542 Linear Gate and Stretcher

 Specifications

PERFORMANCE

NOISE CONTRIBUTION <20 µV rms, referred to input.

GATE FEEDTHROUGH <0.005% of signal amplitude with gate closed.

GATE PEDESTAL Essentially zero, factory-calibrated.

STRETCHER DROOP Typically <0.1 mV/ µs/V output.

PILEUP REJECTION After the input pulse has reached its peak, subsequent inputs are rejected until both the output pulse has terminated and the input has recovered to the baseline.

GAIN Unity (nominal).

INTEGRAL NONLINEARITY £±0.2% for pulse rise time >100 ns and pulse width >400 ns.

TEMPERATURE INSTABILITY Gain shift <±0.01%/°C, 0 to 50°C for V_o = 5 V.

COUNTING RATE dc-coupled throughout when DC Couple input is selected. The centroid of a pulser spectrum at 85% of full scale will shift <0.1% when modulated by 5 x 10⁴ counts/s of random signals from ¹³⁷Cs source-detector combination with photopeak at 70% of full scale (DC Couple mode and amplifier shaping time t = 1 µs).

CONTROLS

NPUT
Slide Switch Front-panel 3-position slide switch selects input circuit desired: BLR High, BLR Low, or DC Couple.
Disc Level Front-panel screwdriver potentiometer adjusts sensitivity level for input discriminator; range +0.1 to +1 V; discriminator remains triggered while input level exceeds adjusted sensitivity.

OUTPUT
Delay Front-panel screwdriver potentiometer; adjusts delay period from peak detect to the start of the output pulse; typical range 0.5 to 5 µs. (Delay ranges up to 50 µs available on special request.)
Width Front-panel screwdriver potentiometer adjusts width of the output pulse; typical range 0.5 to 5 µs.

NORMAL/GATED Front-panel locking toggle switch selects exclusion (Normal) or inclusion (Gated) of external gating function.

GATE PERIOD Front-panel screwdriver potentiometer adjusts duration of gating control from leading edge of Gate Input pulse; range 0.5 to 5 µs, includes test point for monitoring adjusted gate period.

COINC/ANTICOINC Front-panel locking toggle switch selects effective mode for Input Gate function.OUTPUT DC ADJ Front-panel screwdriver potentiometer permits adjustment of output dc level between ±1.5 V.

EXT/INT Rear-panel locking toggle switch selects between (External) strobe operation or (Internal) normal/gated operation.

INPUTS

GATE Front-panel BNC connector for optional external control for switch-selectable coincidence or anticoincidence mode triggering. NIM-standard slow logic pulse triggers selected gate function at +3 V (100 ns minimum width), protected to ±25 V.

LINEAR Front-panel BNC connector.
Polarity Positive unipolar or bipolar with positive portion leading.
Amplitude +0.1 to +10 V linear; ±12 V maximum 
Rise Time 100 ns to 10 µs.
Impedance ~1000 W.

EXT STROBE Rear-panel BNC connector for optional external control of the output pulse timing. NIM-standard slow positive logic pulse triggers the strobe function at +3 V (100 ns minimum width), protected to ±25 V.

OUTPUTS

OUTPUT Front-panel BNC connector furnishes linear positive output pulses through Z_o < 1 W; rise time 300 ns; includes test point.

Polarity Positive.

Amplitude +0.1 to +10 V, equal to peak amplitude of the accepted linear input pulse.

Delay Adjusted by front-panel control; range 0.5 to 5 µs after peak detect.

Width Adjusted by front-panel control; range 0.5 to 5 µs.

Impedance <1 W on front panel.

DCOffset Adjust ±1.5 V.

93 W OUTPUT Rear-panel BNC connector furnishes the same linear signals as the front-panel output, except the output impedance is 93 W.

BUSY Rear-panel BNC connector furnishes +5 V nominal through Z_o < 10 W through all periods when input pulses cannot be accepted; may be used to control external equipment or for monitoring internally created dead time.

Busy +5 V nominal, linear pulse cannot be accepted.

Not Busy 0 V nominal, linear pulse can be accepted.

ELECTRICAL AND MECHANICAL

POWER REQUIRED The Model 542 derives its power from a standard NIM bin/power supply. The power required is +24 V, 83 mA; –24 V, 80 mA; +12 V, 130 mA; –12 V, 30 mA.

WEIGHT
Net 0.9 kg (2.0 lb).
Shipping 1.9 kg (4.0 lb).

DIMENSIONS NIM-standard single-width module 3.43 X 22.13 cm (1.35 X 8.714 in.) per DOE/ER-0457T.

ORDERING INFORMATION