Shaping amplifiers are often used following the charge sensitive preamplifier stage and perform three functions: First, they provide an output pulse having a faster baseline restoration than the charge sensitive preamplifier output pulse. This is especially important at high count rates, where pulses from consecutive events can ‘pile up’. Secondly, shaping amplifiers filter some of the noise from the preamplifier output signal. Finally, shaping amplifiers can also be used to provide extra gain to the signal, which may be very small (sub mV) at the preamplifier output.

Cremat offers the CR-200 series of shaping amplifiers. They are available in seven different shaping times: 100 ns, 250 ns, 500 ns, 1 ms, 2 ms, 4 ms, and 8 ms. Each has a fixed gain of 10. To achieve greater gains, a broadband amplification stage should be added between the charge sensitive preamplifier and the shaping amplifier. Cremat offers an evaluation board for the CR-200 series amplifiers, which contains such a broadband amplifier. The combination of a CR-200 series amplifier with the CR-160 evaluation board creates a low noise shaping amplifier module complete with BNC connectors, variable gain (0 to 1000) and reversible polarity.

Use with the CR-160

The CR-200 series of shaping amplifiers can be easily tested using the CR-160 evaluation board.