Silicon Drift Detector (SDD)CountsSDD
SDD
The Amptek Silicon Drift Detectors (SDD) represent a breakthrough in x-ray detector technology byproviding “off-the-shelf” performance previously available only from expensive cryogenically cooled systems.
SDD
25 mm² x 500 μm
SDD
5.9 keV
⁵⁵FeSDDeV FWHM
SDD
11.2 μs peaking time
SDD
100,000 CPS
P/B Ratio: 20,000/1
SDD
Energy (keV)
SDD
SFeatures
SDD• 125 eV FWHM Resolution @ 5.9 keV
XR-100SDD• High Peak-to-Background Ratio - 20,000:1
SDD• 25 mm x 500  µm• 11.2 μs Peaking TimeSDD• 100,000 CPS• USB Controlled
SDD• No Liquid Nitrogen
SDDApplications• X-Ray Fluorescence
X-Ray Detector and Digital Pulse
SDD• RoHS / WEEE Compliance XRF
Processor with MCA• OEM & Special Applications
SDD• Process Control
X-123SDD• ResearchSDD
The XR-100SDD and X-123SDD Silicon Drift Detectors (SDD) are the latest additions to Amptek’s line
SDDof x-ray detectors that revolutionized the industry.
Their high performance, small size, and low cost
SDD
make them the ideal detector for OEM hand-held
applications to bench-top analyzers.
SDD
The SDD enables extremely high count rate applications with excellent energy resolution. The deSDD
tector is housed inside the same TO-8 package as
Complete X-Ray Spectrometer Includes:
Amptek’s other detectors, so its form-factor is a di1 Silicon Drift Detector and Preamplifier SDD
rect replacement for current systems and is compat2 Digital Pulse Processor and MCA
ible with all Amptek accessories and options.
SDD
3 Power SupplySDD
SDD
AMPTEK Inc.
SDD
www.amptek.com

125Figure 1. 55Fe Spectrum with ilicon Drift Detector (SDD).

214 DeAngelo Drive, Bedford, MA 01730-2204 USA

Tel:+1 781 275-2242 Fax:+1 781 275-3470 E-mail: sales@amptek.com

XR-100SDD
X-123SDD

Specifications
GeneralDetector Type

XR-100SDD Outputs

Detector Size

Silicon Drift Detector (SDD)
25 mm2

Silicon Thickness

500 µm.  See Figure 5

Energy Resolution 125 - 140 eV FWHM at 11.2 µs peaking@ 5.9 keV (55Fe)
time
Peak to Background20000:1 (ratio of counts from 5.9 keV to1 keV)

Background
Counts<3 x 10-3/s, 2 keV to 150 keV

Detector Be Window Thickness

0.5 mil (12.5 µm).  See Figure 5CollimatorInternal MultiLayer Collimator (ML)

Charge Sensitive
Preamplifier

Amptek custom design with reset

Gain Stability<20 ppm/°C (typical)

Case Size
XR-100SDD 3.00 x 1.75 x 1.13 in (7.6 x 4.4 x 2.9 cm)
X-123SDD 3.94 x 2.67 x 1.0 in (10.0 x 6.78 x 2.54 cm)
Weight
XR-100SDD 4.4 ounces (125 g)
X-123SDD 6.7 ounces (190 g)
Total Power
XR-100SDD <1 Watt
X-123SDD 2.5 Watt (typical)
Warranty Period

1 YearDevice Lifetime

Typical 5 to 10 years, depending on use

Storage &Shipping

Long-term Storage: 10+ years in dry environment
Typical Storage & Shipping: -20°C to+50°C, 10 to 90% humidity noncondensing

Operation
conditions

0°C to +50°C  

OEMCompatible with all Amptek OEM configurations

XR-100SDD Inputs
Preamp Power±8 to 9 V @ 15 mA with no more than
50 mV peak-to-peak noise

Detector Power
XR-100SDD -95 to -150 V @ 25 µA, very stable <0.1%variation
X-123SDD -95 to -1500 V (typical -120 V)
Cooler Power
Current 350 mA maximum
Voltage 3.5 V maximum with <100 mV peak-topeak noise
Note: The XR-100SDD includes its own temperature controller

Preamplifier
Sensitivity 1 mV/keV typical (may vary for differentdetectors)
Polarity Positive signal output (1 kΩ max. load)
Feedback Reset
Temperature Mon- PX5/X-123: direct reading in Kelvinitor Sensitivity
through software.

NoteThe SDD requires negative high voltage and produces a positive preamplifier output.  This is the opposite of the standard
Si-PIN which requires positive high voltage and produces anegative preamplifier output.
When ordered in an XR100SDD/PX5 configuration, the PX5
is equipped with a negative high voltage supply.  The newPX5 is also equipped with a positive high voltage supply.  Itcan be used with all Amptek detector types, as well as, withmany other radiation detectors and preamplifiers, including
HPGe detectors and scintillators.

