Digital Pulse Processor, MCA andPower Supply for HPGe

PX5-HPGeFeatures• Includes digital pulse shaping amplifier, MCA,and power supplies• Compatible with standard HPGe detectors• Trapezoidal shaping with wide range of peaking times to optimize performance• High count rate capability with excellent
baseline stability, throughput, and pile-up
rejection• Up to 8k output MCA channels• Oscilloscope mode - DAC output for pulse
monitoring and adjustment

1.0E+02
1.0E+01

Communications• Interfaces: RS-232, USB, Ethernet, I C, auxiliary• Software for PC data acquisition and control• Software Developer’s Kit included (SDK)Power• High voltage bias adjustable ±5kV• Preamp power ±12V, ±24V
• Operates from +5 V DC supply (AC poweradapter included)

UO3
Lantern Mantle
Background

1.0E+00

CPS

2

1.0E-01
1.0E-02
1.0E-03
1.0E-04

0500

1000

1500

Energy (keV)

2000

Spectra of low intensity material obtained with HPGe detector and a
PX5-HPGe signal processor.

Overview
The PX5-HPGe is a modified version of Amptek’s PX5 signal processor and power supply. A custom
power supply board is installed in a standard PX5, providing the higher bias voltages needed by an HPGe
detector along with the higher preamp power voltages and currents required by most HPGe preamplifiers.
A custom front panel is also installed, which mates with industry-standard connectors on HPGe detector/
preamp modules. The signal processing circuitry is unchanged from a standard PX5.
Amptek’s PX5-HPGe combines a high performance digital pulse processor with the power supplies
needed for standard cryogenic HPGe detectors. It replaces a conventional shaping amplifier and multichannel analyzer, providing very high performance signal processing in a single compact, low power
module, replacing multiple bulky NIM modules in a traditional solution. The digital signal processing
provides several advantages over analog solutions: lower electronic noise, reduced ballistic deficit, higher
throughput, enhanced stability, and more configuration options to better optimize the system for particular applications. It supports USB, Ethernet, and RS232 communications protocols and has numerous
auxiliary I/O options (MCS mode, 8 SCAs, a gate input for Compton suppression, etc).
The HPGe PWR board provides a bias voltage up to +/-5kV, with a hardware plug to change polarity.
It includes an HV inhibit line (to turn off the HV supply if the detector is too warm). The HPGe PWR
board also provides low voltages of +/-12VDC and +/-24VDC, at 80 and 40 mA respectively, using astandard 9 pin preamp power connector.

Amptek, Inc.

Tele: +1 781-275-2242

2500

14 DeAngelo Drive, Bedford MA 01730

Fax: +1 781-275-3470 sales@amptek.com

www.amptek.com

Preliminary Specifications
Please refer to the PX5 specification sheet for the pulse processing performance, MCA performance, and other key specifications. This sheet only lists those specifications which are changed for the PX5-HPGe.

HV BiasPreamp Power
100 to 5,000 VDC+/- 12 VDC±10%, 80 mA (max)Polarity+/-, selected by plug+/- 24 VDC±10%, 40 mA (max)Current

20 µA

Power

HV Inhibit

Active High or Low, set by internal
switch

+5 V+5 VDC at 220 mA (1.1 W) typicalInput Range+4.5 to +5.5 VDC

Voltage

5.0E+04CoCs133Ba601374.0E+04

Na

Normalized Counts

22

3.0E+04

2.0E+04

1.0E+04

0.0E+00

0200

400

600

800

Energy (keV)

1000

1200

1400

1600

Spectra of laboratory radioisotopes obtained with an HPGe detector and a PX5-HPGe signal processor.

Block Diagram
Cryostat

PX5Preamp

FPGARFCF

PREAMP OUTAMP IN

ADC

Fast Channel

Pulse
Selection

Digital Pulse
Shaping

MCA
Logic

MCA
MemoryUSB

Microcontroller

OUTPUT

50 us tail pulse
100 (500) mV/
MeV (10V max)PC

Analog Prefilter

Ethernet
Controller

Ethernet

AUX-1
HV BIAS

HPGe PWR+/- 3 to 5 kV
Adjustable<10 nAAux I/OControlDigital

HVPS
Temp
Sensor

DAC

SCAs

AUX-2

Oscilloscope(Optional)

AUX-3

HV INHIBIT

Polarity plug
+24 VDC-24 VDC+12 VDC-12 VDC

LVPS

5 VDC

PowerInput

Amptek, Inc.

110 VAC(isolated)

GND

LVPS

Tele: +1 781-275-2242

AC/DC

14 DeAngelo Drive, Bedford MA 01730

Fax: +1 781-275-3470 sales@amptek.com

www.amptek.com