AXAS-A
Analytical X-ray
Acquisition System - Analog
Short Facts
- Analog system with VITUS SDD and reset type preamplifier
- Detector sizes from 7mm² to 50mm² available
- Customized finger lengths available
- Highly integrated design
- Filtering for SDD operating voltages
- SDD operating temperature readout
Sample Spectrum
Figure 1: Typical spectrum of a 7mm² KETEK VITUS SDD in AXAS-A, taken with KETEK Shaper and ADC/MCA at 6µs shaping time.
Throughput
Figure 2, Throughput: The diagram provides the throughput behaviour of the AXAS-A. It shows the dependency of the output count rate with the input count rate for different analogue shaping times. The lower the shaping time, the higher is the maximum throughput for a system.
Energy Resolution
Figure 3, Energy Resolution with Input Count Rate: The energy resolution of the analogue system is dependent on 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 analogue shaping times.
Figure 4, Peak Position: The graph shows the dependency of the peak position of the Mn-Ka line with the input count rate for different analogue shaping times.
Block Diagram
a) Ramped / Reset Type Output Signal:
See figure 5. The output shows a ramped output signal with a range of ±4V maximum and step like pulses for each single photon. These steps have typical amplitudes of 5mV/keV and a positive polarity. Other gains on request.
b) Exponential Decayed / RC Feedback Type Output Signal:
An additional analogue filtering is used right after the Ramped or Reset Type Preamplifier. This filter consists of a RC High Pass Filter, shaping the pulse to an exponential decayed signal. The typical decay time is 6 to 200µs, others on request. An additional gain is provided so the amplitude of each single pulse is typically 10mV/keV. The output signal has a negative polarity.
AXAS-A Pin Assignment
- 15-pole Sub-D Connector (see table)
- exponential decay preamplifier output
- pulser test input
- temperature monitor output in Kelvin/100 [V]
- 2.73 V → 273 K
- power indicator LED for ±12 V
1 | 2 | 3 | 4 | 5 |
PUR | PUR | GND | GND | GND |
6 | 7 | 8 | 9 | 10 |
+12V | GND | GND | GND | -12V |
11 | 12 | 13 | 14 | 15 |
n.c. | n.c. | n.c. | n.c. | TEMP |
Geometries
Figure 6: All AXAS have compact aluminium 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. BNC shaper output not in use (no shaper offered anymore).
Versions and Ordering Codes
Available options for AXAS-A:
VITUS SDD | Guaranteed | Finger | Upper | Vacuum-tightness of snout |
|---|---|---|---|---|
H7, | Premium Class ≤ 133 eV* | 50, | 20 keV or 30 keV | yes / no |
