XR-100SDD Silicon Drift Detector SDD-Obsolete

The SDD is now Obsolete, please see our FAST SDD.

The XR-100SDD is a thermoelectrically cooled solid-state silicon drift detector (SDD) and preamplifier. It is recommended for applications requiring the best energy resolution, very high-count rates, and lowest X-ray energies. Its performance, small size, and low cost make it the ideal detector for many laboratory and OEM X-ray spectroscopy applications, including EDS and XRF.

Amptek XR-100SDD detector with PX5 signal processor system.

Product Details

Overview

The XR-100SDD can provide a resolution of 125 eV FWHM at the Mn Kα line (electronic noise of 4.5 electrons rms), a peak to background of 20,000:1, an output count rate over 500 kcps, and can detect X-rays down to the Be Kα line (110 eV). It has a 25 mm2 active area and is 500 μm thick.

The standard XR-100SDD has a 0.5 mil Be window for good efficiency above 2 keV. For lower energies, the optional Patented C-Series windows available with our FAST SDD® provide good efficiency down to the B line. For count rates >200 kcps, the FAST SDD® is recommended.

In the XR-100SDD, the detector is mounted on an extender (several different lengths are available), with the preamplifier in the attached metal box. It requires a separate signal processor and power supplies; Amptek’s PX5 is recommended and is ideally suited for most laboratory uses. The same SDD detectors are available in the smaller X-123SDD package or with smaller preamplifiers for OEMs and custom systems.

Amptek recently brought silicon wafer manufacturing in-house and improved the process. The result is a detector with lower noise, lower leakage current, better charge collection, and uniformity from detector to detector.

Lower noise → Better resolution down to 125 eV FWHM
Lower leakage current → Higher temperature operation (save battery life)
Better charge collection → Better photopeak shape (no tailing)
Quality → Detectors have consistent performance allowing for easier calibrations

The XR-100SDD is an enhanced version of Amptek’s thermoelectrically cooled X-ray detectors. It uses a silicon drift detector (SDD), a silicon photodiode with a special electrode configuration giving very low capacitance, resulting in low electronic noise at high frequencies. This provides the improved energy resolution and count rate. The SDD uses special “drift” electrodes to guide the charge into its anode, hence the name “drift detector”.

As with Amptek’s other XR-100 detectors, the photodiode is mounted on a two stage thermoelectric cooler, keeping the detector and its input JFET at approximately -55 °C, reducing electronic noise without cryogenic liquid nitrogen. This cooling permits high performance in a compact, convenient package, and has been a core enabler of the portable XRF analyzer.

The hermetic TO-8 package of the detector has a light tight, vacuum tight, thin Be window to enable soft X-ray detection. There is vacuum inside the enclosure for optimum cooling. The XR-100SDD detector includes an internal multilayer collimator to minimize background and spectral artifacts. It has a reset-style preamplifier.

In the XR-100SDD, the preamplifier is enclosed in a metal box, 3.0 x 1.75 x 1.125 in (76.2 x 44.45 x 28.58 mm), with the detector on an extender (available lengths range from 3/8” to 9” or 9.53 to 228.6 mm). The XR-100SDD with a 5” or 9” extender is suitable for vacuum measurements, using the optional CP75 vacuum flange. Alternate preamplifiers are available, recommended for OEMs or where space is limited.

Features

125 eV FWHM Resolution @ 5.9 keV
High Peak-to-Background Ratio – 20,000:1
25 mm2 – collimated to 17 mm2
500 µm Thick
2-Stage Thermoelectric Cooler
Cooling ΔT>85 K
Temperature Monitor
Thin Beryllium 0.3 or 0.5 mil
Patented C-Series windows available with FAST SDD
Multilayer Collimator
Hermetic Package (TO-8)
Wide Detection Range
Easy to Operate
Radiation Hard
Applications
X-Ray Fluorescence
RoHS/WEEE
Precious metals
Alloy analysis
Light elements
EDS
Teaching and Research
Process Control
Mössbauer Spectrometers
PIXE
Wavelength dispersive XRF

Figure 1. 55Fe spectrum taken with the Amptek silicon drift detector (SDD).

Performance

SDD detector resolution versus peaking time at different operating temperatures.

Figure 2. Resolution remains largely stable across detector temperatures, with minimal variation at peaking times below 4 µs, which are commonly used with SDD detectors.

SDD detector resolution versus input count rate for different peaking times and maximum throughput conditions.

Figure 4. Resolution vs. Input Count Rate for different peaking times for the silicon drift detector (SDD) with the DP5.

SDD detector throughput graph showing output count rate versus input count rate for different peaking times.

Figure 4.Throughput with an SDD is significantly increased because its lower capacitance allows shorter peaking times (typically ≤4 µs) without compromising energy resolution.

SDD detector Fe-55 X-ray spectrum showing energy resolution, escape peaks, and peak-to-background performance.

