quaesta instruments tucson arizona founded in 2008 staff: 10 electronic devices: radiation detection...

Quaesta Instruments

• Tucson Arizona• Founded in 2008• Staff: 10• Electronic devices:

• radiation detection• environmental monitoring• data logging• telemetry

• Off-the-shelf and custom products

• Neutron Pulse Monitors- Proportional gas detectors

• Data logging devices

• Environmental sensors

• Mobile neutron detectors

• Soil moisture monitoring stations (radiation based)

Products

Neutron Pulse MonitorNPM

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

LowerDiscriminator

UpperDiscriminator

Multichannel Analyzer

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)

PeakValley

Real Spectra

0 20 40 60 80 100 120 1400

500

1000

1500

2000

2500BF3 Gas Proportional Tube,

Pulse Height Spectrum

Relative Pulse Height

# of

Cts

"Valley"

Wall-Effect Continuum

Gamma and Electronic Noise Generated Counts

Excited State Peak

Ground State Peak

Real Spectra

0 20 40 60 80 100 120 1400

500

1000

1500

2000

2500

3000

3500 Boron-Lined GE Reuter-Stokes TubePulse Height Spectrum

Relative Pulse Height

# of

Cts

Lithium-7 Recoil Events Alpha particle Events

Real Spectra

0 20 40 60 80 100 120 1400

50

100

150

200

250

300

He3 Tube Hgms indicated detecor problem during system QA testing. The manu-facturer reworked the tube.

Hgm # 0, 8/10/2011,04:47

Hgm # 1, 8/10/2011,05:12

Hgm # 2, 8/10/2011,06:12

Hgm # 3, 8/10/2011,07:12

Hgm # 4, 8/10/2011,08:12

Hgm # 5, 8/10/2011,09:12

Hgm # 6, 8/10/2011,10:12

Hgm # 7, 8/10/2011,11:12

Relative Pulse Height

# of

Cts

, Sca

led

He3 tube failure under thermal cycle testing

Example of Field Neutron Detector System Failure, BF3 DetectorTime Series

85 87 89 91 93 95 970

200

400

600

800

1000

1200

Customer Supplied Data, BF3 Detector, Deployed in Remote Field Location, Data Telemetry

via Iridium Satellite

Thermal Neutrons

Day of Year, 2011, UTC

Cts

/ H

r

0 20 40 60 80 100 120 1400

50

100

150

200

250

300

Customer Supplied Data, BF3 Detector, Remote Location, Data Telemetry via Iridium Satellite,

Hgms from Days 87 and 88 -> System OK!

Day 87Day 88

Relative Pulse Height

# of

Cts

(Sca

led)

Histograms before and after suspicious neutron counts

0 20 40 60 80 100 120 1400

50

100

150

200

250

300

Customer Supplied Data, BF3 Detector, Remote Location, Data Telemetry via Iridium Satellite,

Hgms from Days 91 and 92 -> System Problem!

Day 91

Day 92

Relative Pulse Height

# of

Cts

(Sca

led)

DirtyConnector

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

0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.70

50

100

150

200

250

300

350

400

0

10

20

30

40

50

60

70Univ of Arizona, He3 Roving Instrument, Channel 2 Humidity Intrusion

N1CN2CDeg CInstrument Relative Humidty %

Day of Month (Jul 2013)

Coun

ts p

er 1

min

ute

Inte

rval

Tem

pera

ture

and

RH%

Roving Detector Data

0 20 40 60 80 100 120 1400

50

100

150

200

250

300Univ of Arizona, He3 Roving Instrument, Channel 2, Humidity Intrusion

Before Humidity Intrusion, System OK

During Humidity Intrusion

After Humidity Intrusion, System Recovered

Relative Pulse Height

Scal

ed #

of C

ount

sRoving Detector Data

Noise produced by humidity

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

600 meters

Field scale soil moisture monitoring using cosmic ray neutrons

Measures fast and slow neutrons

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