Koperek - more information about the pulse amplifier & amplitude discriminator

Introduction

Active Filter Amplifier & Pulse Height Window Discriminator Koperek-1 is designed in CAMAC standard ( double size ). It is oriented to mating with radiation detectors and is characterized by big peak resolution, good stability and wide range of gain setting. It accepts positive and negative pulses.
Thanks to the active filters using the output pulses have a quasi-gaussian shape. This guarantees optimal signal-to-noise ratio, and the Pole-Zero Cancellation circuit gives a big amplitude overload capacity.

This pulse amplifier properly works with charge preamplifiers, which output pulses decay time belongs to 50 .. 500 us range. The direct mating with some types of scintillation probes is also possible.

The built-in window discriminator is internally connected with amplifier output circuit.
It contains :

• the base line restorer ( disconnected while working with bipolar output pulses )
• low level and high level threshold discriminators
• peak detector

Basic technical data

• Input - LEMO female connector on the front panel.
  • DC or AC coupling jumpering inside the module
  • Positive or negative pulse polarity jumpering inside the module
  • Pulse decay time in 50 .. 500 us range to ensure pile-up rejecting
  • Input resistance 1k.
  • Maximum input signal corresponding to full ADC scale at minimum gain : 1V
• Gain - fine adjustable from 10 up to 1500 V/V.
  The gain is determined by switch with 6 settings : x20, x50, x100, x200, x500, x1000 and the 10-turn potentiometer with x0.5 to x1.5 multiplier range.
  • Gain tolerance 5%.
• Time shaping constans
  • 0.5 us
  • 1 us
  • 2 us with tolerance 20 %.
  Time constans are choosen by 3-position switch on the device rear plate.
• Integral nonlinearity of amplifier < 0.15% for full output range
• Noise voltage reffering to the amplifier input, with unipolar pulses, for gains >= 200 and time constats = 2us : <= 20uV
• Amplifier output - Lemo female connector on the front panel.
  • AC coupling
  • positive polarity or bipolar pulses ( selected by inside module jumper marked : OUTPUT ).
  • Pulse amplitude for linear operation : 10 V.
  • Max pulse amplitude : 15V.
  • Output impedance < 5 ohm
• Amplifier gain instability 24h : < 0.1%.
  
  
• Threshold levels from 50 mV up to 10 V which corresponds to discriminator multiturn potentiometers positions from 0.05 up to 10.00
• Discriminator outputs - complementary TTL-signals which appears, when pulse amplitude is situated in discriminator window
  • Pulse rise time : <= 16 ns
  • Pulse fall time : <= 30 ns
  • Pulse length : 350 ns +-20 %.
  • Output impedance : 50 ohm
• Discriminator Integral nonlinearity : <= 0.1%
• Dead time : 1us +- 0.2 us.
• Power supply consumed from CAMAC casette

  +24V	. . .	120 mA
  +6V	. . .	105 mA
  -6V	. . .	45 mA
  -24V	. . .	80 mA