3
2. SPECIFICATIONS
2.1. PERFORMANCE
NOISE Increases with increasing input capacitance.
Typical performance values, based on silicon
equivalent of
,
= 3.6 eV at
J
= 2µs, are 1.9 keV at
0 pF; these degrade to 4.6 keV at 100 pF and to
35 keV at 1000 pF.
RISETIME Based on a +0.5 V signal through either
output into a 93
S
circuit and measured from 10%
to 90% of peak amplitude; 20 ns at 0 pF and 50 ns
at 100 pF.
SENSITIVITY Nominal, measured through either
output, 45 mV/MeV Si.
ENERGY RANGE 0 to 100 MeV Si.
ENERGY RATE 3 X 10
5
MeV/s.
DYNAMIC INPUT CAPACITANCE 10,000 pF.
INTEGRAL NONLINEARITY
#
0.05% for 0 to ±7 V
open circuit, or ±3.5 V terminated in 93
S
.
TEMPERATURE INSTABILITY
#
±100 ppm/°, 273
to 323 K (0 to 50°C).
DETECTOR BIAS ISOLATION ±3000 V.
OPEN LOOP GAIN
$
40,000.
2.2. INPUTS
INPUT Accepts input signal from a detector and
extends operating bias to the detector.
BIAS Accepts the bias voltage for the detector from
a bias supply.
TEST PULSE Accepts input voltage pulses from a
pulse generator for instrument and system check
and calibration; R
in
= 93
S
.
2.3. OUTPUTS
E AND T (for Energy and Timing) Two connectors
furnish identical signals through two output paths;
either or both outputs can be used as required, and
they are interchangeable; R
0
= 93
S
through each
connector and the output polarity is opposite from
the input pulse polarity (output pulse polarity is the
same as bias polarity).
2.4. CONNECTORS
INPUT and BIAS Type SHV.
TEST PULSE, E, and T Type BNC.
POWER CABLE 10-ft (3 m) captive power cable,
ORTEC 121-C1; longer lengths available from
ORTEC on special order.
2.5. ELECTRICAL AND MECHANICAL
POWER REQUIRED Furnished from NIM bin and
power supply through any ORTEC main amplifier,
or from an ORTEC 114 Preamplifier Power Supply;
built-in captive cable is compatible with either
source.
+24 V, 30 mA; -24 V, 10 mA; +12 V, 15 mA;
-12 V, 15 mA.
DIMENSIONS 1.5 x 2.4 x 4.5 in., plus 10-ft cable
(38 x 61 x 114 mm, plus 3 m cable).
3. INSTALLATION
3.1. CONNECTION TO DETECTOR
A direct connection with shielded cable should be
made between the detector and the Input SHV
connector on the preamplifier. The performance of
the 142IH Preamplifier, like that of all similar
instruments, is degraded as the capacity at the
input increases. Therefore it is important that the
length of coaxial cable used between the detector
and the preamplifier be kept at the minimum length
that is necessary. Also it is preferable to use 93
S
or
100
S
characteristic impedance cable rather than
75
S
or 50
S
cable because the capacity per foot is
less for the cable with the higher characteristic
impedance. Type RG-62/U cable is recommended;
this has a 93
S
impedance and a capacitance of
13.5 pF/ft (40.1 pF/m). An AMP 51426-2 connector
mates with the SHV connector on the 142I
Preamplifier.
Содержание 142IH
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