X-123 X-Ray Detector SystemThe X-123 is a complete X-Ray Detector System in one small box that fits in your hand.

X-123 represents the culmination of 14 years of X-ray detector development at Amptek. Our philosophy has always been to create small, low power, high performance instruments while keeping them simple to operate. The X-123 exemplifies this philosophy by providing in a single package the XR-100CR X-Ray Detector and its Charge Sensitive Preamplifier; the DP5 Digital Pulse Processor with pulse shaper, MCA, and interface; and the PC5 Power Supply. All that is needed is a +5 V DC input and a USB or RS-232 connection to your computer.


  • Compact integrated system
  • Simple to Operate
  • Small Size (2.7 x 3.9 x 1 in, 7 x 10 x 2.5 cm)
  • Low Power (2.5 Watts)
  • Light Weight (6.3 oz, 180 g)
  • USB and RS-232 Communication


  • X-Ray Fluorescence (XRF)
  • RoHS/WEEE Compliance Instrumentation
  • Process Control
  • X-Ray Sorting Machines
  • Art and Archaeology


  • Si-PIN for X-Ray detection
  • 2-Stage thermoelectric cooler
  • Area: 6 to 25 mm2
  • Thickness: 500 µm
  • Multilayer Collimator

Typical Performance

  • Resolution: 145 to 260 eV FWHM at 5.9 keV
  • Optimum energy range: 1 keV to 40 keV
  • Maximum count rate: Up to 2 x 105 cps

Detailed performance depends on detector and configuration, which can be optimized for special applications.

Si-PIN x-ray detector with 149 eV Resolution

Figure 1. 55Fe Spectrum taken with a 6 mm2/500 µm Si-PIN detector.

Contact us for more information today!


X-123 Description

Amptek’s specialty is X-ray spectrometers, which are small, low power, high performance, and simple to operate. The X-123 combines in a single package Amptek’s standard, high performance X-ray spectroscopy components: the XR-100CR detector and preamplifier, DP5 digital pulse processor and MCA, and PC5 power supply. The result is a complete integrated system which can fit in your hand. In many commercially available systems, the preamplifier alone has more size, mass, and power than this integrated system. It requires only 2 connections to run: +5 VDC power and a standard RS-232 or USB bus. With the X-123, anyone can rapidly obtain high quality X-ray spectra.

The typical detector is a Si-PIN photodiode: X-rays interacting in the silicon create an average of one electron/hole pair for every 3.62 eV of energy lost in the silicon, which is the input signal.

The detector is mounted on a thermoelectric cooler along with the input FET and coupled to a custom charge sensitive preamplifier. The thermoelectric cooler reduces the electronic noise in the detector and preamplifier, but the cooling is transparent to the user: it operates like a room temperature system. The charge-sensitive preamplifier uses a novel feedback technique, injecting reset pulses through the high voltage connection to the detector.

The pulse processor is the DP5, a digital pulse processor which replaces both the shaping amplifier and multichannel analyzer (MCA) found in most analog systems. The use of digital technology improves several key parameters: (1) better performance, specifically better resolution and operation at higher count rates; (2) greater flexibility since more configuration options are available and they are selected by software over a RS-232 interface, and (3) improved stability and reproducibility. The DP5 digitizes the preamplifier output, applies real-time digital processing to the signal, detects the peak amplitude (digitally), and bins this value in its histogramming memory, generating an energy spectrum. The spectrum is then transmitted over the DP5’s interface to the user’s computer. The Amptek DP5 has 6 main function blocks to implement these functions: (1) an analog prefilter; (2) an ADC; (3) a digital pulse shaper; (4) pulse selection logic; (5) histogram logic, and (6) interfacing hardware (which includes a microcontroller) and software.

