Styx StX S1 Produkthandbuch
StX S1
Cosmic Ray
Neutron Detector
Technical
Reference Manual
Notice
This document contains proprietary information of the StyX Neutronica GmbH. StyX Neutronica
provides the information and data included in this document for your benefit, but it is not possible
to entirely verify and test all information, in all circumstances, particularly information relating to
non-StyX-Neutronica manufactured products. StyX Neutronica makes neither warranty nor represents
relating to the quality, content, or adequacy of this information. The information in this document is
subject to change without notice. Although every effort has been made to ensure the accuracy of this
manual, StyX Neutronica shall not be liable for any errors, incidental, or consequential damages in
connection with the furnishing, performance, or use of this manual or examples herein. StyX Neutronica
assumes no responsibility for damage or loss resulting from the use of this manual, for loss or claims
by third parties, which may arise through the use of Reference Manual or for any damage as a result
of malfunction or repair.
January 27, 2023
StyX Neutronica GmbH
Cecil-Taylor-Ring 12-18, 68309 Mannheim
Germany
Copyright ©2022 Styx Neutronica GmbH, all rights reserved.
Contents
1 General setup and functions 1
1.1 Safety instructions ........................................ 1
1.2 StX S1 Components ....................................... 2
2 Operation 5
2.1 Installation and start-up ..................................... 5
2.1.1 Setup ........................................... 5
2.1.2 Sensor start ....................................... 5
2.1.3 Sensor operation ..................................... 6
2.1.4 Service and transport .................................. 8
2.2 Software configuration ...................................... 8
2.3 Logger data ............................................ 12
Appendix 14
A Technical specifications ..................................... 14
i
ii
Part 1
General setup and functions
1.1 Safety instructions
•
Do not modify the electronics of AC-powered devices. Before starting the instrument ensure
hardware integrity.
•
The product is a high voltage device. In operation the amplifier, the cables and connectors to the
proportional counter tubes can carry high voltages above 1000 V. Also when switched off, due to
built-in capacities high electrostatic voltages can occur. As there are no electric currents above
0.01 mA there is no direct danger to the human body. Yet, by improper handling damages can
be inflicted to other electronic devices. Please contact the manufacturer in case of uncertainties
regarding the handling.
•
Contrary to other proportional counter tubes, this device does not contain any dangerous gases.
•
The logger casing (IP 66) and the sensor are protected against splash water. Intrusion of water
can damage the electronics. Please keep all parts of the instrument closed during operation.
•
The supply voltage of the logger should be 12 V and can be in the range 9–24 V. The I
2
C
communication with external devices operates at 3.3 V levels.
•The sensor can be operated at temperatures of -20 ◦C to 45 ◦C.
1
1.2 StX S1 Components
Figure 1.1: The full detection sys-
tem.
The model series StX S1 consists of the components:
- a base unit with the neutron detector,
- amplifier and digitizer (nCatcher) ,
- a logger,
- additional sensors for environmental variables
- a mounting pod
- PV panel and battery for independent operation
The following connectivity features are offered:
- multi-level display to check the detector state,
- UART interface for serial communication, detector settings and data
transfer,
- I2C interface for data transmission,
- GSM/LTE/NB-IoT data transfer.
In the displayed configuration the detector StX S1, PV Panel and
environmental sensors are mounted on a single pole.
Detector Base Unit
The main component of the Cosmic Ray Neutron Detector is the base
unit. It consists of a HDPE casing with a thickness of 2.4 cm and the
dimensions of 146 cm
×∅
18 cm. It contains one tube with a length of
125 cm, which contains a coated copper foil as a converter and Ar:CO
2
as a counting gas.
nCatcher
The single-channel amplifier is used to read out neutron pulses from
the counting tube. It is operated by an ATmega328P microcontroller
and is connected by a CAT6 RJ45cable of up to 3 m to the logger
for the CRP models or up to 20 m for the CRPX nCatcher models.
It communicates via a 5 V I
2
C interface. The amplifier records all
signals above a given threshold and measures pulse height and pulse
length with a millisecond timestamp. These events are recorded in a
buffer, which allows for an independent operation of the nCatcher for
approximately one minute, depending on the rate.
Logger
The logger acts as the central control unit of the sensor. It collects
data from the neutron counters as well as a number additional sensors
for environmental variables. The data is stored on an SD Card and optionally transmitted via GSM. It
also supplies the attached sensors with 3.3 V, 5 V and 12 V. The logger is located in the logger casing
which also houses the battery as well as the charge controller.
