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KETEK GmbH
KETEK GmbH
Hofer Str. 3
81737 München
Phone +49-89-673467-70
Fax +49-89-673467-77
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Rev. 0
Information furnished by KETEK is believed to be accurate and reliable.
However, no responsibility is assumed by KETEK for its use, nor for any infringements of patents or other rights of third parties that may result from its use. Specifications given in this document subject to change without notice. No license is granted by implication or otherwise under any patent or patent rights of KETEK. Trademarks and registered trademarks are the property of their respective owners.
KETEK GmbH, Hofer Str. 3, D-81737 München, Germany
Tel: +49-(0)89-67346770
Fax: +49-(0)89-67346777 www.ketek.net
©2012 KETEK GmbH. All rights reserved.

1.
Table of Contents ................................................................................................ 3
2.
Revision History .................................................................................................. 3
3.
Features .............................................................................................................. 5
4.
Applications ......................................................................................................... 5
5.
Connection Block Diagram .................................................................................. 5
6.
General Description............................................................................................. 5
7.
Safety .................................................................................................................. 6
8.
General Restrictions and Recommendations ...................................................... 7
9.
Specifications ...................................................................................................... 9
10.
Absolute Maximum Ratings ............................................................................. 9
11.
Ambient Conditions.......................................................................................... 9
12.
ESD Caution .................................................................................................... 9
13.
Pin Configuration and Functional Descriptions .............................................. 10
14.
Typical Performance Characteristics ............................................................. 11
15.
Theory of Operation ....................................................................................... 13
16.
Application and Operation Information........................................................... 15
16.1.
Pulser Input ................................................................................................ 15
16.2.
Shaper Output ............................................................................................ 15
16.3.
Preamplifier Output .................................................................................... 16
16.4.
Operating Voltages..................................................................................... 17
16.5.
Peltier Characteristics ................................................................................ 19
17.
Collimator....................................................................................................... 21
18.
Outline Dimensions........................................................................................ 22
19.
Footprint of SDDs .......................................................................................... 24
20.
Ordering Guide .............................................................................................. 25
21.
Optional ......................................................................................................... 25
22.
Contact .......................................................................................................... 26
12/05 – Revision 0: Initial Version
Rev. 0 Page 3 of 26 KETEK GmbH

Rev. 0 Page 4 of 26 KETEK GmbH

•
Analytical X-Ray Acquisition System including
Power Supplies
Regulators
Preamplifier
Filtering and adjustable voltage dividers
•
Silicon Drift Detector System
• energy resolution down to 127eV FWHM at Mn-K α
• excellent peak-to-background
• operable at an ambient temperature of up to +50°C with excellent performance
• high count rate capability up to 1,000,000 cps
• efficient integrated Peltier element
• no liquid nitrogen cooling required
• radiation hardness during more than 10 years standard count rate exposure
• easy to use
• active areas from 7 to 50mm² available
•
XRF
•
µ-XRF
•
EDX
•
EDS
•
TXRF
•
XRD
•
Handheld
Fig. 1: KETEK AXAS-A Connection Block Diagram
KETEK AXAS-A is the state-of-the-art X-ray detector system based on KETEK VITUS Silicon Drift
Detectors. They are used in applications such as EDX, EDS, XRF, TXRF. Due to their wide operating temperature range they are especially suited for industrial and automotive applications. The highly integrated design including all power supplies is providing a fully functional easy to operate system.
Rev. 0 Page 5 of 26 KETEK GmbH