The power supply is Amptek’s PC5, a single board. The input is approximately +5 VDC with a current of about 200 mA. The PC5 uses switching supplies to produce all the low voltages required for the digital processor and the preamplifier. It also includes a high voltage multiplier to produce the detector bias voltage, up to 400 V, and supply for the thermoelectric cooler which provides closed loop control with a maximum temperature differential of 85 °C. Both of these supplies are adjusted at the factory for a particular detector.

The complete system is packaged in 7 x 10 x 2.5 cm³ aluminum box, with the detector mounted on an extender. In its standard configuration, only two connections are required: power (+5 VDC) and serial (either USB or RS-232). The DP5 board supports several additional inputs and outputs, if the X-123 will be integrated with other equipment. This includes an MCA gate, a memory buffer select signal, timing outputs, and SCA ouputs. Please contact Amptek or see the DP5 specifications for further information.

X-123 Architecture and Connection Diagram
Figure 2. X-123 Architecture and Connection Diagram


X-123 Specifications

System Performance

Energy Resolution 145 to 260 eV FWHM @5.9 keV. Depends on detector, peaking time, and temperature.
Energy Range Efficiency is >25% for X-rays from 1.5 to 25 keV. May be used outside this range with lower efficiency.
Maximum Count Rate Depends on peaking time. Recommended maxima for 50% dead time with pile-up-rejection enabled are shown below.

DP5 Peaking Time (µs) 2.4 6.4 25.6
Shaping Time (µs) 1.0 2.9 11.6
Recommended max rate 1.2 x 105 4.6 x 104 1.2 x 104

Detector and Preamplifier

Detector Type Si-PIN (also available with SDD or CdTe)
Detector Area 6 mm2 to 25 mm2
Detector Thickness 500 µm
Be Window Thickness 1 mil (25 µm) or 0.5 mil (12.5 µm)
Collimator Multilayer
Thermoelectric Cooler 2-stage
Preamplifier Type Amptek custom design with reset through the HV connection.

Pulse Processor

Gain Combination of coarse and fine gain yields overall gain continuously adjustable from 0.84 to 127.5.
Coarse Gain Software selectable from 1.12 to 102 in 16 log steps. 1.12, 2.49, 3.78, 5.26, 6.56, 8.39, 10.10, 11.31, 14.56, 17.77, 22.42, 30.83, 38.18, 47.47, 66.26, 102.0
Fine Gain Software selectable, 0.75 to 1.25, 10 bit resolution.
Full Scale 1000 mV input pulse @ x1 gain
Gain Stability <20 ppm/°C (typical)
Pulse Shape Trapezoidal
Peaking Time 24 software selectable peaking times between 0.8 and 102 µs, approximately log spaced, corresponding to semi-gaussian shaping times of 0.4 to 45 µs.
Dead Time Total dead time is 1.05 times the peaking time. No conversion time.
Fast Channel Pulse Pair Resolving Time 120 ns


Number of Channels Software selectable to: 8k, 4k, 2k, 1k, 0.5k, or 0.25k channels
Presets Time, total counts, counts in an ROI, counts in a single channel


USB 2.0 full speed (12 Mbps)
Serial Standard RS-232 at 115.2k or 57.6k baud
Ethernet 10base-T


Nominal Input +5 VDC at 500 mA (2.5 W) (typical). Current depends strongly on detector ΔT. Ranges from 300 to 800 mA at 5 VDC. AC adapter provided.
Input Range 4 V to 6 V (300 to 200 mA, 500 mA max)
High Voltage Supply Internal multiplier, adjustable to 400 V
Cooler Supply Closed loop controller with Delta_Tmax = 85 °C

General and Environmental

Operating temperature -20 °C to +50 °C
Warranty Period 1 Year
Typical Device Lifetime 5 to 10 years, depending on use
Storage and Shipping Long term storage: 10+ years in dry environment
Typical Storage and Shipping: -20 °C to +50 °C, 10 to 90% humidity noncondensing
Compliance RoHS Compliant
TUV Certification
Certificate #: CU 72101153 01
Tested to: UL 61010-1: 2009 R10.08
CAN/CSA-C22.2 61010-1-04+GI1


USB Standard USB Mini jack
RS232 Standard 2.5 mm stereo audio jack.

