X-123SDD represents the culmination of 15 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-123SDD exemplifies this philosophy by providing in a single package the XR100SDD Silicon Drift X-Ray Detector and its Charge Sensitive Preamplifier; the DP5 Digital Pulse Processor with pulse chaper, MCA, and interface; and the PC5 Power Supply. All that is needed is a +5 Volts DC input and a USB, RS232 or Ethernet connection to your computer.
The X-123SDD combines in a single package Amptek’s high performance X-ray spectroscopy components: (1) the XR-100SDD silicon drift X-ray detector and preamplifier, (2) the DP5 digital pulse processor and MCA, and (3) the PC5 power supply. The result is a complete system which can fit in your hand with no performance compromise. It requires only +5 VDC power and a standard communication interface. With the X-123 anyone can rapidly obtain high quality X-ray spectra.
The X-123SDD uses a silicon drift detector (SDD) similar to a Si-PIN photodiode but with a unique electrode structure to improve energy resolution and increase count rates. The SDD 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 pulse processor is the DP5, a second generation digital pulse processor (DPP) which replaces both the shaping amplifier and MCA found in analog systems. The digital technology improves several key parameters: (1) better performance, specifically better resolution and higher count rates; (2) greater flexibility since more configuration options are available and selected by software, and (3) improved stability and reproducibility. The DPP digitizes the preamplifier output, applies real-time digital processing to the signal, detects the peak amplitude, and bins this in its histogram memory. The spectrum is then transmitted to the user’s computer. The PC5 supplies the power to the detector, including low voltages for the preamps, high voltage to bias the detector, and a supply for the thermoelectric cooler which provides closed loop control with a maximum temperature differential of 85 °C. All of these are under software control. The X-123SDD input power is an unregulated +5 VDC with a current of about 300 mA.
The complete system is packaged in 7 x 10 x 2.5 cm3 aluminum box. The detector is mounted on an extender, with lengths from 0 to 9” (vacuum flanges are available). In its standard configuration only two connections are required: power (+5 VDC) and communications (USB, RS232, or Ethernet). An auxiliary connector provides several additional inputs and outputs used if the X-123SDD will be integrated with other equipment. This includes an MCA gate, timing outputs, and eight SCA outputs. The X-123SDD is supplied with data acquisition and control software. It also includes an Application Programming Interface (API) DLL to integrate the unit with custom software. Optional accessories include software for analyzing X-ray spectra, vacuum accessories, several collimation and mounting options, and X-ray tubes to complete a compact system for X-ray fluorescence.
Figure 4. X-123SDD Architecture and Connection Diagram.
Click here for more information on Amptek silicon drift detectors (SDD).
|Energy Resolution||125 to 140 eV FWHM @ 5.9 keV. Depends on peaking time and temperature.|
|Electronic Noise (typical)||73 eV FWHM (8.7 e- rms)|
|Peak to Background||20,000:1 (ratio of counts from 5.9 keV to 1 keV) (typical)|
|Energy Range||Efficiency >25% for X-rays from 1 to 25 keV. May be used outside this range with lower efficiency.|
|Maximum Count Rate||Depends on peaking time. Recommended maxima with pile-up-rejection enabled are shown below.