It is strongly recommended to read this user manual carefully and completely before installing or activating the SDD. Please keep this user manual always with the system for that any operator can get this important information. In case of resale – even when second hand – or in case of scrapping at the end of lifetime this manual has to be given along with the system. Please handle the attached documents “Beryllium Material Data Sheet” and “Statement of contamination…” the same way.
WARNING!
The detector contains a thin, fragile Be window. If this window is damaged, the detector will be destroyed and cannot be repaired.
Be windows damaged due to improper handling are not covered under warranty.
This product uses – a very small amount - of toxic beryllium material at the inner side of the detector foil. Beryllium is preferred as an entrance window coating because it provides a light-tight seal and, further, does not introduce spurious peaks in the measured spectrum. In normal operation there is no danger to get in contact with any toxic materials. If the SDD window was destroyed by accident, follow our safety instructions.
Scrapping at end of lifetime has to be done according to the (local) legal requirements.
Make the “Beryllium Material Data Sheet” available to your waste disposal contractor. Do not scrap the SDD to your domestic waste.
Due to the very thin window foil you should take care neither to touch it with fingers nor to bring other things or materials under test too near to it.
Keep away excessive dust particle streams from the SDD window.
Excessive electrostatic discharge might destroy the window. Take care ESD is well bled off in your application.
Some of the SDD types are evacuated. A damaged entrance window may implode scattering small beryllium particles in the immediate vicinity of the SDD. In this case, rigorously clean the SDD and its surrounding area following all the precautions mentioned in the “Beryllium Material Safety Data Sheet”.
Always keep the SDD protection cap with the system, even if fixed mounted. It’s necessary for cleaning, service and shipping to be able to protect the beryllium window.
CAUTION!
High voltages need to be applied to the detector for use. To prevent electrical shock, do not touch the detector.
Do not drop or cause mechanical shock to the detector. Components inside the detector are mechanically fragile and may be damaged if the unit is dropped.
Avoid temperature shocks. If the detector is out of allowed temperature range, make sure to acclimate slowly.
Avoid air pressure shocks. Especially in evacuated applications take care to ventilate slowly.
Let the protection cap be mounted at the SDD as long as the system isn’t mounted in its end application. Your end application has to be designed that way to make unexpected, damaging contact with the SDD window impossible. Make sure your samples under test might never touch the SDD window.
Do not remove the protective cap from the detector until data is to be taken. The detector window is made from thin beryllium which is extremely brittle and can shatter very easily.
Do not have any object come in contact with the window. Do not touch the detector because the oil from the fingers will cause it to oxidize. Use gloves. The window cannot be repaired. If the window is damaged the detector assembly must be replaced. Be windows damaged due to improper handling will not be covered under warranty. Keep the protective cover nearby at all times and cover the detector when the instrument is not in use.
Rev. 1 Page 6 of 26 KETEK GmbH

Radiation damage to the detector will occur if it is exposed to a high flux environment.
Synchrotron Radiation Beams should be modified with attenuators before they are allowed to strike the detector or the fluorescence target. Damage to the detector will be permanent if the flux from an X-Ray Tube, a strong nuclear radiation source, or an accelerator is not attenuated.
No user serviceable parts inside the units. Refer servicing to KETEK GmbH. To prevent electrical shock, do not remove covers.
Keep the device dry and clean!
Warranty
KETEK GmbH warrants to the original purchaser this instrument to be free from defects in materials and workmanship for a period of one year from shipment. KETEK GmbH will, without charge, repair or replace (at its option) a defective instrument upon return to the factory. This warranty does not apply in the event of misuse or abuse of the instrument or unauthorized alterations or repair. KETEK GmbH shall not be liable for any consequential damages, including without limitation, damages resulting from the loss of use due to failure of this instrument. All products returned under the warranty must be shipped prepaid to the factory with documentation describing the problem and the circumstances under which it was observed. Additionally the statement of contamination must be filled out completely and returned with the product. KETEK must be notified prior to return shipment. The instrument will be evaluated, repaired or replaced, and promptly returned if the warranty claims are substantiated. A nominal fee will be charged for unsubstantiated claims. Please include the model and serial number in all correspondence with KETEK.
Care Instructions
Do not clean the System under any circumstances. Do not use any alcoholic, acid or rubbing cleaning agents.
- avoid touching the entrance window of the detector module. It contains hazardous materials
- Do not open the system
Rev. 1 Page 7 of 26 KETEK GmbH

Rev. 1 Page 8 of 26 KETEK GmbH

Parameter
VOLTAGES positive negative
Conditions/Comments Min Typ Max Tolerance Unit
+11 +12 +13
-11 -12 -13
±1
±1
V
V
CURRENTS positive negative
50
20
250
50
350
150 mA mA
WEIGHT 100mm Finger Length 690 g
These specifications refer to the whole VITUS SDD class. Please refer to the individual SDD datasheet for detailed information.
Parameter
VOLTAGES positive negative
CURRENTS positive
Rating
+18VDC
-18VDC
500mA fused negative 250mA fused
Radiation Hardness @17keV ≤ 10
12
Photons
Stresses beyond those listed under Absolute
Maximum Ratings may cause permanent damage to the device. This is a stress rating only; functional operation of the device at these or any other conditions above those indicated in the applications and operations section of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.
Parameter
OPERATING
Temperature
Humidity
Pressure
Pressure Change
STORAGE
Temperature
Humidity
Min Max Unit
0 60 °C
10
0
0
10
80
1.1
100 mbar/s
60
90
% RH atm
°C
% RH
Conditions non condensing non condensing
ESD (Electrostatic Discharge) sensitive device.
Charged devices and circuit boards can discharge without detection. Although this product features patented or proprietary protection circuitry, damage may occur on devices subjected to high energy ESD. Therefore, proper ESD precautions should be taken to avoid performance degradation or loss of functionality.
Rev. 1 Page 9 of 26 KETEK GmbH

