1. WARAPORN NUNTIYAKUL 5238713 SCPY/D
Analysis of Data from a Calibration Neutron Monitor at Doi Inthanon and a Ship-Borne Neutron Monitor
Thesis Proposal
August 24, 2011
WARAPORN NUNTIYAKUL SCPY/D

2. OUTLINE 2 INTRODUCTION OBJECTIVES EXPECTED ADVANTAGES
METHODOLOGY AND SCOPE
RESEARCH PLANNING
ACKNOWLEDGEMENTS
REFERENCES

3. WHAT IS A NEUTRON MONITOR (NM)?
1. INTRODUCTION…
WHAT IS A NEUTRON MONITOR (NM)?
Neutron Monitor (NM) is a ground-based detector designed to measure the number of high-energy charged particles striking the Earth's atmosphere from outer space.
Developed to
IGY Monitor
Standard NM64 (1964)
(International Geophysical Year)
Design by Hatton and Carmichael
Design by Simpson (1948)
The efficiency of neutron counters to
record evaporation neutrons produced in
The lead of a monitor increased from
1.9% for the IGY to 5.7% for the NM64,
an increase of 3.3 times the counting rate
per unit area of lead producer.

4. Image Credit: PSNM station at Doi Inthanon,
1. INTRODUCTION…
CHARACTERISTIC OF NEUTRON MONITOR
A large instrument, weighing
32 tons
(18 tube NM64 is “supermonitor”)
Detects secondary neutrons
generated by collision of primary
cosmic rays with air molecules.
BARE
NM64
Image Credit: PSNM station at Doi Inthanon,
Chiang Mai, Thailand
Detection Method:
Older type-proportional counter
filled with BF3: n + 10B   + 7Li
Newer type-proportional counter
filled with 3He: n + 3He  p + 3H

5. NEUTRON MONITOR PRINCIPLE
1. INTRODUCTION…
NEUTRON MONITOR PRINCIPLE 5
An incoming hadron interacts with
a nucleus of lead to produce several
low energy neutrons.
These neutrons thermalize in
polyethylene or other material
containing a lot of hydrogen
Thermal neutrons cause fission
reaction in a 10B (7Li +4He) or
3He (3H + p) gas proportional counter.
The large amount of energy released
in the fission process dominates that
of all penetrating charged particles.
There is essentially no background.
Image Credit : Paul Evenson, January 2009

6. WHAT ARE THE RIGIDITY AND CUTOFF RIGIDITY ?
1. INTRODUCTION…
WHAT ARE THE RIGIDITY AND CUTOFF RIGIDITY ?
Rigidity; P is a concept used to determine the effect of particular magnetic fields on the motion of the charged particles. It is defined as
P  = B ρ  = p/q
Rigidity
Magnetic field
Gyroradius of particle
Momentum
Charge
Note: gyration depends on pitch angle
Geomagnetic cutoff rigidity; Pc are a quantitative measure of the shielding provided by the earth’s magnetic field, was estimated from
Early period: geomagnetic-dipole moment
Later period: the effect of the higher-order terms of the magnetic field
Final period: numerical calculation of cosmic-ray orbits in the geomagnetic field

7. Galactic cosmic ray spectrum Differential Response fn.
1. INTRODUCTION…
14/04/60
NEUTRON MONITOR LATITUDE SURVEYS
Transportable Monitor
(not to scale)
Galactic cosmic ray spectrum
heliospheric Modulation
geomagnetic Transmission
Scientific Background
Yield function
Counting Rate
Assuming T as a box function, L is a limiting rigidity as a numerical convenience
Differential Response fn.

8. THE WORLDWIDE NETWORK OF NM
1. INTRODUCTION…
THE WORLDWIDE NETWORK OF NM
Doi Inthanon
Image Credit :

9. WHY USE A CALIBRATION NM?
1. INTRODUCTION…
WHY USE A CALIBRATION NM?
TO DERIVE DIFFERENTIAL RESPONSE FUNC. OR ENERGY SPECTRA
dN/dP = differential response fn.
Pc1 = cutoff rigidity at location 1
Pc1 = cutoff rigidity at location 2
N(Pc1) = count rate at Pc1
N(Pc2) = count rate at Pc2
Moraal et al. (2000)
Fig 1. Example of expected differential response function for 11 inter-calibrated neutron monitors.