|Detector and Preamplifier|
|Detector Type||Silicon Drift Diode (SDD)|
|Detector Area||25 mm2 (collimator area 17 mm2)|
|Detector Thickness||500 µm Click here for efficiency curves.|
|Detector Window Options||Beryllium (Be): 0.5 mil (12.5 µm) or 0.3 mil (8 µm), See transmission curves
C Series: Low energy windows
|Collimator||Multilayer, click here for more information|
|Thermoelectric Cooler||2-stage (85° ΔTmax)|
|Preamplifier Type||Amptek custom reset, charge sensitive.|
|Preamp Conversion Gain||1 mV/keV (typical)|
|Digital Pulse Processor (DPP)|
|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 (A semi-Gaussian amplifier with shaping time t has a peaking time of 2.2t and is comparable in performance with the trapezoidal shape of the same peaking time.)|
|ADC Clock Rate||20 or 80 MHz, 12 bit ADC|
|Peaking Time||30 software selectable peaking times between 0.2 and 102 µs, corresponding to semi-Gaussian shaping times of 0.1 to 45 µs.|
|Flat Top||16 software selectable values for each peaking time (depends on the peaking time), >0.05 µsec.|
|Baseline Restoration||Asymmetric, 16 software selectable slew rate settings.|
|Fast Channel Pulse Pair Resolving Time||120 nsec|
|Dead Time Per Pulse||1.05 times the peaking time. No conversion time.|
|Maximum Count Rate||4x106 sec-1 (periodic). Output count rate of 7x105 sec-1 for a random input of 1.9x106 sec-1.|
|Dead Time Correction||Manual correction based on Fast Channel measurement of ICR. Accurate to 1% for ICR < 1 Mcps under typical conditions.|
|Pulse Selection Options||Pile-up rejection, risetime discrimination, gate|
|Multichannel Analyzer (MCA)|
|Number of Channels||Software selectable to: 8k, 4k, 2k, 1k, 0.5k, or 0.25k channels|
|Bytes per channel||3 bytes (24 bits) - 16.7M counts|
|Acquisition Time||10 msec to 466 days|
|Data Transfer Time||1k channels in 12 milliseconds (USB) or 280 milliseconds (RS-232)|
|Presets||Time, total counts, counts in an ROI, counts in a single channel|
|MCS Timebase||10 millisec/channel to 300 sec/channel|
|External MCA Controls||Gate input: Pulses accepted only when gated on by external logic. Input can be active high or active low. Software controlled.|
|Counters||Slow channel events accepted by MCA, Incoming counts (fast channel counts above threshold), SCA8 counts, event rejected by selection logic, and external event counter. Sixteen ROI counters.|
|Single Channel Analyzers||8 SCAs, independent software selectable LLDs and ULDs, LVCMOS (3.3V) level (TTL compatible)|
|Digital Outputs||Two independent outputs, software selectable between 8 settings including INCOMING_COUNT, PILEUP, MCS_TIMEBASE, etc. LVCMOS (3.3V) levels (TTL compatible).|
|Digital Inputs||Two independent inputs, software selectable for MCA_GATE, EXTERNAL_COUNTER|
|I/O||Two general purpose I/O lines for custom application|
|Digital Oscilloscope||Displays oscilloscope traces on the computer. Software selectable to show shaped output, ADC input, etc., to assist in debugging or optimizing configurations.|
|USB||2.0 full speed (12 Mbps)|
|Serial||Standard RS232 at 115.2k or 57.6k baud|
|Nominal Input Power||+5 VDC at 500 mA (2.5 W) (typical). Current depends strongly on detector ΔT. Ranges from 300 to 800 mA at 5 VDC.|
|Input Range||4 V to 5.5 V (at 0.4 to 0.7 A typical)|
|Initial transient||2 A for <100 µsec|
|High Voltage Supply||Internal multiplier, software control -95 to -1500V (-120 V typ for SDD), negative polarity|
|Cooler Supply||Closed loop controller with ΔTmax = 85 °C|
|Dimensions||7 x 10 x 2.5 cm (2.7 x 3.9 x 1 in) excluding extender|
|Extender Lengths||1.5” (3.8 cm) standard. Options include no extender, 3/8”, 5”, 9”, and vacuum flanges.|
|Weight||180 g (6.3 oz)|
|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 non condensing
Certificate #: CU 72101153 01
Tested to: UL 61010-1: 2009 R10.08
|USB||Standard USB ‘mini-B’ jack. (The X-123SDD does not draw power from the USB.)|
Standard 2.5 mm stereo audio jack.
|Ethernet||Standard Ethernet connector (RJ-45)|
|Power||Hirose MQ172-3PA(55), Mating plug: MQ172-3SA-CV|
2x8 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.
|DPPMCA||The X-123SDD can be controlled by the Amptek DPPMCA display and acquisition software. This software completely controls and configures the X-123SDD, and downloads and displays the data. It and 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-123SDD comes with a free Software Developer's Kit (SDK). The user can use this kit to easily write custom code to control the X-123SDD 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-123SDD 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-123SDD through either the USB, RS-232, 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.|
Figure 5. X-123SDD detector extender options.
