Specifications

PERFORMANCE-PREAMPLIFIER

INTEGRAL NONLINEARITY  <±0.02%, 0 to +10 V.

TEMPERATURE INSTABILITY <±0.005%/°C, 0 to 50°C.

OUTPUT RISE TIME <100 ns for test input or fast scintillator.

OUTPUT FALL TIME Time constant of 50 µs.

OUTPUT NOISE <50 µV rms with ORTEC main amplifier such as Model 672 and time constant of 1 µs.

CONVERSION GAIN Nominally 5 µV/eV with 2- by 2-inch NaI(Tl) crystal and PMT gain of 10⁶; the typical output for a 511-keV x ray with a 10-stage PMT gain of 10⁵ will be ~250 mV.

SATURATION LEVEL  +10 V into an open circuit; +5 V into 93-W load.

PERFORMANCE AND VOLTAGE DIVIDER

Resistor-divider connected to 10-stage PMT base. Total resistance 5.6 MW, resulting in bleeder current of 200 mA with typical high voltage of 1 kV. The distribution is linear to all stages with the focus adjustment on the grid.

CONTROL

FOCUS Single-turn locking potentiometer on panel for external adjustment of PMT grid potential.

INPUTS

POS HV SHV connector, AMP 51494-2, for distribution of positive high voltage to PMT base; +2000 V maximum.

TEST BNC connector, accepts pulses from an ORTEC pulse generator for testing and calibration.

SIGNAL Preamplifier input is connected internally to dynode 10.

POWER Captive 4-m (12-ft) power cable terminated in Amphenol 17-20090 connector accepts preamplifier operating power; compatible with all ORTEC main amplifiers and the Model 4002P Portable Power Supply.

PM SOCKET TRW 3B14. Fits JEDEC B14-38 PMT pin base (see Fig. 1).

OUTPUTS

PREAMP BNC connector, furnishes preamplifier positive output pulse to an ORTEC main shaping amplifier for linear energy analysis; Z_o = 93 W, dc-coupled.

ANODE BNC connector, furnishes negative anode output pulse for use either in timing or auxiliary energy analysis; Z_o = 1 kW, ac-coupled.

ELECTRICAL AND MECHANICAL

POWER REQUIRED For preamplifier, +24 V, 16 mA; -24 V, 16 mA; for PMT base, +2000 V maximum (use rated voltage for the tube that is installed).

WEIGHT
Net 0.65 kg (1.5 lb)
Shipping 1.3 kg (3.0 lb)

DIMENSIONS 5.6 cm (2.2 in.) diameter x 10.2 cm (4 in.) long plus 4 m (20 ft) captive power cable.

ACCESSORIES

A C-36-12 Cable is required for connecting to a high-voltage supply. A C-24-12 Cable is recommended for connecting the preamplifier output to the spectroscopy amplifier. For timing signals from the anode, use a C-25-12 Cable.

Fig. 1 JEDEC B14-38 PMT Pin Base, with Pin Assignments:

ORDERING INFORMATION