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; and/oreliminate false peaks.
For more information please see: http://www.amptek.com/xrspectr.html#edge

Vacuum Operation
The XR-100SDD can be operated in air or in vacuum down to10-8 Torr.  There are two ways the XR-100SDD can be operated in vacuum:1) The entire XR-100SDD detector and preamplifier box canbe placed inside the chamber. In order to avoid overheating and dissipate the 1 Watt of power needed to operate theXR-100SDD, good heat conduction to the chamber walls
should be provided by using the four mounting holes.  An
optional Model 9DVF 9-Pin D vacuum feedthrough connector on a Conflat is available to connect the XR-100SDD to aPX5 outside the vacuum chamber.
2) The XR-100SDD or X-123SDD can be located outside
the vacuum chamber to detect X-Rays inside the chamber through a standard Conflat compression O-ring port.  
Optional Model EXV9 (9 inch) vacuum detector extenderis available for this application. Click here for more information on vacuum applications and options.
For more information see: http://www.amptek.com/exv.html

Additional System Information and Performance
The XR-100SDD and X-123SDD are new high performance x-ray detector, preamplifier, and cooler system using a thermoelectrically cooled silicon drift detector (SDD).  Also mounted on the 2-stage cooler are the input FET and a novel feedback circuit.  Thesecomponents are kept at approximately -55 °C, and are monitored by an internal temperature sensor.  The hermetic TO-8 packageof the detector has a light tight, vacuum tight thin Beryllium window to enable soft x-ray detection.
A SDD is a type of photodiode, functionally similar to a PIN photodiode, but with a unique electrode structure to improve
performance.  Amptek’s SDDs are optimized for X-ray spectroscopy.  The key advantage of the SDD is that it has much lower capacitance than a conventional diode of the same area, therefore reducing electronic noise at short shaping times.  For X-ray spectroscopy, an SDD has better energy resolution while operating at much higher count rates than a conventional diode.  The SDD uses a
special electrode structure to guide the electrons to a very small, low capacitance anode.

Resolution for Different Peaking Times

300

Maximum Output
Count Rate280

0.2 μs260240220

0.2 µs0.4 µs0.8 µs
1.6 µs2.4 µs4.8 µs
9.6 µs200
180
160
1401200.8 μs
1.6 μs2.4 μs100

OCR (kcps)

Resolution 5.9 keV FWHM

Throughput

1000

4.8 μs109.6 μs25.6 μs

1.0E+0711                                       10                                    100                                 1000

Figure 2. Resolution vs. Input Count Rate for different peaking times for
the 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 3.

Figure 3. Throughput with the 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.

1.0E+03

1.0E+04

1.0E+05

1.0E+06

ICR (cps)

ICR (kcps)

Resolution vs Peaking Time
Efficiency / Transmission

160
155150145140135130125

510Peaking Time (µs)

1520

Figure 4. Resolution vs. Peaking Time for the SDD.

Resolution vs. Peaking/Shaping Time for
Si-PIN and SDD Detectors

Efficiency of
500 µm Si

Transmission
through Be
0.3 mil (8 µm)

0.5 mil (12.5 µm)

Total

0.1

Photoelectric

0.01
0Efficiency and Transmission

1Resolution (eV FWHM @ 5.9 keV)

165

0.1

1Energy (keV)

10100

Figure 5. The figure combines the effects of transmission through the Be window (including the protective coating), and interaction in the SDD. The low
energy portion of the curve is dominated by the thickness of the Be window- either 0.3 mil (8 µm) or 0.5 mil (12.5 µm), while the high energy portion isdominated by the thickness of the active depth of the SDD - 500 µm.

Resolution vs. Energy for Different Peaking Time
350

Resolution (eV FWHM)

300
250
200
150
100

Figure 6. Comparison of Resolution vs. Peaking/Shaping Timefor Si-PIN and SDD Detectors

50Fano Limit
No Electronic Noise
Electronic Noise

0.6 μs0.8 μs2.4 μs4.8 μs
9.6 μs25.6 μs00                   5                  10                15                 20                 25                30Energy (keV)

Figure 7. Resolution vs. Energy for Different Peaking Times taken with the SDD.

Application Spectra

Experimenter’s XRF Kit with SDD

OEM Components
PA-230 Preamplifier in Heat Sink

Complete XRF System Includes:
X-123SDD Complete
Spectrometer

Detector

Mini-X USB Controlled X-Ray Tube
XRF-FP Quantitative Analysis
Software
MP1 XRF Mounting Plate

The X-123SDD and Mini-X onthe MP1 mounting plate.

PC5 Power Supply

See Experimenter’s XRF Kit: http://www.amptek.com/xrfkit.html

AMPTEK Inc. 14 DeAngelo Drive, Bedford, MA 01730-2204 USA

Tel:+1 781 275-2242 Fax:+1 781 275-3470 E-mail: sales@amptek.com

DP5 Digital Pulse Processor,     Pulse Shaper, + MCA

www.amptek.com