Digital system with VITUS SDD, reset type low-noise preamplifier, high performance DPP and all power supplies in compact housing.


Unique Features

  • Detector sizes from 7 mm² to 50 mm²

  • Customized finger length available
  • Highly integrated design

  • Filtering for SDD operating voltages
  • SDD operating temperature readout

  • Analog and digital outputs available

  • High performance Digital Pulse Processor DPP2

  • USB2.0 and RS232 interface

  • Peaking times from 0.1 µs to 24 µs


Figure 1: Typical Fe-55 spectrum of a 30 mm² KETEK VITUS SDD in AXAS-D, taken with KETEK DPP2 at 1 µs peaking time.

Ketek AXAS-D Spectrum

Ketek AXAS-D Throughput


Figure 2: The diagram provides the throughput behavior of the AXAS-D. It shows the dependency of the output count rate with the input count rate for different peaking times. The lower the peaking time, the higher is the maximum throughput for a system.

Energy Resolution

Figure 3: Energy Resolution with Input Count Rate acquired with KETEK DPP2: The energy resolution of the digital system is absolutely independent from the input count rate. The graph shows the dependency of the Full Width at half maximum with the incoming photons (input count rate) for different peaking times.

Ketek AXAS-D Energy Resolution

AXAS-D peak position vs. input count rate

Figure 4: Peak Position: The graph shows the independency of the peak position of the Mn-Kα line with the input count rate for different peaking times. Acquired with KETEK DPP2.


Figure 5: The backplane of the AXAS-D with all available connectors is shown. For the operation a ±12 V power supply is needed. The analog and digital outputs can be operated simultaneously.

AXAS-A/D connectors

Ketek AXAS-D Geometries


Figure 6: All AXAS have compact aluminum housings plated with Nickel. All screws are stainless steel and the systems can be fixed to a plate by using M3 screws. The mounting plates are compatible for all AXAS.

Analog Output Signal

Figure 7: The AXAS-D is equipped also with an analog output which can be used together with the digital output simultaneously. The shape of this analog output signal (ramped reset type) is shown on the graph. The ramp amplitude is approx. 3 V.

Ramped reset type analog output signal

Ramp with steps

Figure 8: If the detector is exposed to an X-ray radiation small steps are visible in the ramp signal. The height of each step corresponds to the energy of the single photon (one event).

Technical Data

Operating temperature range 0 to +50 °C Storage temperature range 0 to +50°C
Temperature monitor Thermistor Power supply ±12 VDC; KETEK APS-L power supply 220/110 VAC
Signal output Low noise preamplifier Signal form Ramped reset type +1 V to -2 V; 5 mV/keV
Output connector (analog) LEMO FFS.00.250 Digital interfaces USB 2.0, RS232 (on request)
Vacuum tightness Optional; He leakage rate <10-6 mbar · l/s Channel depth 24 bit
Number of channels max. 8192 ADC 14 bit
Peaking time range 0.1 to 24 µs in 24 steps Maximum read-out speed 1 ms (@1024 channels)
Software parameters Digital gain, threshold, peaking time etc. Clock frequency 40 MHz

Available Options

* with low-energy window
CUBE Class
VITUS SDD Guaranteed FWHM [Mn Kα] @ 1 µs PT Finger length [mm] Vacuum-tightness of snout
H7 ≤ 133 eV 50, 100 (standard), 160, 200 Yes (optionally)
H20 ≤ 133 eV 50, 100 (standard), 160, 200 Yes (optionally)
H30 ≤ 133 eV 50, 100 (standard), 160, 200 Yes (optionally)
H50 ≤ 133 eV 50, 100 (standard), 160, 200 Yes (optionally)
H7LE* ≤ 133 eV 50, 100 (standard), 160, 200 Yes (optionally)
H20LE* ≤ 133 eV 50, 100 (standard), 160, 200 Yes (optionally)