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. This makes it the best performing silicon drift detector available and the true state-of-the-art.
The FAST SDD® represents Amptek’s highest performance silicon drift detector (SDD), capable of count rates over 1,000,000 CPS (counts per second) while maintaining excellent resolution. The FAST SDD® is also available with our Patented C-Series (Si3N4) low energy windows for soft x-ray analysis.
Unlike our conventional SDDs which use a junction gate field-effect transistor (JFET) inside the hermetically sealed TO-8 package, along with an external preamplifier, the FAST SDD uses a complementary metal-oxide-semiconductor (CMOS) preamplifier inside the TO-8 package, and replaces the JFET with a metal-oxide-semiconductor field-effect transistor (MOSFET). This significantly reduces capacitance, providing much lower series noise and yielding improved resolution at very short peaking times. The FAST SDD® uses the same detector but with a preamplifier giving lower noise at short peaking times. Improved (lower) resolution enables isolation/separation of fluorescent X-rays with close energy values where peaks would otherwise overlap, permitting users better identification all of the elements in their sample(s). Short peaking times also yield significant improvements in count rates; more counts provide better statistics.
|124 eV FWHM||4 µs|
|126 eV FWHM||1 µs|
|134 eV FWHM||0.2 µs|
|160 eV FWHM||0.05 µs|
Table 1. Resolution vs. Peaking Time for the FAST SDD®.
Figure 1. Resolution vs. peaking time for the FAST SDD® and standard SDD.
Figure 2. Resolution vs. peaking time at different detector temperatures. Note that there is little change in resolution over temperature for the peaking times that are typically used with the FAST SDD® (<1µs).
Figure 3. Energy Resolution and Count Rate: This plot shows how the energy resolution at 5.9 keV is related to the output count rate for Amptek’s X-ray detectors, as a function of the pulse shaping time and the equivalent peaking time in a digital processor. These are typical values at full cooling (220K). For example, at a Tpeak of 9.6 microseconds (equivalent to 4.0 microsecond pulse shaping time) the output count rate at 50% dead time is 18 kcps. This is a function only of the pulse processing so is the same for all detectors. The energy resolution for a 6 mm2 Si-PIN is just under 160 eV FWHM while for a 25 mm2 SDD it is 130 eV FWHM.
Figure 4. Throughput for the FAST SDD®.
Figure 5. Resolution vs. Input Counts Rate (ICR) for Various Peaking Times for FAST SDD®.
Figure 5. Energy resolution, efficiency, and X-ray energy: This plot shows how the intrinsic efficiency (top) and energy resolution (bottom) depend on the X-ray energy.
In the bottom plot, the black curve represents “Fano broadening”, the theoretical limit with a Si based detectors, arising from quantum fluctuations in the charge production process. The colored curves represent the combination of Fano broadening and intrinsic electronic noise under optimum conditions (full cooling and long peaking time). The detector selection is most important at the lowest energies because Fano broadening dominates at high enough energies.
In the top plot, the efficiency at low energies is determined by transmission through the window and detector dead layer. The efficiency at high energies is determined by attenuation in the active depth of the detector. A Si detector with Be window is recommended between about 2 and 30 keV. A Si detector with a C1 or C2 window is recommended at lower energies, while a CdTe detector is best at energies above 30 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.
|Detector Type||Silicon Drift Detector (SDD) with CMOS preamplifier|
|Detector Size||25 mm2 - collimated to 17 mm2
Also available 70 mm2 - collimated to 50 mm2
|Silicon Thickness||500 µm|
|Collimator||Internal MultiLayer Collimator (ML)|
|Energy Resolution @ 5.9 keV (55Fe)||122 - 129 eV FWHM at 4 µs peaking time (guaranteed)|
|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 (Si3N4) Low energy windows
|Charge Sensitive Preamplifier||CMOS|
|Gain Stability||<20 ppm/°C (typical)|
|Detector module: TO-8 package (0.640 in. high including pins, 0.600 in. diameter)
XR100 box: 3.00 x 1.75 x 1.13 in (7.6 x 4.4 x 2.9 cm) excluding extender
X-123 box: 2.7 x 3.9 x 1 in (7 x 10 x 2.5 cm ) excluding extender
OEM configurations vary
|Detector module: 0.14 oz (4.1 g)
XR100 box: 4.4 ounces (125 g)
X-123 box: 6.3 oz (180 g)
OEM configurations vary
|Total Power||<2 Watt|
|Warranty Period||1 Year|
|Typical Device Lifetime||5 to 10 years, depending on use|
|Operation conditions||-35°C to +80°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 non condensing
Certificate #: CU 72072412 02
Tested to: UL 61010-1: 2004 R7 .05
CAN/CSA-C22.2 61010-1: 2004
|Preamp Power||XR100 configuration: ±8 V @ 15 mA with no more than 50 mV peak-to-peak noise
OEM configuration (PA210/230 or X-123): ±5 V
|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: the XR-100SDD includes its own temperature controller
|Preamplifier Sensitivity||3.6 mV/keV typical (may vary for different detectors)|
|Preamplifier Polarity||Positive signal output (1 kohm maximum load)|
|Temperature Monitor Sensitivity||Varies with configuration
When used with PX5, DP5, or X-123: direct reading in Kelvin through software.
|Preamplifier Output Rise Time||<35 ns|
The 25 mm2 FAST SDD is available with the standard Amptek options and OEM configurations.
|The XR-100FAST SDD with the PX5||The FAST SDD with its preamplifier is available in several OEM configurations||The X-123FAST SDD configuration includes the detector, preamplifier, digital processor and power supplies all in one box||The FAST SDD is compatible with all Amptek vacuum accessories|
Figure 6. Stainless Steel 316 Spectrum taken in 1 second with the FAST SDD®.
The below table displays the quantitative analysis of the data in figure 4. This spectrum was taken in 1 second with the FAST SDD®.
|Element||Certified Concentration||Fast SDD® Result in 1 second|
|V||0.05||0.16 ± 0.28|
|Cr||18.45||18.32 ± 0.80|
|Mn||1.63||0.40 ± 0.55|
|Fe||64.51||65.89 ± 1.64|
|Co||0.10||0.00 ± 0.40|
|Ni||12.18||12.56 ± 0.47|
|Cu||0.17||0.19 ± 0.02|
|Mo||2.38||2.34 ± 0.08|
Figure 7. Solder spectrum taken in 1 second (1 µs peaking time) with the FAST SDD®.
Figure 8. Multielement standard taken with the FAST SDD® at different count rates up to 1 Mcps.
The Neutron star Interior Composition Explorer (NICER) is an International Space Station (ISS) payload devoted to the study of neutron stars through soft X-ray timing. The heart of the instrument is an aligned collection of 56 Amptek silicon drift detectors (SDD) with C Series Windows and X-ray “concentrator” optics (XRC) pairs. Each XRC collects X-rays over a large geometric area from a roughly 30 arcmin2 region of the sky and focuses them onto a small SDD. The Amptek FAST SDD® detects individual photons, recording their energies with good (few percent) spectral resolution and their detection times to an unprecedented 100 nanoseconds RMS relative to Universal Time. Together, this assemblage provides a high signal-to-noise-ratio photon-counting capability within the 0.2-12 keV X-ray band, perfectly matched to the typical spectra of neutron stars as well as a broad collection of other astrophysical sources.
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.