Amplifier baseline shift

Adjustable gain amplifier affording baseline shifting. 

Alternating-current amplifiers generally do not perform well at low frequencies (< 10 Hz) and exhibit signal phase shift or signal differentiation. High-frequency response must be selected so that risetime is not compromised for the signals being processed. On the other hand, ac amplifiers provide stable operation, are relatively free from baseline drift, and require much less calibration than dc amplifiers. 

Coincidence and Dead-time Losses in y-Spectrometry. The influence of electronic effects at high-count rates on the performance of Ge(Li) detectors is considerable. The resolution of a detector can be degraded by effects within the amplification system, but these can be minimized by (i) the use of pole-zero cancellation, to prevent the pulse-height error caused by the tail of a preceding pulse and (n) baseline (or D.C.) restoration facilities to prevent similar errors caused by shifts in the apparent pulse baselines. The latter are a result of capacitative effects between the various stages of the overall amplifier, biased amplifier, and multi-channel analyser system. These effects can degrade the resolution of the detector but should not change the y-ray peak area. 

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