10. WHAT IS A CALIBRATION NM?
1. INTRODUCTION…
14/04/60
WHAT IS A CALIBRATION NM?
The name of Calibrator is “CALMON”
a = LND25382, 51 mm in diameter c = lead producer with diameters 101 and 193 mm
b = polyethylene(PE) moderator with inner d = reflector with diameters and mm
and outer diameters of and mm

11. Image Credit: PSNM station at Doi Inthanon,
1. INTRODUCTION
WHAT THE SYSTEM RECORDS ?
COUNTS
BAROMETRIC PRESSURE
HIGH VOLTAGE
TEMPERATURE
GPS CO-ORDINATES
GPS ALTITUDE
Image Credit: PSNM station at Doi Inthanon,
Chiang Mai, Thailand

12. The residual uncertainties in the intercalibration are mainly due to
2. OBJECTIVES
2.1 To compare count rates of the calibration monitor under various conditions.
The residual uncertainties in the intercalibration are mainly due to
(a) Different responses to primary intensity variations of NM of
different design.
(b) Different atmospheric (pressure and temperature) responses of the monitors.
(c) Environmental differences due to the fact that the calibrator can usually not be transported to the identical environment of the stationary neutron monitor.
Moraal et al. (2000)
The calibration accuracy of Neutron Monitors needs to be within 0.2%.
2.2 To determine the best method to characterize the evolution of the cosmic ray spectrum using data from the series of latitude surveys conducted from through 2007.

13. Calibration Procedure Ability to compare the cosmic ray intensity at
3. EXPECTED ADVANTAGES
Calibration Procedure
Ability to compare the cosmic ray intensity at
any two sites with different cutoff rigidity and
atmospheric depth.
Latitude Surveys
Derive useful differential response functions from the neutron monitor network.
Develop optimal methods for extracting cosmic
ray spectra from latitude surveys
Provide correct information on how the solar cycle affects cosmic rays.

14. 4.1 THE CALIBRATION PROCEDURE AT PSNM STATION
4. METHODOLOGY AND SCOPE…
4.1 THE CALIBRATION PROCEDURE AT PSNM STATION
PRINCESS SIRINDHORN
NEUTRON MONITOR
Location:
At Doi Inthanon ,
Chiang Mai, Thailand.
Design:
BP28-NM64
Altitude: 2,565 m above sea level
Geographic Coordinates:
18.59 ๐ North
98.49 ๐ East
Vertical cutoff rigidity: GV at Chiang Mai
Standard Pressure:
hPa (563 mmHg)
Barometric Coefficient:
-0.623%/hPa (-0.83%/mmHg)

15. Image Credit: PSNM station at Doi Inthanon,
4. METHODOLOGY AND SCOPE…
PRINCESS SIRINDHORN NEUTRON MONITOR
SET UP THE CALIBRATION NEUTRON MONITOR
Original PSNM Station
Modified PSNM Station (April 2010)
ELECTRONICS HEAD
Image Credit: PSNM station at Doi Inthanon,
Chiang Mai, Thailand
from POTCHEFSTROOM CAMPUS NORTH - WEST UNIVERSITY, SA
from BARTOL RESEARCH INSTITUTE
UNIVERSITY OF DELAWARE, USA

16. 4. METHODOLOGY AND SCOPE… 16
14/04/60
Test for stability and repeatability of the Calibrator with eliminating of environmental effects.
Table configurations of the calibration procedure
The Calmon data were put on the Doi Inthanon FTP. The URL is ftp:// /CalmonData/

17. 4. METHODOLOGY AND SCOPE… 17
Krüger et al. (2010)
Fig 2. The ratio of the count rates of the IGY and calibration neutron monitor as function of the height of the calibration neutron monitor above a concrete Floor, with different amounts of water and brick underneath the calibrator.

18. 4. METHODOLOGY AND SCOPE… 18
Determine a normalization factor for the count rate of the stationary neutron monitor relative to the others in the world-wide network.
Doi Inthanon

19. 4. METHODOLOGY AND SCOPE… 19
Preliminary Results report in International Cosmic Ray Conference (ICRC), Beijing 2011
1st experiment
Performed in Potchefstroom, SA
2nd experiment
Performed in Kiel, GE
[from March to May, 2008]
3rd experiment
Performed in Doi Inthanon, TH
[from Nov, 2009 to Jun, 2010]
Decrease 1.56%
[Doi Inthanon 140 cm]
Decrease  4.0%
[Potchefstroom]
Decrease  4.2%
[Doi Inthanon 70 cm]
The counting decreases with an increase in the amount of water, and the counting rate levels off when the water level  30 cm
Fig 3. The ratio of the count rates of the Potchefstroom NM (open circles) and the NM at Doi Inthanon as
Function of varying heights of water beneath the calibrator.