*AXAS-A HD-15 connector
Pin No. Description
1
2
7
8
9
3
4
5
6 Input Voltage positive
Mnemonic
GND
GND
+12V
GND
GND
GND
10
11
12
13
14
15
Input Voltage negative -12V
Temperature Output TempMon
Test Pulse
Input
LED
Power
Indicator
Rev. 1 Page 10 of 26
HD-15
Power Connector *
Preamplifier
Output
Temperature
Output
KETEK GmbH

Fig. 2: Typical KETEK VITUS Silicon Drift Detector Spectrum of H7 active area type SDD with an Fe-55 source, taken with an KETEK preamplifier and an analogue shaping amplifier.
0.7
0.6
0.5
0.4
0.3
0.2
1.0
0.9
0.8
8 µm
12.5 µm
25 µm
0.1
0.0
500 1000 1500 2000
Photon energy (eV)
2500 3000
Fig. 3: Typical transmission of KETEK Silicon Drift Detectors with different Beryllium entrance window thickness
Rev. 1
Fig. 4: Typical transmission of KETEK Silicon Drift Detectors with low energy AP3.3 entrance window
Page 11 of 26 KETEK GmbH

Fig. 5: Typical absorption efficiency of KETEK Silicon Drift Detectors with a thickness of 450µm and 8µm Beryllium window
-40
-45
-50
-55 stable -40°C chip temperature possible up to +50°C ambient stable -45°C chip temperature possible up to +40°C ambient con sta nt f ull
Pel tier
po we r
-60
20 25 30 35 40 45 50
Ambient Temperature (°C)
Fig. 6: Typical control range of Silicon Drift Detector chip temperature at different ambient temperatures
Rev. 1
Fig. 7: Typical calculated energy resolutions of Silicon Drift Detectors for low energies
Page 12 of 26 KETEK GmbH

The silicon bulk of the Silicon Drift Detector (SDD) has to be depleted completely to make the sensor sensitive for incoming photons. By applying a negative voltage to the back contact of the SDD, the detector bulk is completely depleted. An incoming photon will generate a number of electrons and holes dependent on its energy. The holes drift to the back side of the detector formed by the large area back contact whereas the electrons drift to the anode where the accumulated charge can be measured or read out. The drift field for the electrons is applied by a ring structure on one side of the
SDD with a negative voltage at the outer ring (Ring X) and a voltage close to 0V at the innermost ring
(Ring 1).
Fig. 8: Silicon Drift Detector potential diagram
The anode is connected to: a) the gate of the first field effect transistor (FET), b) the feedback capacitance (C
FB
) and c) the cathode of the reset diode (D
RES
). The combination of a) and b), the FET and the feedback capacitance, respectively, forms the first part of a charge sensitive amplifier, used to read out the accumulated electrical charge. The combination forms a transimpedance (current to voltage) and an integrator when connected to the subsequent stages of the pre-amplifier. Therefore the source of the FET has to be connected to ground and the drain voltage and current need to be set appropriately (typically 3V and 3mA). The operating point of the FET is optimized by setting its bulk or substrate voltage.
GND U
OR
Driftfield
-V
U
IR
Anode
Rev. 1
U
BACK
Homogeneous thin entrance window
Fig. 9: Silicon Drift Detector schematic
Page 13 of 26 KETEK GmbH

The FET is operated in a common source configuration. The leakage current sensed at the FET gate causes a ramp signal at the output of the pre-amplifier. The slope of the ramp signal, and thus its frequency, is dependant on the operating temperature. The incoming photons generate short current pulses, with a certain rise time (dependant on the location of interaction of the x-ray with the SDD chip), and a certain duration and amplitude (dependent on the energy of the incoming photon). In turn, these short pulses generate steps superimposed on the pre-amplifier’s ramped output signal. The height of a step contains the information necessary to determine the energy of the interacting photon.
1,5
Preamp Out
Reset Out
1
0,5
0
-0,5
-1
-1,5
0 5 15 20 10
Time [ms]
Fig. 10: Typical KETEK Preamplifier Output Signal including Preamplifier Reset Pulse Output using a KETEK VITUS SDD irradiated with an Fe-55 Source at -35°C Operating Temperature
0,04
0
-0,04
-0,08
Preamp
Out
-0,12
Rev. 1
-0,16
0 20 40 80 100 120 60
Time [µs]
Fig. 11: Zoom of Figure 13, typical KETEK Preamplifier Output Signal including Preamplifier Reset Pulse Output using a KETEK VITUS SDD irradiated with an Fe-55 Source at -35°C Operating Temperature showing step like pulses
Page 14 of 26 KETEK GmbH

