AdvaPIX TPX3

Advapix

Advacam’s AdvaPIX TPX3 camera is designed with special emphasis on performance and versatility, which is often required in scientific research world. The camera module contains CERN’s latest Timepix3 device with ultra-fast sparse data readout to acquire up to 40 million hits/ second. The module uses USB 3.0 communication channel assuring quick read-out of the system.

Description

The Advacam’s AdvaPIX TPX3 can be used in a variety of applications, such as energy resolved radiography (X-rays, neutrons, ions), time-of-flight imaging, multilayer Compton camera, particle tracking, and many others. The sensors can be modified for neutron imaging by depositing converter layer (6LiF). Recording individual hits together along with advanced data processing allows increased spatial resolution to units on a micron or even sub-micrometric level (for ions). The camera’s modules can be used in different configurations: telescope of several layers for better particle tracking and/or side-by-side for larger area coverage.

Compared to the older Timepix chip, the Timepix3 detector offers 6x better time resolution, 2x better energy resolution, 2x lower minimum energy threshold,  10x faster data transfer and zero dead time. A separate USB 3.0 channel for each module assures fast read-out of the whole modular system. The sensor type and thickness is of customer’s choice.

  • Sensor Material: Si or CdTe
  • Sensor Thickness: 100 μm, 300 μm and 500 μm for Si; 1 mm for CdTe
  • Sensitive Area: 14 mm x 14 mm
  • Time Resolution: 1.6 ns
  • Readout Speed: 40 Million hits/s
  • Number of Pixels: 256 x 256
  • Pixel Pitch: 55 μm
  • Energy Resolution: 1 keV
  • Min Detectable Energy: 3 keV for X-rays
  • Readout Chip: Timepix3
  • Pixel Mode of Operation: Time-over-Threshold, Time-of -Arrival
  • Connectivity: USB 3.0 (Super-Speed)
  • Weight: 503 g
  • Dimensions: 125 mm x 79 mm x 25.5 mm
  • Software: Pixet Pro

Typical Applications:

  • Spectral X-ray imaging: X-ray fluorescence imaging, X-ray radiography (low flux)
  • Energy dispersive XRD, SAXS or WAXS: The monochromatic X-ray source is NOT needed! Even high energy for thick samples is possible (e.g. 100 keV)
  • Spectral gamma ray imaging: Scintigraphy or SPECT, radiography with isotopes
  • Radiation monitor: Particle type sorting, spectroscopy, directional sensitivity
  • Gamma camera: Special shielded box and collimators
  • Compton camera: Special software module available for image reconstruction

Documents


Device parameters

Operating conditions

Symbol Parameter Value Units Comment
TA Ambient Temperature Range 0-50 °C
Φ Humidity <80 % Not condensing
Altitude* <2000 m Above sea level
IP IP rating IP40 With cover
*for use in vacuum chamber, operate only with air pressure lower than 10-3Pa Location: Intended for indoor use, dust free.

Electrical Specification

TA = 25°C, USB voltage VCC = 4.8V
Symbol Parameter Min Typ Max Units Comment
VCC Supply Voltage 4.0 5.0 5.5 V
ICC Supply Current
ICC1 Chip active 800 1500 mA
P1 Power Dissipation 7.5 W
I/O Conn. Input CMOS (pin 5,6,7,8,9)
VINL Voltage Low -0.3 0.7 V
VINH Voltage High 1.7 2.8 V
I/O Conn. Input LVDS (pin 3,4)
VIN Voltage Range 0 2.5 V
VINDIFF Differential Voltage 250 600 mV
I/O Conn. +5V (pin 2)
IMAX Maximum current 0 1.15 V
V+5V Pin Voltage 4.5 V VCC – 0.5V
Bias Voltage Source for Sensor Diode
VBIAS Bias Voltage 0 ±450 V Polarity is sensor dependent

Performance characteristics of Timepix3

Symbol Parameter Min Typ Max Units Comment
f Hit-rate 40 MPixels/s with USB 3.0 cable
Data rate 2.4 Gbit/s with USB 3.0 cable
TREAD Frame Readout Time3 33 ms with USB 3.0 cable
dT Time resolution 1.56 ns
FREAD Read-out frequency 320 MHz ½ of maximum ROC freq

Pixel mode hit-rate measurement

The whole detector is exposed to homogenous perpendicular irradiation from X-ray tube operated at 18 kVp with 2 mm Aluminum filter. The measurement type is set to “Pixels” and mode to “ToT+ToA” all other parameters are set to factory defaults (as stored in configuration file delivered with device). The exposure time is set to 0.1 s. The “Clustering” tool of PiXet-Pro is used to analyze measured data. The number of hit pixels per second is drawn as function of X-ray tube current searching for saturation. The real number of events is verified for each step using frame type measurement when all hits are accumulated in single frame.

