Transcript 01 Quaesta Instrumen..

Quaesta Instruments
•
•
•
•
Tucson Arizona
Founded in 2008
Staff: 10
Electronic devices:
• radiation detection
• environmental monitoring
• data logging
• telemetry
• Off-the-shelf and custom products
Products
• Neutron Pulse Monitors
-Proportional gas detectors
• Data logging devices
• Environmental sensors
• Mobile neutron detectors
• Soil moisture monitoring stations
(radiation based)
Neutron Pulse Monitor
NPM
Pulse Height Spectrum
Classical 3He spectrum digitized over 128 bins
Plateau Method
Counting Plateau
Lower
discriminator
Plateau Method
• Requires many points for good resolution on discriminator set point
• For low count rates, time per point may be large
Multichannel Analyzer
Lower
Discriminator
Upper
Discriminator
Setting the Discriminator Levels
With a Multichannel Analyzer (MCA)
Setting the Discriminator Levels
With a Multichannel Analyzer (MCA)
Setting the Discriminator Levels
With a Multichannel Analyzer (MCA)
Setting the Discriminator Levels
With a Multichannel Analyzer (MCA)
Setting the Discriminator Levels
With a Multichannel Analyzer (MCA)
Setting the Discriminator Levels
With a Multichannel Analyzer (MCA)
Setting the Discriminator Levels
With a Multichannel Analyzer (MCA)
Setting the Discriminator Levels
With a Multichannel Analyzer (MCA)
Setting the Discriminator Levels
With a Multichannel Analyzer (MCA)
Setting the Discriminator Levels
With a Multichannel Analyzer (MCA)
Setting the Discriminator Levels
With a Multichannel Analyzer (MCA)
Setting the Discriminator Levels
With a Multichannel Analyzer (MCA)
Valley
Peak
Setting the Discriminator Levels
With a Multichannel Analyzer (MCA)
Valley
Peak
Real Spectra
Real Spectra
BF3 Gas Proportional Tube,
Pulse Height Spectrum
2500
Excited State Peak
# of Cts
2000
Gamma and Electronic
Noise Generated
Counts
1500
1000
"Valley"
500
Wall-Effect
Continuum
Ground State Peak
0
0
20
40
60
Relative Pulse Height
80
100
120
140
Real Spectra
3500
Boron-Lined GE Reuter-Stokes Tube
Pulse Height Spectrum
3000
# of Cts
2500
2000
Lithium-7 Recoil Events
1500
Alpha particle Events
1000
500
0
0
20
40
60
80
Relative Pulse Height
100
120
140
He3 tube failure under thermal cycle testing
He3 Tube Hgms indicated detecor problem during system QA testing. The
manufacturer reworked the tube.
300
Hgm # 0, 8/10/2011,04:47
250
Hgm # 1, 8/10/2011,05:12
Hgm # 2, 8/10/2011,06:12
# of Cts, Scaled
200
Hgm # 3, 8/10/2011,07:12
150
Hgm # 4, 8/10/2011,08:12
Hgm # 5, 8/10/2011,09:12
100
Hgm # 6, 8/10/2011,10:12
50
Hgm # 7, 8/10/2011,11:12
0
0
20
40
60
Relative Pulse Height
80
100
120
140
Example of Field Neutron Detector System Failure, BF3 Detector
Time Series
Customer Supplied Data, BF3 Detector,
Deployed in Remote Field Location, Data Telemetry
via Iridium Satellite
1600
Thermal Neutrons
1400
1200
Cts/ Hr
1000
800
600
400
200
0
85
87
89
91
Day of Year, 2011, UTC
93
95
97
Histograms before and after suspicious neutron counts
Customer Supplied Data, BF3 Detector,
Remote Location, Data Telemetry via Iridium Satellite,
Hgms from Days 87 and 88 -> System OK!
300
200
Day 87
150
Day 88
100
50
0
0
20
40
60
80
100
120
140
Relative Pulse Height
300
Customer Supplied Data, BF3 Detector,
Remote Location, Data Telemetry via Iridium Satellite,
Hgms from Days 91 and 92 -> System Problem!
250
# of Cts (Scaled)
# of Cts (Scaled)
250
Day 91
200
Day 92
Dirty
Connector
150
100
50
0
0
20
40
60
80
Relative Pulse Height
100
120
140
NPM Architecture
Value of a Digital NPM
• Computer interface
• MCA & spectra - optimization
• Monitoring
• Data logging
Data Logger
•
•
•
•
•
•
•
Analog & digital I/Os
Relays
USB, RS-232, SDI-12
SD cards
Connect to NPMs
External Sensors
Telemetry
Remote Monitoring & Mobile Detectors
Remote Monitoring & Mobile Detectors
Remote Monitoring & Mobile Detectors
Roving Detector Data
Univ of Arizona, He3 Roving Instrument, Channel 2 Humidity Intrusion
N1C
N2C
Deg C
Instrument Relative Humidty %
350
300
70
60
50
250
40
200
30
150
20
100
50
10
0
0
0.0
0.1
0.2
0.3
0.4
Day of Month (Jul 2013)
0.5
0.6
0.7
Temperature and RH%
Counts per 1 minute Interval
400
Roving Detector Data
Univ of Arizona, He3 Roving Instrument, Channel 2, Humidity Intrusion
300
Before Humidity Intrusion, System OK
Scaled # of Counts
250
During Humidity Intrusion
200
After Humidity Intrusion, System Recovered
150
100
50
0
0
20
40
60
80
Relative Pulse Height
Noise produced by humidity
100
120
140
Remote Monitoring & Mobile Detectors
IAEA: Mobile Unit for Neutron Detection (MUNDs)
IAEA: MUNDs
NPM
NPM: Ethernet + 15MHz input pulse counter
Soil Moisture Monitoring
Average Soil Moisture
Field scale soil moisture monitoring using
cosmic ray neutrons
Measures fast and slow neutrons
600 meters
Pressure & Humidity dependent
Soil Moisture Monitoring
Challenges
• Low power consumption
• Very low count rate
• High stability in calibration
required wide temperature range
• High resolution pressure meas
Soil Moisture Monitoring
Soil Moisture Monitoring
Alpine Location
New Stuff
Neutron Detector Arrays
Neutron Detector Arrays