For (optimal) operation, SDDs require the application of several voltages and integration with a charge sensitive amplifier and other pulse forming electronics (either analog or digital). Typically, a high voltage DC power supply feeds the drift ring voltages; a high current, linearly regulated, low voltage power supply feeds the Peltier element; and a bipolar, linearly regulated power supply feeds the charge sensitive amplifier and pulse forming electronics.
The drift ring voltages can be generated from a filtered high voltage rail, by using several voltage dividers. Each detector may have individual ring currents. Thus potentiometers should be used for voltage adjustments as the voltage drop at the voltage dividers depends on the ring currents.
Fig. 12: KETEK Silicon Drift Detector connected to typical preamplifier board – block diagram
The Peltier power supply should be regulated with a PI/PID loop to keep the operating temperature of the SDD chip stable. Therefore it is necessary to read out the temperature sensor of the SDD.
16.1. Pulser Input
The BNC connection gives the possibility to connect an external spectroscopic pulser (e.g. ORTEC
419). The pulser output should be negative pulses with maximum amplitude of 10V. The risetime should be in the range of 20 to 200ns with a falltime of a few µs.
16.2. Shaper Output
Disabled. Not available any more.
Rev. 1 Page 15 of 26 KETEK GmbH

16.3. Preamplifier Output
For the design of the preamplifier the FET is used in the common source configuration. Therefore the source of the FET can be connected directly to signal ground. The drain drives the signal. The substrate or bulk should be adjusted to the value given in the datasheet of each single SDD. Also a low pass filter should be used to suppress any noise. Typical values are:
Substrate/Bulk: R
SUB
= 10k Ω , C
SUB
= 4.7µF/16V Tantalum, low ESR
The drain is driven by a simple current source formed by a resistor. Additional low pass filtering is mandatory. Tantalum capacitor with low ESR of at least 100µF should be chosen.
The Drain and Feedback lines should be well separated to avoid any ringing or crosstalk. The
Substrate voltage can be adjusted by a potentiometer.
The Reset circuit includes a current limiter. This will protect the sensitive reset diode mechanism inside the SDD.
Fig. 13: Preamplifier connection block diagram
There are two options for the preamplifier output which can be chosen by the customer: a) Ramped / Reset Type Output Signal:
See figure above. 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 amplitude of 5mV/keV. 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.
Rev. 1 Page 16 of 26 KETEK GmbH

Fig. 14: KETEK AXAS-A exponential decay preamplifier signal output
16.4. Operating Voltages
Several voltages are needed for operating the detector (exact values are given in each detector data sheet), for example:
1. Ring 1 = approx. -20V
2. Ring X = approx. -130V
3. Back = approx. -65V
The detector voltages should be filtered using the following combinations of resistors and capacitors providing low pass filters:
1. Ring 1: R
R1
= 15k Ω , C
R1
= 220nF
2. Ring X: R
RX
= 500k Ω , C
RX
= 47nF/250V
3. Back: R
Back
= 1M Ω , C
Back
= 47nF/250V
Rev. 1 Page 17 of 26 KETEK GmbH

Fig. 15: Operating voltages filtering block diagram
In case of AXAS-A these filters are included. Additionally there are three potentiometers available to adjust the three necessary SDD voltages (R1, RX and Back) to the appropriate voltages necessary for each single SDD.
Before switching on the system, the output-signal of the preamplifier and the shaped signal should be connected to an oscilloscope.
The preamplifier operating voltage must be switched on first.
The detector voltages should be switched on in the following order:
R1 – RX – Back
The voltages to be applied must be set according to the detector datasheet. Typical currents flowing are several µ A through Ring 1 and Ring X (voltage divider) and approx. 1nA for the back contact if the back voltage is applied. R1 and RX currents should be equal!
After switching on the detector voltages the signal of the preamplifier should show a ramp. The ramp period depends on the chip temperature. At -35°C the ramp period should be in the range of several microseconds.
Rev. 1 Page 18 of 26 KETEK GmbH

