x-ray data acquisition systems for airport security j m homer electron tubes ltd
TRANSCRIPT
X-ray data acquisition systems for Airport Security
J M Homer Electron Tubes Ltd
Electron Tubes Ltd
Specialises in X-ray and light detection systems UK based company Products
X-ray data acquisition systems Light detection modules Photomultipliers
Customers Security systems Instrumentation NDT systems Scientific research (HE Physics and Space)
Carry-on baggage scanner
Checked baggage scanner
Large baggage or container scanner
Airport security applications
Carry-on baggage scanner
Linescan system
Checked baggage scanner
CT system
Large baggage or container scanner
Multi-view linescan system
System types
Personal X-ray scanning
Compton backscatterusing photomultipliers
Material Thickness
mm
Energy Range
mm
Signal output Signal decay time
Silicon 0.3 5 – 25keV Highest signal, direct conversion
1µs
Gadox (Tb) 140gm/cm2 20 – 100keV Similar to CsI 2 – 3ms
CsI (Tl) 4.5mm 40 – 160keV Best light output
2 components, long decay tail
CdWO4 2.5mm –
30mm
150keV – 9Mev 25% of CsI 20µs
X-ray detectors
X-ray linescan system
Single energy and dual energy detectors
X-ray CT system
Requirements of data acquisition system
Large number of channels, 2000 to 20000
Sub-millisecond scan time
Wide dynamic range
Digital output
Low noise
Low cost
XDAS system
charge integrating method
simultaneous data acquisition and read-out
on board sub-sampling and data summation
links to PC via USB2 or PCI-7300A data I/O card
s/w controllable via RS485 interface
system read-out rate 5MB/s
Single Channel of ASIC
inputfrom
detector analogueoutput
multiplexer
sample & hold2 x 2 line
stores
2 or10 pF
XDAS module block diagram
XDAS system block diagram
XDAS V1X system
One digital board drives 20 detector head boards with 2560 channels
Multiple digital boards allow up to 30000 channels
System read-out rate up to 20MHz
Same capability as original XDAS system
Lower cost
128channeldetector
array
128channelASIC
signal processing board
XDAS-V1X detector head board
reset
usersettings
non-volatileRAM
central processingmodule (FPGA)
controlinterface(RS 485)
A to Dconverter
analoguemultiplexer
imagedatastore
20analogueinputchannels
detectorhead boards
computerinterface
(differential)
localinterface
localinterface(logic)
control
data
data
control
local control
sync controls
XDAS-V1X signal processing boardblock diagram
detectorhead
detectorhead
localbus
localbus
detectorhead
Power
I/O
0V
RS485
signalprocessing
5 MB/s8 Bit
64 channel bank A 64 channel bank A 64 channel bank A
64 channel bank B 64 channel bank B 64 channel bank B
XDAS-V1X system block diagram
XDM System
modular system of any length 6mm detector pitch suitable for use with high energy applications using Linacs high charge capacity (1000pC) 20-bit output 1 bit of noise high speed serial link to CPU systems designed to order
summary
modular X-ray data acquisition systems designed for use with linescan and CT X-ray systems
large number of channels fast low noise low cost per channel
digital output can be configured to meet specific requirements
solutions in light detection