570 Amplifier

Specifications

PERFORMANCE

Gain Range  Continuously adjustable from 1 to 1500.

Pulse Shape  Semi-Gaussian on all ranges with peaking time equal to 2.2t and pulse width at 0.1% level equal to 2.9 times the peaking time.

Integral Nonlinearity  For 2-µs shaping time, <±0.05%.

Noise  Typically <5 µV for unipolar output referred to the input, using 2-µs shaping and Coarse Gain ³100.

Temperature Instability
Gain  £±0.0075%/°C, 0 to 50°C.
DC Level  £±50 µV/°C, 0 to 50°C.

Bipolar Crossover Walk  £±3 ns at 0.5 µs for 50:1 dynamic range, including contribution of an ORTEC Model 552 Single-Channel Analyzer.

Overload Recovery  Recovers to within 2% of rated output from X300 overload in 2.5 nonoverloaded pulse widths using maximum gain for Unipolar Output.

Spectrum Broadening Typically <16% FWHM for a ⁶⁰Co 1.33 MeV gamma line at 85% of full scale for an incoming count rate of 1 to 75,000 counts/s (Unipolar Output, 2-µs shaping).

Spectrum Shift Peak position shifts typically <0.024% for a ⁶⁰Co 1.33-MeV gamma line at 85% of full scale measured from 1 to 75,000 counts/s (Unipolar Output, 2-µs shaping).

ELECTRICAL AND MECHANICAL

Power Required  +12 V, 60 mA; -12 V, 30 mA; +24 V, 80 mA; -24 V, 85 mA.

Weight
Net  1.5 kg (3.3 lb.)
Shipping  3.1 kg (7.0 lb.)

Dimensions  Standard single-width NIM module 3.43 x 22.13 cm (1.35 x 8.714 in.) per DOE/ER-0457T.

CONTROLS

FINE GAIN  10-turn precision potentiometer with graduated dial for continuously variable direct-reading gain factor of X0.5 to X1.5.

COARSE GAIN  6-position switch selects feedback resistors for gain factors of 20, 50, 100, 200, 500, and 1k. Jumper on the printed wiring board (PWB) selects X0.1 attenuation.

INPUT POLARITY  Locking toggle switch selects either Pos or Neg input pulse polarity.

SHAPING TIME  6-position switch selects time constants for active pulse-shaping filter network from 0.5, 1, 2, 3, 6, and 10 µs.

PZ ADJ  Screwdriver adjustable potentiometer to set the pole-zero cancellation to compensate input decay times from 40 µs to infinity.

BLR  3-position locking toggle switch selects the source of control for the gated baseline restorer discriminator threshold from:

Auto  The BLR threshold is automatically set to an optimum level, as a function of the signal noise, by an internal circuit.
PZ Adj The BLR threshold is determined by the threshold potentiometer. The BLR time constant is also greatly increased to facilitate pz adjustment; this position may give the lowest noise for count rates under 5000 counts/s and/or longer shaping times.
Threshold  The BLR threshold is manually set by the threshold potentiometer.

DC  Screwdriver adjustable potentiometer to set the Unipolar Output dc level; range ±100 mV.

INPUTS

Front-panel BNC connector accepts either positive or negative pulses with rise times of 10 to 650 ns and decay times of 40 µs to infinity, Z_in @ 1000 W dc-coupled; linear maximum 10 V; absolute maximum 20 V.

OUTPUTS

UNIPOLAR  Front-panel BNC connector with Z_o <1 W, short-circuited proof; prompt with full-scale linear range of 0 to +10 V; active filter shaped; dc-restored; dc-level adjustable to ±100 mV.

PREAMP POWER  Rear-panel standard ORTEC power connector. Amphenol 17-10090, mates with captive and noncaptive power cords on all ORTEC preamplifiers.

Busy Output  Rear-panel BNC connector with Z_o <10 W provides a +5 V logic pulse for the duration that the input pulse exceeds the baseline restorer discriminator.

ORDERING INFORMATION