Amptek XR-100CR User manual

OPERATING MANUAL
XR-100CR
X-RAY DETECTOR SYSTEM
and PX2CR POWER SUPPLY / SHAPER
Revision 13
October 2003
AMPTEK Inc. 14 DeAngelo Drive, Bedford, MA 01730-2204
Tele: [phone] Fax: [phone] E-mail: [email protected] www.amptek.com

Amptek Inc. XR-100CR Manual
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Table of Contents
1CAUTION ........................................................................................................................................3
2SYSTEM SPECIFIC PERFORMANCE ...........................................................................................5
3CONNECTION DIAGRAM: XR-100CR/PX2CR/MCA8000A (Figure 1) .........................................7
4OPERATING NOTES FOR THE XR-100CR CONNECTED TO THE PX2CR ................................8
5RISE TIME DISCRIMINATION (RTD) IN THE PX2CR AMPLIFIER .............................................10
6PILEUP REJECTION (PU) IN THE PX2CR AMPLIFIER ..............................................................10
7INPUT COUNT RATE (ICR) IN THE PX2CR AMPLIFIER ............................................................11
8XR100CR / PX2CR Reset Waveforms..........................................................................................12
9XR-100CR / PX2CR TROUBLESHOOTING .................................................................................13
10 XR-100CR CONNECTION DIAGRAM WITHOUT PX2CR (Figure 2) ..........................................14
11 OPERATING NOTES FOR THE XR-100CR WITHOUT THE PX2CR .........................................15
11.1 Equipment Required ................................................................................................15
11.2 Absolute Maximum Ratings .....................................................................................15
11.3 6-Pin Lemo Connector on the XR-100CR (Lemo Part# ERA.1S.306.CLL) .............15
11.4 9-Pin Cable D-Connector to PX2CR or External Power (standard 9-Pin D)............15
11.5 Connections and Turn-On Procedure (see figure 2)................................................15
12 PROCEDURE TO LOWER THE HIGH VOLTAGE BIAS IN THE DETECTOR............................17
13 WARRANTY .................................................................................................................................18
13.1 Technical Questions ................................................................................................18
14 INTERNAL CONNECTIONS BETWEEN AXRCR / XR-100CR / PX2CR.....................................19
15 PX2CR FRONT AND BACK PANELS..........................................................................................20
16 XR-100CR EFFICIENCY CURVES ..............................................................................................21
17 APPLICATION NOTES.................................................................................................................22
17.1 Use of Collimators....................................................................................................22
17.2 Detector Edge Effects (25 mm2 and 5 mm2, 500 m thick) ......................................23
18 X-RAY FLUORESCENCE (XRF) – A DESCRIPTION..................................................................24
19 XR-100CR-EX1.5 MECHANICAL DIMENSIONS .........................................................................26
20 XR-100CR SELECTION CHART (as of 7/08) ..............................................................................27
21 AMPTEK K AND L EMISSION LINE LOOKUP CHART ...............................................................28
22 PX2CR POWER SUPPLY SCHEMATIC FOR XR-100CR (Figure 3) ..........................................29
23 PX2CR SHAPER SCHEMATIC....................................................................................................30

Amptek Inc. XR-100CR Manual
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1 CAUTION
1. DO NOT DROP OR CAUSE MECHANICAL SHOCK TO THE XR-100CR DETECTOR
2. DO NOT DAMAGE the AXRCR detector element.
3. DO NOT REMOVE the red protective cap from the AXRCR detector until data is to be taken.
The detector window is made from thin beryllium (0.001 in / 25 µm thick) which is extremely
brittle and can shatter very easily. Do not have any object come in contact with the window. Also,
do not touch the window because the oil from the fingers will cause it to oxidize. The window
cannot be repaired. If the window shatters the detector assembly must be replaced. Keep the red
protective cover nearby at all times and cover the AXRCR detector when the instrument is not in
use. Beryllium windows damaged by improper handling will not be covered by the warranty.
4. AVOID holding the XR-100CR in the hand. Heat from the body will increase the operating
temperature of the detector and increase the leaking current. Increased leaking current in the
detector will result in poor energy resolution. Keep the XR-100CR away from incandescent lamps
to avoid overheating.
5. BEST PERFORMANCE of the XR-100CR can be achieved by mounting it by one or two of its
mounting holes to a metal plate. This will increase the surface area and allow the detector to run 4
to 6 degrees colder. A colder detector will result in better energy resolution. As a rule, if the
correct heat sinking has been provided, the XR-100CR should NOT be warm to the touch.
6. 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.
A RADIATION DAMAGED DETECTOR WILL NOT BE COVERED UNDER
WARRANTY.
7. PX2CR WARNING: The Amplifier and Rise Time Discriminator (RTD) inside the PX2CR box
have been carefully adjusted at the factory for maximum performance.
CHANGING THE SETTINGS TO THE AMPLIFIER AND RTD INSIDE THE PX2CR BOX
WILL VOID WARRANTY.
8. PLACE THE XR100CR AWAY FROM the PX2, and away from any computer terminal or CRT
monitor. Keep the XR100CR detector away from magnetic fields.

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2 SYSTEM SPECIFIC PERFORMANCE
Replace this page with the graph for the specific detector and any other additional system specific
information.