Figure 6. 55Fe spectrum with 4 million counts in the peak channel taken with the silicon drift detector (SDD).

SDD detector resolution versus X-ray energy at different peaking times.

Figure 6. 55Fe spectrum with 4 million counts in the peak channel taken with the silicon drift detector (SDD).

FAST SDD detector efficiency and energy resolution versus X-ray energy graph.

Figure 7. Resolution vs. Energy for Different Peaking Times taken with the silicon drift detector (SDD).

Specifications

Detector Type	Silicon Drift Detector (SDD)
Detector Area	25 mm2 – collimated to 17 mm2
Silicon Thickness	500 µm
Collimator	Internal Multilayer
Energy Resolution @ 5.9 keV (55Fe)	125 – 135 eV FWHM at 11.2 µs peaking time
Peak to Background	20,000:1 (ratio of counts from 5.9 keV to 1 keV) (typical)
Detector Window Options	Beryllium (Be): 0.5 mil (12.5 µm) or 0.3 mil (8 µm) Patented C-Series: C1 and C2 low energy windows available with FastSDD
Charge Sensitive Preamplifier	Amptek custom reset preamplifier.
Gain Stability	<20 ppm/°C (typical)
XR-100SDD Case Size	3.00 x 1.75 x 1.13 in (7.6 x 4.4 x 2.9 cm)
XR-100SDD Weight	4.4 ounces (125 g)
Total Power	<2 Watt
Warranty Period	1 Year
Typical Device Lifetime	5 to 10 years, depending on use
Operation conditions	-35 °C to +50 °C
Storage and Shipping	Long term storage: 10+ years in dry environment Typical Storage and Shipping: -40 °C to +85 °C, 10 to 90% humidity noncondensing
	TUV Certification Certificate #: CU 72072412 02 Tested to: UL 61010-1: 2004 R7 .05 CAN/CSA-C22.2 61010-1: 2004

Inputs

Preamp Power	±8 to 9 V @ 15 mA with no more than 50 mV peak-to-peak noise
Detector Power	-100 to -180 V @ 25 µA very stable <0.1% variation
Cooler Power	Current = 450 mA maximum, voltage = 3.5 V maximum with <100 mV peak-to-peak noise Note: When the XR-100SDD is provided without an Amptek DPP, it includes its own closed loop temperature controller. When shipped with an Amptek DPP, temperature control is done by the DPP. (Delta_Tmax=85°C)

Outputs

Preamplifier Sensitivity	0.8 mV/keV typical
Preamplifier Polarity	Positive signal output (1 kohm maximum load)
Preamplifier Feedback	Reset
Preamplifier Output Rise Time	<60 ns
Temperature Monitor Sensitivity	PX5: direct reading in Kelvin through software.

XR_100SDD Connectors

Preamp Output	BNC coaxial connector
Power and Signal	6-Pin LEMO connector (Part# ERA.1S.306.CLL)
Interconnect Cable	XR-100SDD to PX5: 6-Pin LEMO (Part# FFA.1S.306.CLAC57) to 6-Pin LEMO (5 ft length) XR-100SDD stand-alone: 6-Pin LEMO (Part# FFA.1S.306.CLAC57) to 9-Pin D (5 ft length)

XR-100SDD 6-Pin LEMO Connector Pin Out

Pin 1	Temperature monitor diode
Pin 2	-H.V. Detector Bias, -100 to -180 V
Pin 3	-9 V Preamp power
Pin 4	+9 V Preamp power
Pin 5	Cooler power return
Pin 6	Cooler power 0 to +3.5 V @ 450 mA
Case	Ground and shield

NOTE

The silicon drift detector (SDD) requires negative high voltage and produces a positive preamplifier output. This is the opposite of the Si-PIN which requires positive high voltage and produces a negative preamplifier output.

The PX5 can produce both negative and positive high voltage. When the PX5 is ordered with an XR-100SDD, the PX5 is set for negative high voltage. Using a Si-PIN XR-100CR with a negative high voltage setting will destroy the Si-PIN XR-100CR and will not be covered under warranty. Likewise, if the PX5 was ordered with a Si-PIN XR-100CR, using a positive high voltage with an XR-100SDD will destroy the silicon drift detector (SDD) detector and not be covered under warranty.

Applications

SS316 stainless steel XRF spectrum measured using a silicon drift detector and Mini-X X-ray tube.

Figure 9. XRF of stainless steel SS316 taken with the silicon drift detector (SDD) and the Mini-X x-ray tube.

RoHS/WEEE PVC sample XRF spectrum measured using a silicon drift detector and Mini-X X-ray tube.

Figure 10. RoHS/WEEE PVC sample taken with the silicon drift detector (SDD) and the Mini-X x-ray tube.

Calcium chloride solution XRF spectrum measured using a silicon drift detector and Mini-X X-ray tube.

