142AH Preamplifier

Specifications

PERFORMANCE

Performance specifications are for Energy output unless stated otherwise.

NOISE (see Fig. 2)

INTEGRAL NONLINEARITY  <±0.05% for 0 to ±7 V open circuit, or ±3.5 V terminated in 93 W.

TEMPERATURE INSTABILITY  <±50 ppm/°C from 0 to 50°C.

OPEN LOOP GAIN  >40,000.

CHARGE SENSITIVITY (Si equivalent)   Nominally 45 mV/MeV.

RISE TIME (Fig. 3)   <5 ns at 0 pF; <12 ns at 100 pF; with a 0 to +0.5-V pulse at the ENERGY output and a 93-W load.

DECAY TIME  ~500 µs.

RECOMMENDED INPUT CAPACITY RANGE   0 to 100 pF.

PERMISSIBLE OUTPUT CABLE LENGTH  Limited only by cable losses (recommended cable: ENERGY output, RG-71A/U or RG-62A/U; TIMING output, RG-58).

E²CRP  Maximum energy-squared count rate product: 1.5 x 10⁷ MeV²/s.

DETECTOR BIAS VOLTAGE  ±5000 V.

OUTPUT LEVELS AND LOADING  All specifications are stated for open-circuit output and remain unchanged for 93-W termination or cable loading, except terminted output levels are half the open-circuit values. Saturated output level, ±10 V; integral nonlinearity specified to ±7 V.

INPUTS

INPUT  Accepts positive or negative charge input from any type of detector (normally from a semiconductor detector); SHV connector.

BIAS  Accepts detector bias from bias supply and applies it to the detector through a filter network via the INPUT connector; maximum ±5000 V; SHV connector or ORTEC C-38.

TEST  Input for pulse generator to test and calibrate the system; BNC connector.

POWER  Input power through 3-m (10-ft) captive power cable from any ORTEC main amplifier or from an ORTEC Model 4002P Portable Power Supply.

OUTPUTS

ENERGY  Positive or negative linear tail pulse for energy measurement; BNC connector.

TIMING  Negative or positive linear fast clipped pulse for timing. Output generated by using an inverting transformer which differentiates the energy output. Rise time approximately equal to the rise time of the energy output (Fig. 3). BNC connector.

ELECTRICAL AND MECHANICAL

POWER REQUIRED  +24 V, 30 mA; -24 V, 10 mA; +12 V, 15 mA; -12 V, 15 mA.

WEIGHT
Net  0.45 kg (1 lb).
Shipping  1.3 kg (3 lb).

DIMENSIONS  4.45 x 10.16 x 13.21 cm (1.75 x 4.0 x 5.2 in.).

Fig. 1. Typical time resolution vs. energy for 90 and 27 pF detectors with ORTEC standard electronics.

Fig. 2.  Noise as a function of input capacitance, measured with an ORTEC Model 572 Amplifier and 2-µs time constant.

Fig. 3.  Typical rise time as a function of input capacitance with rise time compensation optimized at each data point. (Values given are for a +0.5 V signal into 93 W from the Energy channel.)

ORDERING INFORMATION