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Blank page

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3 CONNECTION DIAGRAM: XR-100CR/PX2CR/MCA8000A (Figure 1)
Pocket MCA
MCA
8000A
AMP TEK
INPUT
GATE 1 GATE 2
I/O
SERIAL PORT
LEMO
XR100CR
POWER
AMP TEK
XR-100CR PX2CR
POWER SUPPLY
&
AMPLIFIER
AC POWER
ICR
PU GATE
TEST
AMP IN
AMP OUT
OUT IEC 320
BNC
BNC
LEMO
LEMO
PERSONAL
COMPUTER
DESKTOP
LAPTOP
HP200LX
DE9
-OPTIONAL-
COUNTER
-OPTIONAL-
PULSE
GENERATOR
DE9
BNC
BNC
BNC BNC
SERIAL PORT
CONTROL
and DISPLAY

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4 OPERATING NOTES FOR THE XR-100CR CONNECTED TO THE PX2CR
1. Turn the power to the PX2CR OFF.
2. Connect the 9-Pin D-Connector from the XR-100CR to the PX2CR.
3. Connect the Output of the XR-100CR (OUT) directly to the Input of the PX2CR (AMP IN) with
a BNC cable. DO NOT terminate the cable with a 50 termination.
4. Connect the Output of the PX2CR (AMP OUT) directly to the input of a Multichannel Analyzer
(MCA). DO NOT terminate the cable with a 50 termination.
5. Connect the +/- TEMP from the PX2CR to a µA meter.
6. Turn the AC power to the PX2CR ON via the rear panel switch.
7. Observe the µA meter. As the temperature of the cooler decreases, the µA meter will decrease
from 293 µA to about 250 µA. The temperature monitor IC provides 1 µA per 1°K. Please note:
room temperature = 293°K = 20°C.
NOTE:
Depending on the detector type, the internal temperature monitor could be a Diode sensor instead of an
IC sensor. If it is an IC sensor, the above instructions are valid. If it is a Diode sensor, please see
below.
For detectors with Diode temperature sensors:
The +/- TEMP MONITOR on
the PX2CR will be measured in
mV instead of A. The graph to
the right is used to cross
reference the mV reading to the
actual detector temperature in
degrees C.
If the PX2CR was ordered
together with a detector that has
a Diode temperature sensor, it
has been modified at the factory
to directly read in mV across the
(+ TEMP -) banana terminals.
This modified PX2CR is set at
the factory to provide 800 A of
current through the diode and
provide a TEMP reading in mV
only.
If a customer has both types of detectors with IC and Diode temperature sensors, the measurement can
still be made with a standard PX2CR that has not been modified exclusively for the Diode sensor. For
the IC operation, perform the A measurement as described in steps 5, 6, and 7 above. For Diode
operation, connect the two + and - terminals together with a banana shorting plug and measure mV
between the shorted + and - banana plug and the PX2CR chassis ground. Then cross reference the mV
reading to the graph in order to get degrees C.
XR100 Temperature Sensor Calibration
1N914 Lot #P1839244 I = 800uA
y = -0.4329x + 281.5
-65
-55
-45
-35
-25
-15
-5
5
15
25
590 610 630 650 670 690 710 730 750 770 790 810
mV
deg C
7/19/02

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8. Once the temperature has stabilized (about one minute), start taking data on the MCA. For
normal operation, there is no need to monitor the temperature. In order to avoid extraneous
noise pick-up into the detector, disconnect the +/-TEMP wires from the PX2CR. Just turn
the power ON to the PX2CR, wait a few seconds and start taking data.
9. The XR-100CR can be stimulated by either an X-Ray source or through the TEST input
connector. A positive (100 ns rise, 1 ms fall) test pulse of 20 mV will produce an output from
the XR-100CR roughly equivalent to a 20 keV X-Ray.
NOTE: For 5 mm2and 25 mm2 detectors (500 m thick) with internal collimators only:
Set the pulse generator to 4 Volts and the PX2CR GAIN to 2. This will produce an
output from the AMP OUT of the PX2CR of about 1 Volt.
10. Please Note: The standard PX2CR Shaping Amplifier has a "triangular" fixed shaping time
constant of about 12 µs, (see graph below). Optional PX2CR with 6 µs or 20 µs shaping time
constants are also available. An external NIM amplifier, compatible with a reset type
preamplifier, can also be used if other shaping time constants are desirable. Power to the XR-
100CR can be supplied through the PX2CR even if an external amplifier is used.
Pulse Widths:
12 s Shaper: 22 s
6 s Shaper: 15 s
20 s Shaper: 54 s

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5 RISE TIME DISCRIMINATION (RTD) IN THE PX2CR AMPLIFIER
A Rise Time Discriminator circuit has been implemented in the PX2CR amplifier. See Specifications
under THEORY OF OPERATION. When RTD is active (RTD switch up on the front panel), the
shaped pulses are internally gated and only pulses corresponding to "good" X-Ray events are allowed
to be sent to the MCA for analysis. The RTD internal threshold is set to about 2 keV. If energies less
than 2 keV are to be detected do not use the RTD function. The graph bellow shows the shape of the
output pulse when RTD is activated.
6 PILEUP REJECTION (PU) IN THE PX2CR AMPLIFIER
A PileUp rejection circuit has been implemented in the PX2CR amplifier. The PU Gate located in the
back panel of the PX2CR produces a positive TTL pulse. DO NOT terminate this signal with 50 .
The PU Gate should be connected to a device of impedance greater than 1 k .
For the duration of this gate, the Multichannel
Analyzer (MCA) must reject any detected
pulse. The PU Gate at the back of the
PX2CR (bottom trace in plot) also combines
the gate-off pulse to the MCA due to the reset
preamplifier (see next page).
When using the AMPTEK MCA8000 or
MCA8000A Multichannel Analyzer, the PU
Gate from the PX2CR should be connected to
GATE 1 of the MCA.