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STJ Quick Start Guide v 2.01
April 1, 2021
Page 9
QUICK START GUIDE
STJ OR DIAGNOSTIC PULSER INPUT?
The STJ Analog preamplifiers accept inputs both from the STJ detectors and from a diagnostic input, which
is connected to either the built-in software-controlled pulser or a user-provided signal. We recommend
starting with the built-in pulser to first familiarize the user with the software, settings and data acquisition
procedures. This approach bypasses the complex tasks of biasing the STJ detectors and solving system
grounding and signal integrity issues. Without proper biasing and grounding, the input signals can do
unexpected things.
SYSTEM SETUP
SOFTWARE INSTALLATION
Run the provided ProSpect executable and follow the steps as indicated within the installer.
STJ PREAMPLIFIER INSTALLATION
The custom crate should be connected to detector cryostat via HDDSUB-78 cables (not provided) and a
solid ground connection, and to the power supply using the provided power cable with circular
connectors. It is critical to make a solid ground connection between the custom crate and the detector
cryostat, and to otherwise isolate the two from other ground connections. Ideally the two pieces of
hardware are physically co-located and bolted together. If that’s not possible a thick copper braid may be
sufficient.
•
Signal integrity issues almost always trace back to poor grounding between the custom crate
and the detector cryostat, or improper STJ wiring within the cryostat itself.
•
The custom crate can safely be powered on/off and connections can safely be made while the
PXI crate is powered
Each STJ Analog card in the system should be installed into one of the four right-hand slots in the custom
crate, and connected to its corresponding MPX-32D via 2 Samtec cables and 1 Harting cable.
•
Samtec front-panel connectors are labeled “0-15” or “16-31”. Make sure that every Samtec
cable is connected such that the labels on each end are consistent.
PXI CRATE INSTALLATION
Turn off the PXI crate. Install the required number of MPX-32D modules, power on the PXI crate
connected to the host computer and then re-boot the host computer. After Windows starts you should
get a notification and prompt to install new drivers for each and every MPX-32D module. This is tedious,
but you should only have to do this the first time a slot is occupied.
•
ALWAYS power off the PXI crate before installing or removing MPX-32D cards!
•
Turn on the PXI crate, then re-boot the computer