Tip Transmit To PC Receive DB9 pin 2 (DB25 pin 3)
Ring Receive To PC Transmit DB9 pin 3 (DB25 pin 2)
Sleeve Ground To PC Ground DB9 pin 5 (DB25 pin 7)
Ethernet Standard Ethernet connector (RJ-45)
Power Hirose MQ172-3PA(55), Mating plug: MQ172-3SA-CV
Auxiliary 2 x 8 16-pin 2 mm spacing (Samtec part number ASP-135096-01). Mates with cable assembly (Samtec P/N TCMD-08-S-XX.XX-01. Top row odd pins, bottom row even pins. Top right pin = 1, bottom right pin = 2.

Pin # Name Pin # Name
1 SCA1 2 SCA2
3 SCA3 4 SCA4
5 SCA5 6 SCA6
7 SCA7 8 SCA8
9 AUX_IN_1 10 AUX_OUT_1
11 AUX_IN_2 12 AUX_OUT_2
13 IO2 14 IO3
15 GND 16 GND

Interface Software

DPPMCA The X-123 can be controlled by the Amptek DPPMCA display and acquisition software. This software completely controls and configures the X-123, and downloads and displays the data. It supports regions of interest (ROI), calibrations, peak searching, and so on. The DPPMCA software includes a seamless interface to the XRF-FP quantitative X-ray analysis software package. Runs under Windows XP PRO SP3 or later. Click here for the software download page.
SDK The X-123 comes with a free Software Developer’s Kit (SDK). The user can use this kit to easily write custom code to control the X-123 for custom applications or to interface it to a larger system. Examples are provided in VB, VC++, etc. Click here for the software download page.
VB Demonstration Software The VB demonstration software runs on a personal computer and permits the user to set the X-123 parameters, to start and stop data acquisition, and to save data files. It is provided with source code and can be modified by the user. This software is intended as an example of how to manually control the X-123 through either the USB, RS232, or Ethernet interface using the most basic calls without the SDK. This is primarily needed as an example when writing software for non-Windows platforms. Click here for the software download page.

Use of Collimators

Most of Amptek’s detectors contain internal collimators to improve spectral quality. X-rays interacting near the edges of the active volume of the detector may produce small pulses due to partial charge collection. These pulses result in artifacts in the spectrum which, for some applications, obscure the signal of interest. The internal collimator restricts X-rays to the active volume, where clean signals are produced. Depending on the type of detector, collimators can

  • improve peak to background (P/B)
  • eliminate edge effects
  • eliminate false peaks

Vacuum Operation

The X-123 can be operated in air or in vacuum down to 10-8 Torr. The X-123 can be connected to the vacuum chamber through a standard Conflat compression O-ring port. Optional Model EXV5 (5 inch) or EXV9 (9 inch) vacuum detector extender is available for this application. See figure 5 above. Click here for more information on vacuum applications and options.


Resolution vs. Peaking Time for Si-PIN and SDD Detectors
Figure 3. Resolution vs. Peaking Time for Si-PIN and SDD Detectors.

Resolution vs. input count rate (ICR) for various peaking times
Figure 4. Resolution vs. input count rate (ICR) for various peaking times.

PX5 Throughput with SDD
Figure 5. Throughput, input vs. output count rate.

Efficiency Curves

Figure 6 (linear). Shows the intrinsic full energy detection efficiency for the X-123 Si-PIN detectors. This efficiency corresponds to the probability that an X-ray will enter the front of the detector and deposit all of its energy inside the detector via the photoelectric effect.

Figure 7 (log). Shows the probability of a photon undergoing any interaction, along with the probability of a photoelectric interaction which results in total energy deposition. As shown, the photoelectric effect is dominant at low energies but at higher energies above about 40 keV the photons undergo Compton scattering, depositing less than the full energy in the detector.