Figure 11. CaCl2 solution (800 ppm Ca, 1200 ppm Cl) taken with silicon drift detector (SDD) and the Mini-X x-ray tube.

Sulfur in crude oil XRF spectrum measured using a silicon drift detector and Mini-X X-ray tube.

Figure 12. Sulphur in crude oil (1100 ppm) with some KCl taken with silicon drift detector (SDD) and the Mini-X x-ray tube.

Automotive catalyst XRF spectrum measured using a silicon drift detector and Mini-X X-ray tube.

Figure 13. Automotive Catalyst taken with silicon drift detector (SDD) and the Mini-X x-ray tube.

Platinum ring XRF spectrum measured using a silicon drift detector and Mini-X X-ray tube.

Figure 14. Platinum (Pt) ring XRF taken with silicon drift detector (SDD) and the Mini-X x-ray tube.

Options Additional Info

Signal Processor/Power Supply Modules

PX5 Digital Pulse Processor, MCA and Power Supply

Power to the XR-100SDD is provided by the PX5 Digital Pulse Processor and Power Supply. The PX5 is DC powered by an AC adapter and provides a variable Digital Pulse Processing Amplifier (0.200 µs to 100 µs peaking time), the MCA function, and all power supplies for the detector.

The XR-100SDD/PX5 systems ensures stable operation in less than one minute from power turn-on.

PX5 digital pulse processor architecture and connection diagram for XR-100SDD detector systems.

Block diagram of a PX5 system with an Amptek XR-100SDD detector, supporting multiple detector and preamplifier configurations with varying pinouts and voltages.

DP5/PC5 OEM Digital Pulse Processor, MCA, and Power Supply

XR-100SDD with the DP5 and PC5 is an option that requires some assembly and possibly a custom enclosure depending on the application on the part of the customer.

PX5-HPGe detector system with digital pulse processor, MCA, and power supply connections.

Figure 15. Standard XR-100 box connected to the DP5 and PC5.

Window Options and Thicknesses

Amptek SDDs are available with either beryllium windows, or our Patented C-Series windows. The Be options are Paralyne coated (to prevent gas diffusion), and are supplied in two thicknesses, 0.3 mil or 0.5 mil (8 or 12 μm). The Patented C-Series windows are designed for low Z element detection down to Beryllium (Be).

Options and Accessories
C-Series Windows
Collimator Kit for high flux applications
External Collimator
Vacuum Accessories
OEM Applications

XR-100SDD detector extender options with multiple mounting and housing configurations.

Figure 17. XR-100SDD Detector Extender Options.

Internal Multilayer Collimator

All of Amptek’s Si detectors contain internal multilayer 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.

A multilayer collimator is made by progressively using lower Z materials. Each layer acts as an absorber to the fluorescence peaks of the previous layer. The final layer will be of the lowest Z material whose fluorescence peaks are of low enough energy to be outside the anticipated X-ray detection range.

Amptek has developed a state-of-the-art internal Multilayer Collimator (ML). The base metal is 100 µm of tungsten (W), the first layer is 35 µm of chromium (Cr), the second layer is 15 µm of titanium (Ti), and the last layer is 75 µm of aluminum (Al).

Additional Information

Selection Guide
Efficiency Package (zip file)
Art and Archaeology
X-Ray Fluorescence – A Description
X-Ray Emission Line Chart
Glossary PDF
Publications
History of XR100 Resolution
Digital Pulse Processor FAQ PDF

Mechnicals

1.5 Inch Extender (standard)

FAST SDD detector with 1.5-inch extender showing mechanical dimensions and mounting configuration.

Figure 19. All dimensions in inches ±0.005. XR-100 STP File

No Extender

FAST SDD detector housing without extender showing mechanical dimensions and connector layout.

Figure 20. All dimensions in inches ±0.005.

General AXR (T0-8) Mechanical Dimensions

FAST SDD detector mechanical dimensions and geometry diagram.

Figure 21. All dimensions in inches ±0.005. TO-8 STP File

Typical detector Geometry

FAST SDD detector mechanical geometry showing window, collimator, detector, and thermoelectric cooler dimensions.

Figure 22. Typical Detector Geometry.

Detector Type	Area/Thickness	R_det (mm)	A_det (mm²)	R_coll (mm)	A_coll (mm²)	L_coll (mm)	L_det (mm)
SDD	25 mm²/500 µm	2.82	25.0	2.33	17.0	0.9	1.4
Si-PIN	6 mm²/500 µm	1.38	6.0	1.19	4.4	1.0	1.7
Si-PIN	13 mm²/500 µm	2.03	13.0	1.88	11.1	1.0	1.7
Si-PIN	25 mm²/500 µm	2.82	25.0	2.62	21.5	1.0	1.7

XR-100 STP File

Detector (TO-8) STP File