Functionally, the Model CSA4 provides in a single width NIM module an exceptional spectroscopy amplifier. The amplifier’s excellent stability, ultra low noise, broad gain range and wide choice of shaping time constants makes it ideally suited for applications involving Germanium, Silicon, Scintillation, Gas Proportional and Surface Barrier detectors.
FCT near-Gaussian filter shaping has been refined in the Model CSA4 for improved pulse symmetry, minimum sensitivity of output amplitude to variations in detector rise time, and maximum signal to noise ratio. For a given shaping time constant, the improved pulse symmetry minimizes the pulse dwell time by tucking in the trailing skirt of the unipolar pulse shape. This allows a faster return to the baseline. The result is superior energy resolution, count rate and throughput performance. Unipolar shaping is achieved with one differentiator and two active filter integrators. The differentiator is placed early in the amplifier to insure good overload recovery. The integrators are placed late to minimize noise contribution from the gain stages. Functionally, the Model CSA4 provides in a single width NIM module a preamplifier and a shaping amplifier with four shaping times simultaneously (selectable in the range from 100ns to 8μs: four values out of seven can be ordered : 100ns, 250ns, 500ns, 1μs, 2μs, 4μs, 8μs). A power connector (D-Sub 9 female) is also available at the front panel for the power supply of external preamplifiers. A front panel adjustable pole zero can be user trimmed to match the preamp fall time constant and minimize undershoot following the first differentiator for improved overload and count rate performance.
This section is not intended to serve as a complete list of applications. It is intended to identify some of the important features, and to indicate areas where they might be applied.
The Model CSA4 Spectroscopy Amplifier with its selection of shaping time constants allows it to be used in surface barrier, proportional counter, NaI ang Ge(Li) detector applications. The choice of shapings also allows the best possible performance by tailoring the system for the conflicting requirements of optimum signal to noise ratio and high count rate performance. The excellent stability and low noise contribution enhances the use of this amplifier in most applications.