Both figures above combine the effects of transmission through the Beryllium window (including the protective coating), and interaction in the silicon detector. The low energy portion of the curves is dominated by the thickness of the Beryllium window, while the high energy portion is dominated by the thickness of the active depth of the Si detector. Depending on the window chosen, 90% of the incident photons reach the detector at energies ranging from 2 to 3 keV. Depending on the detector chosen, 90% of the photons are detected at energies up to 9 to 12 keV.

Efficiency Package: A ZIP file of coefficients and a FAQ about efficiency. This package is provided for general information. It should not be used as a basis for critical quantitative analysis.


RoHS/WEEE Compliance

The RoHS / WEEE [Restriction of Hazardous Substances / Waste from Electrical and Electronic Equipment] directive requires that the electronics industry certify that products comply with maximum concentration amounts of particular elements and compounds (Cr VI, Pb, Cd, Hg, Br PBB/PBDE) by July, 2006. The X-123 can be used to verify compliance with the RoHS/WEEE requirements as part of a quality assurance program, via XRF. It permits users to measure the concentration of the specified elements, quickly, accurately, and non-destructively. Companies can verify supplier compliance and demonstrate their own compliance. The X-123 provides OEMs and end users with a powerful X-Ray Spectrometer system in one convenient, small, easy to use instrument that can be quickly implimented to minimize time to market. No additional engineering is required on the spectrometer end since all the connections have been made internally. All that is needed is a +5 VDC input power and a USB or RS232 connection to a computer.

The X-123 does not sacrifice performance for size. The resolution for the 5.9 keV peak of 55Fe is 145 eV FWHM to 260 eV FWHM depending on the detector type and peaking time. Since the X-123 is a complete packaged spectrometer, it is the perfect choice for fast-track product development and will provide the OEM with the quickest time to market.

Figure 8. RoHS/WEEE Example Spectrum.

X-123 Typical Si-PIN Results

multi-element fluorescence spectrum
Figure 9. X-ray fluorescence (XRF) of multi-element sample from 109Cd.

Figure 10. X-Ray Fluorescence (XRF) of lead (Pb) from 109Cd.

Figure 11. X-Ray Fluorescence (XRF) of a few locations on a PC board from 109Cd.


Figure 12. X-Ray Fluorescence (XRF) of a various elements from 109Cd.

Options & Additional Info


Figure 13. X-123 detector extender options.

X-123SDD modified for use with the PA-230 preamplifier and housing
Figure 14. X-123 with the PA-230 preamplifier and housing (Option 6). This option features the same performance as the X-123; the detector/preamplifier have been removed from the electronics box and connected with a flexible cable. This option allows you to locate the detector remotely from its electronics box. See the OEM page for more information.

Vacuum Operation

The X-123 can be operated in air or in vacuum down to 10-8 Torr. The X-123 can be connected to the vacuum chamber through a standard Conflat compression O-ring port. Optional Model EXV5 (5 inch) or EXV9 (9 inch) vacuum detector extender is available for this application. See Figure 13 above. Click here for more information on vacuum applications and options.


Mechanical Dimensions

X-123 Mechanical Dimensions

X-123 Rear View Showing Connections

Figure 15.

Mounting Hardware

Figure 16. X-123 with mounting plate and right angle bracket.

Figure 17. X-123 Mounting Plate.

Figure 18. X-123 right angle mounting bracket.

Download the X-123 STP File

Mechanical Dimensions of Amptek Si-PIN and SDD detectors
Mechanical Dimensions of Amptek Si-PIN and SDD detectors


All results on this page are typical performance values at full cooling; please Contact Us to discuss guaranteed performance under different operating conditions.  Specifications subject to change without notice.

Reset Preamplifier Application Note

X-123 Specifications in PDF format