The main processor of the logger is a SAM3X8E ARM Cortex-M3 CPU. It features
2
•onboard environmental sensors for temperature, air pressure and relative humidity,
•a temperature-stabilized real time clock,
•a status display,
•an SD card slot for FAT/FAT32 formatted cards up to 4 GB.
•
RJ45 (ethernet) connectors for I
2
C for environmental sensors, I
2
C for nCatcher units, differential
I2C for nCatcher units, serial lines for external GPS units,
•an SDI-12 connector for environmental sensors,
•(optionally) an internal 2G, 3G, 4G or NB-IoT modem for telemetry.
Logger, nCatcher and sensors can be operated asynchronously as the logger uses several buffers to
store volatile data. Fig. 1.2 shows the main components of the data flow. One or more nCatcher units
record pulses from counting tubes. These are stored in an internal ring buffer and are transmitted
upon request to the logger. The logger likewise uses a ring buffer to store events before storing them
to the SD card or transmitting them to a data receiver or modem.
Event
Buffer
[64]
new
Event Event
Buffer
[512]
2
I C
Store/Send
Buffer
GPS V
RTC Temp
Hum
Pres
GSM
SD
UART
nCatcher(s) Central Unit
tube(s)
read write
write
write
send
Figure 1.2: Data structure for the sensor DAQ.
3
Figure 1.3: Logger front side with 12 V-in, on/off switch, display switch, SD card slot, display and USB
connector.
Figure 1.4: Logger back side with SIM card slot, SDI-12 connector, GSM antenna connector, RJ45 connectors
for external devices including cosmic-ray detectors and GPS antenna.
4
Part 2
Operation
2.1 Installation and start-up
2.1.1 Setup
See the detailed description in the manual ’Cosmic Ray Detector - Mounting Instructions’.
2.1.2 Sensor start
•
Switch on the device by setting the main power switch to the ’On’ position. The status display
shows the StyX Neutronica logo.
•The logger checks whether there is an SD card inserted.
–
If yes, it checks the existence of a correct configuration file
central.cfg
with the correct
revision in the root folder and whether the configuration file should be used. In case not
default settings are loaded.
•
the logger settings are adjusted according to the parameters set by the configuration and the
amplifiers are set regarding high voltage levels and thresholds.
•the logger scans for environmental sensors.
•
the logger checks the real time clock (RTC). In case of support battery failure the RTC is set to
a standard date and can update itself via GPS.
•in case a GSM module is used, it is activated and its bootup involves the following steps
–initializing of the modem: reset and restart,
–check for a SIM card
–check for signal availability (this requires an external antenna),
–connecting to the access point of the provider,
–check for signal quality.
If any of these steps fail the modem is shut off.
5
On the status display the sensor start procedure iterates through the following panels:
Step 1 Step 2 Step 3 Step 4
Step 5a 6a Step 5b Step 6b
Independently from the logger boot process the nCatcher is initialized with the following steps:
•the microcontroller initializes the internal and external I2C bus,
•
in case successful the connection to nCatcher channel 0 (
0x08
) or channel 1 (
0x09
) is displayed,
•hardware thresholds are adjusted,
•the high voltage (HV) is set.
The values for high voltage and threshold are stored in the internal non-volatile memory (EEPROM).
During the bootup process of the nCatcher these settings are loaded primarily. After that they can
be adjusted by the logger.
2.1.3 Sensor operation
On the status display after booting the following information are presented:
Main Panel - Events Main Panel - count rate
The uppermost two rows show the current logger temperature and relative humidity. The panel
switches in the lowest row between event information and count rate. Both numbers in the event
view are pulse height and pulse length of the last raw data obtained from the nCatcher unit. These
numbers should approximately lie in the range 100
. . .
400. Series of too high or too low values in-
dicate sensor malfunction. The count rate is calculated every 10 s and starts at a value of 0.0. As
the nCatcher operates independently from the logger, it already starts recording events before the
bootup process of the logger is finished. For this reason the first count rate value can be overestimated.
The logger operates in cycles of 1 s in normal mode and 10 s or more in the low-power mode. The
duration of one cycle is not fixed. It can be extended by various operations like a data transfer. The
system time is however obtained from a real time clock and therefore provides a correct measurement
of time. The cycle unit is used for an indirect measurement for adjusting intervals, such as
•
the number of cycles for averaging values of environmental sensors before storing them to the
SD card.
6
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