Kromek GR1-A, GR1 User Manual

Kromek GR1-A and GR1

Kromek GR1 User Guide

The GR1 is intended to be used in conjunction with the
K-Spect and MultiSpect Analysis software running on a
Windows-based (XP/Vista/7) personal computer.

The GR1 connects to the USB port
of the computer. It is powered via
the USB connection so no external
power supply is required.

Inside the GR1, signals from the
CZT detector are processed and
digitized, and the digitized pulse
height data is transferred to the
computer via the USB.

The K-Spect software receives
the data and performs the spectrum acquisition,
display, analysis and storage functions. The GR1 and
K-Spect software together form a complete gamma-ray
spectroscopy system.

K-Spect can be downloaded by visiting www.kromek.com;
click on the downloads tab and follow the on-screen
instructions.

K-Spect Software Installation

1. Installing K-Spect software

n Open the “K-Spect Installer” zip le.

n Double-click or run the Setup.exe le.

n Follow the on-screen instructions.

2. Run K-Spect

Double click the K-Spect desktop shortcut or select
the K-Spect program under the Windows Start menu.
The K-Spect window will appear with a blank spectrum

displayed.

GR1 Operation

Connect the GR1 to the computer’s
USB port via an appropriate USB
cable. A cable is supplied with the
unit, but other standard USB cable
with a mini-B 5-pin connector will
work.

Within a few seconds, the K-Spect
software will recognize the GR1 and indicate that the
device is connected with a message in the status bar at
the bottom of the K-Spect window.

After the GR1 is connected for about 1 minute, valid
signals are generated and spectra can be acquired.
However, for best performance, the unit should be allowed
to stabilized for about 5 minutes before use.

Click the “Acquire” button to start acquiring a spectrum.
The gain of the system is xed so
that the full spectrum is always
acquired, with full scale (4096
channels) equals to slightly
above 3 MeV. The LLD (lower
level discriminator) can be set by
selecting “Setup” and then “Set
LLD”.

The cursor will change color to red
and a “LLD” label will appear. Move the LLD as desired to
cut out low-energy part of the spectrum or the noise peak.
More details on the operation of K-Spect can be found
under the ‘Help’ menu.

GR1

Gamma Ray

Spectrometer

MAL-OPS-0877 Rev 4

Kromek GR1-A User Guide

Kromek Ltd NETPark Thomas Wright Way Sedgefield County Durham TS21 3FD UK

T: [phone] E: [e-mail] W: www.kromek.com

The Advanced GR1 (GR1-A) is a USB-powered gamma
spectrometer employing the same 1x1x1cm3 co-planar
grid CZT detector and electronics
as used in the GR1 but having
auxiliary input/outputs which
greatly increase its operational
exibility.

In addition to the mini USB
connector used to connect the
device to a Windows based
personal computer running
the K-Spect or MultiSpect Analysis spectroscopy
application, three MCX connectors are provided on the
rear panel of the unit as shown below.

These connectors provide the
following functions:

Energy output: Shaped and
buffered detector output pulses
with amplitude proportional to
energy suitable as the input to an
external MCA.

Timing output: A logic pulse
triggered by each detected event
and coincident with each output
pulse.

Gate input: Used to suppress
pulse height output via the
USB interface to K-Spect for
anticoincidence. Energy and
timing outputs are unaffected.

Details of the corresponding three
signals are given below.

Software

MultiSpect Analysis is included
on a ash disk and can be
downloaded by visiting:
www.kromek.com click on the
downloads tab and follow the on­screen instructions. Please check for updates.

Energy
Output

Rise time 3 µs

Decay time 10 µs

Output impedance < 150 Ω

Timing
Output

Shape TTL compatible rectangular pulse

Amplitude 4.5 – 5.0 V

Duration 8 µs

Output impedance < 150 Ω

Timing Resolution < 100 ns

Gate
Input

Threshold 3 V

Maximum input voltage 5 V

Input impedance 5 kΩ

Timing

Input must be above threshold from at least

0.5µs before the energy signal maximum to
at least 2µs after it.

Note: In the absence of any connection the gate input is held low and all pulses
are processed normally.

Specication (GR1 and GR1-A)

Detector 10mm x 10mm x 10mm CZT detector

Energy range 30 keV to 3.0 MeV

Energy resolution <2.5% FWHM @ 662 keV

Electronic noise <10 keV FWHM

Maximum throughput 30,000 counts/s

Number of channels 4096 (12 bit)

Differential non-linearity < ± 1%

Power consumption 250 mW

Dimensions 25mm x 25mm x 63mm

Weight 60 gram

Temperature 0 - 40oC

Additional specication for GR1-A only

Gate

Energy

Timing

USB