Figure 6. X-123SDD with the PA-230SDD preamplifier and housing. This option is the same as the X-123SDD except the detector/preamplifier have been removed from the electronics box and connected with a flexible cable. Provided in order to operate the detector remotely from its electronics box. See the OEM page for more information.
The X-123 can be operated in air or in vacuum down to 10-8 Torr. The X-123 can be located outside the vacuum chamber to detect X-Rays inside the chamber through a standard Conflat compression O-ring port. Optional Model EXV5 or 9 ( 5 or 9 inch) vacuum detector extender is available for this application. Click here for more information on vacuum applications and options.
Figure 7. Resolution vs. Peaking Time for the silicon drift detector (SDD).
Figure 8. Comparison of Resolution vs. Peaking/Shaping Time for Si-PIN and SDD Detectors.
Figure 9. Resolution vs. Input Count Rate for different peaking times for the silicon drift detector (SDD) with the DP5.
The plot also shows the curve of maximum output count rate. Operating to the right of that curve results in less throughput than the maximum despite a higher input rate. See figure 4 below.
Figure 10. Throuhgput with the silicon drift detector (SDD). Due to the detector’s smaller capacitance, a much shorter peaking time is used in the shaping amplifier without sacrificing resolution. Typically 9.6 µs or less is used. This dramatically increases the throughput of the system.
Figure 11. 55Fe spectrum with 4 million counts in the peak channel taken with the silicon drift detector (SDD).
Figure 12. Resolution vs. Energy for Different Peaking Times taken with the silicon drift detector (SDD).
Figure 13. The figure combines the effects of transmission through the Beryllium window (including the protective coating), and interaction in the silicon drift detector (SDD). The low energy portion of the curve is dominated by the thickness of the Beryllium window - either 0.3 mil (8 µm) or 0.5 mil (12.5 µm), while the high energy portion is dominated by the thickness of the active depth of the Silicon drift detector (SDD) - 500 µm.
Efficiency Package: A ZIP file of coefficients and a FAQ about efficiency. This pacakge is provided for general information. It should not be used as a basis for critical quantitative analysis.
Figure 14. XRF of stainless steel SS316 taken with the super silicon drift detector (SDD) and the Mini-X x-ray tube.
Figure 15. RoHS/WEEE PVC sample taken with the super silicon drift detector (SDD) and the Mini-X x-ray tube.
Figure 16. CaCl2 solution (800 ppm Ca, 1200 ppm Cl) taken with super silicon drift detector (SDD) and the Mini-X x-ray tube.
Figure 17. Sulphur in crude oil (1100 ppm) with some KCl taken with super silicon drift detector (SDD) and the Mini-X x-ray tube.
Figure 18. Automotive Catalyst taken with super silicon drift detector (SDD) and the Mini-X x-ray tube.
Figure 19. Platinum (Pt) ring XRF taken with super silicon drift detector (SDD) and the Mini-X x-ray tube.
Figure 20. Dimensions: inches [millimeters].
Figure 21. The X-123SDD is supplied with two types of mounting hardware: right-angle and flat.
Figure 22. X-123 Mounting Plate.
Figure 23. X-123 right angle mounting bracket.
Experimenter's XRF System Includes
SUPER SDD Specifications in PDF (500k).
Digital Pulse Processor FAQ
Application Note AN-SDD-001: Silicon Drift Detector (SDD) at High Count Rates (pdf 500k).
Application Note AN-AMP-003: Si-PIN and Silicon Drift Detector (SDD) Low Energy Performance (pdf 100k).
Application Note AN-SDD-003: Amptek Silicon Drift Detectors
Application Note AN-AMP-005: Comparison of Silicon Drift Detector (SDD) and Si-PIN Detector (pdf 70k).
Revised February 26, 2013