 e RMS 0 0 1000 2000 3000 4000 5000 6000 7000 8000 Energy (ev) 6/4/2022
6/4/2022