16.5. Peltier Characteristics
The KETEK Silicon Drift Detectors are provided in three different performance grades, based on the package’s internal atmosphere and size: evacuated TO-8 packages (H7, H20, H30, and H50); evacuated non-TO-8 packages for larger devices (H80, R100); and, low-energy, nitrogen filled TO-8 packages (H7-LE, H15-LE). The three types have different cooling capabilities because of the different internal atmosphere (vacuum or nitrogen) and different sizes.
4
3
H7-LE
H80
H7
2
1
0
-60 -50 -40 -30 -20 -10 0 10 20
Te mpe rature [°C]
Fig. 16: Typical power consumption of the three different KETEK VITUS SDDs
It is strongly recommended to limit the current as mentioned in chapter “10. Absolute Maximum
Ratings”. Stresses above those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. Functional operation of the device at these or any other conditions above those indicated in the applications and operations section of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.
Please note that the behaviour of the Peltiers can vary with changed ambient temperatures. The efficiency of the Peltier elements is increasing approximately by 0.5K for each Kelvin of increasing ambient temperature. Additionally the step response factor will change which will influence the parameters of the control loop for the regulation of the operating temperature.
Rev. 1 Page 19 of 26 KETEK GmbH

20
10
0
100mA
-10
-20
200mA
-30
300mA
-40
-50
-60
0 50 100 150 200
Time [s]
250 300 350
400mA
500mA
700mA
400
Fig. 17: Typical H7 step response functions for different Peltier currents using a diode as temperature sensor with 1µA operating current and 10V compliance voltage.
20
10
100mA
0
200mA
-10
-20
-30
-40
-50
300mA
400mA
500mA
600mA
700mA
800mA
900mA
1000mA
-60
0 50 100 150 200
Time [s]
250 300 350 400
Fig. 18: Typical H80 step response functions for different Peltier currents using a diode as temperature sensor with 1µA operating current and 10V compliance voltage.
20
0
-20
100mA
200mA
300mA
400mA
500mA
600mA
700mA
900mA
-40
Rev. 1
-60
0 50 100 150 200
Time [s]
250 300 350 400
Fig. 19: Typical H7-LE step response functions for different Peltier currents using a diode as temperature sensor with 1µA operating current and 10V compliance voltage.
Page 20 of 26 KETEK GmbH

The KETEK Multilayer Collimator consists of a Tantalum (Ta) foil covered with stacked layers of
Chromium (Cr), Titanium (Ti) and Aluminium (Al). The purity of the layers is ≥ 99%.
All collimators are mounted on-chip.
Optionally, KETEK offers an external outer clip-on collimator VPROTECT. Depending on the application, the geometry of the x-ray beam can differ. To avoid any foreign absorption or fluorescence the additional collimator can optimize the beam geometry.
Fig. 20: KETEK additional external clip-on collimator
Rev. 1 Page 21 of 26 KETEK GmbH

Rev. 1 Page 22 of 26 KETEK GmbH

H7LE H15LE
Ø
H7 H20 H30
H50 H80 R100
Fig. 25: Outline dimensions of the different KETEK VITUS Silicon Drift Detector types
Rev. 1 Page 23 of 26 KETEK GmbH

For H7, H20, H30, H50 SDDs: (Bottom View), M4x6 Screw
Mating connectors:
- Type Tyco Electronics/AMP 6-5330808-5
For H80 and R100 SDDs: (Bottom View), M6x8 Screw
Mating connectors:
- Type Tyco Electronics/AMP 2-5331272-3
- Type Tyco Electronics/AMP 2-5331272-7
Rev. 1 Page 24 of 26 KETEK GmbH

A 5 T 2 O - -
Example :
A5T2T0-H30-ML8BEV: VITUS AXAS-A 450µm SDD Chip with Thermistor as temperature sensor, active area of 30mm² with high peak-to-background ratio, multilayer collimator in a bevelled cap with a
Be window sealed under vacuum.
Optional available are different KETEK products in combination with the VITUS Silicon Drift Detector:
- KETEK Preamplifier: High performance stand-alone preamplifier for SDD applications
- KETEK VIAMP: VITUS SDD in combination with preamplifier
- KETEK AXAS-D: Analytical X-ray Acquisition System - DIGITAL
- KETEK VPROTECT: external collimator
For detailed information please contact KETEK Sales and Marketing Office.
Rev. 1 Page 25 of 26 KETEK GmbH

KETEK Headquarter Sales Office
KETEK GmbH
Hofer Str. 3
81737 München
Email info@ketek.net
Phone +49 (0) 89 673467 70
Fax +49 (0) 89 673467 77 www.ketek.net
Rev. 1 Page 26 of 26 KETEK GmbH