Sensor parameters

TA = 25°C
Symbol Parameter Si CdTe Units Comment
Thickness 100 300 500 675 1000 µm
σ Energy resolution of energy discrimination threshold (σ @ 23 keV) 0.5 1.1 keV
σ Energy resolution of energy discrimination threshold (σ @ 60 keV) 0.6 1.5 keV
σ Energy resolution in full spectral mode (σ @ 23 keV) 0.7 3.0 keV
σ Energy resolution in full spectral mode (σ @ 60 keV) 1.0 3.6 keV
Typical detectable energy range for X-rays 5 to 60 5 to 500 keV See chart below
Pixel size 55 55 µm

Basic principles, measurement types and modes

The ionizing radiation particle interacts with the sensor material creating an electric charge. This charge is collected by electric field and brought to pixel preamplifier where it is amplified and shaped forming triangular voltage pulse. The amplitude and duration of this pulse is proportional to energy deposited by particle within the pixel. The situation when the voltage pulse amplitude in particular pixel exceeds preselected threshold value is called “event” or “hit”. Each pixel contains three digital counters (10, 14 and 4 bits). These counters are used differently according to measurement type and mode. There are four basic values which can be measured and stored in counters of each pixel:

Measurement modes:

Number of Events number of events (hits) in the pixel during exposure time (this mode is suitable mainly for frame type readout)
Time-over-Threshold (ToT) measured as number of periods of 40 MHz clock signal (25 ns step) when amplifier output signal stays over the energy threshold. The ToT can be transformed to energy in keV using per-pixel-calibration function. The coefficients for per-pixel-calibration are unique for each detector pixel and they are stored in configuration file delivered with device. The energy calibration is valid only for given values of other detector parameters as delivered in configuration file (especially threshold)
Time-of-Arrival (ToA) number of periods of 40 MHz clock signal (25 ns step) from start of exposure till the event is registered by pixel (i.e. pulse in pixel crosses the threshold). The range is 409.6 µs. Additional 16 bits are added in FPGA in readout electronics so that the total range is 26.8 seconds. The additional bits are usable only if the pixel hit rate is below maximal value (see fp in table of Performance characteristics)
Fast-Time-of-Arrival (FToA) time difference between event detection and next clock signal measured with step of 1.5625 ns. Range is 4 bits. The combination of ToA and FToA gives precise time of event detection in nanoseconds using following formula: Time [ns] = ToA*25 – FToA*1.5625 ToA and FTOA are combined together by software. If saved then ToA and FToA are stored as separate items

Measurement types:

Frame type measurement No data is sent out of device during the exposure time. All measured events are accumulated in counters of pixels. Event counter is incremented and ToT is integrated for all events. The measured data is read-out after end of exposure time for all pixels with nonzero content. No measurement can be performed during readout process. Pixel type measurement Information about all hit pixels is read-out immediately and continuously during exposure time. If hit rate is below maximal value (see fp in table of Performance characteristics) then there is virtually no deadtime. Major modes and types of operation (rarely used combinations are shown with gray background):
Type Mode Range Description
Frame (reading all pixels after end of exposure) Event+iToT 10 bit + 14 bit 2 output frames per exposure: 1st Events = Number of events in pixel, 2nd iToT = total time over threshold for all events in pixel.
iToT 14 bit 1 output frame: iToT = total time over threshold for all events in pixel.
ToA 18 bit 1 output frame: ToA+FToA3= Time of Arrival of first event in pixel.
Pixel (reading only hit pixels continuously during exposure) ToT+ToA 10 bit + 18 bit 4 numbers per pixel per event: Position, ToT, ToA and FToA.
ToA 18 bit 3 numbers per pixel per event: Position, ToA and FToA.
Only ToT 10 bit 2 number per pixel per event: Position and ToT.

Device description

+5VDC connector

Main power supply (via standard 5.5/2.1mm barrel connector). Connect after plugging USB connector.

USB 3.0 connector

USB type micro B, Standard USB 3.0 Super-Speed.

I/O Digital connector

Signals on I/O Digital connector are used for synchronization purposes. For details see Synchronization guide for TPX3. Input pins are NOT +5V compatible. Pin 2 (+5V) may be used for power of external circuitry. It is taken directly from +5VDC connector, protected by schottky diode (0.5A max) Pin directions (Input/output) are dependent on polarity of pin 9 (Dir Select).
Table for version APXMD3-Xxx170704
Pin Name Signal type Pin Name Signal type
1 GND 2 +5V
3 Resersved CMOS 0-2.5V 4 Resersved CMOS 0-2.5V
5 Resersved CMOS 0-2.5V 6 Resersved CMOS 0-2.5V
7 NC 8 Resersved CMOS 0-3.3V
9 NC 10 Resersved CMOS 0-3.3V

Table for version APXMD3-Xxx180119
Pin Name Signal type Pin Name Signal type
1 GND 2 +5V
3 CLK p LVDS (2.5V) 4 CLK n LVDS (2.5V)
5 E2 CMOS 0-2.5V 6 E1 CMOS 0-2.5V
7 Trigger Out CMOS 0-2.5V 8 Trigger In CMOS 0-2.5V
9 Dir select CMOS 0-2.5V 10 GND

Mechanical dimensions

Without protection cover

All dimensions are in mm.

With protection cover

All dimensions are in mm.

1 Convertors based on 6LiF or 10B4C for slow neutrons (efficiency up to 4%) or PE for fast neutrons.
2 During Readout time (or Dead time), no signal is collected from the sensor.
3 ToA and FToA are combined together by software automatically. If saved, ToA and FToA are stored as separate items (for Pixel type measurement).


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