20. 4. METHODOLOGY AND SCOPE… 20
Determine the ratio of efficiency of the two NMs.
To quantify the calibration process, consider two NMs at different cutoff rigidities and altitudes, with different efficiencies (due to difference in type of neutron monitor, number of counters, and different environment). Suppose NM1 is calibrated against the calibrator at time t1, and similarly NM2 at time t2.
Then we have the following five measurements:
At time t1 the counting rate (cr.) of NM1 is N1,1
At time t2 the cr. of NM1 is N1,2
At time t2 the cr. of NM2 is N2,2
At t1 the cr. of the calibrator at NM1 is C1,1
At t2 the cr. of the calibrator at NM2 is C2,2
At time t2 the counting rate of the calibrator at NM1 can then be calculated as C1,2 = (N1,2/N1,1)*C1,1. NM
calibrator
calculation
measurement
The measured ratio of the two NMs at time t2
The measured ratio of the calibrator counts at the two positions.

21. 4. METHODOLOGY AND SCOPE… 21
Preliminary Results report in International Cosmic Ray Conference (ICRC), Beijing 2011
Table 2. Hourly counting rates during the calibrations
Table 3. Characteristics, barometric coefficient, and efficiency ratio of each NM relative to the Potchefstroom NM.

22. 4. METHODOLOGY AND SCOPE… 22
4.2 ANALYZE THE DATA FROM A SHIP-BORNE MONITOR WITH THREE COUNTER TUBES.
Made trips across the Pacific ocean from Seattle to Antarctica and back, over a wide range of cutoff rigidities, over to
U.S. Coast Guard icebreakers, the Polar Sea or the Polar Star
carry a Neutron monitor standard 3-NM64
U.S. Coast Guard icebreakers
Fig 4.

23. … … 4. METHODOLOGY AND SCOPE… 23
Download and analyze the latitude survey data.
The latitude survey data were put on the Bartol FTP. The URL is as follows:
ftp://ftp.bartol.udel.edu/pyle/OtherData/LatSurvSegments/
Bieber et al. (2003)
Part of the listing: …
A: S(eattle)-C(utoff)E(quator)
B: CE - M(cMurdo)
C: M - CE
D: CE - S.
The format is as follows:
YY/MM/DD HH:MM:SS Vcutoff Rate Rate2 …
Fig 5. Sample fit of a segment’s data to a Dorman function, along with the corresponding derivative
Latitude or Longitude changed by greater than degrees during the hour (>0.14 miles/hour)

24. 4. METHODOLOGY AND SCOPE… 24
Characterize Cosmic Ray Spectra. [Nagashima et al (1989)]
Yield Function
- This term is due to the energy dependence of the neutron production and expresses the x-dependence of Y in high-energy region
- This term expresses the decrease of the production mainly due to the decrease of the number of effective nucleons in the atmosphere with the increase of x and with the decrease of u
u = U/U0
U = the total energy
U0 = the rest energy
x = pressure in mbar
(atmospheric depth)
Fig 6. Data (left) and model fit (Right) to the moderated neutron detector latitude survey.

25. 4. METHODOLOGY AND SCOPE
Fig 7. Residuals (counts/second) from the fit shown in Figure 6 as a function of geomagnetic cutoff.

26. 5. RESEARCH PLANNING 26 Number Details Time period Month 1.
Theoretical study and reviews
6 months
November 2010-May 2011 2.
Data analysis
9 months
May 2011-Febuary 2012 3.
Data characterization and synthesizing existing and/ or new concepts
8 months
October June 2012 4.
Interpretation
June 2012-March 2013 5.
Writing thesis
March 2013-September 2013

27. 6. ACKNOWLEDGEMENTS 27 Prof. David Ruffolo Prof. Paul Evenson
RGJ Scholarship
PSNM
Mahidol U.
Prof. David Ruffolo
Prof. Paul Evenson
Dr. Alejandro Sáiz
Space Physics and Energetic Particles Group

28. 7. REFERENCES…
Bieber, J.W., and Evenson, P. (1995), Spaceship Earth – an Optimized Network of Neutron Monitors, Proc. 24th International Cosmic Ray Conference (Rome) 4,
Bieber, J.W., Evenson, P., Humble, J.E., and Duldig, M.L. (1997), Cosmic Ray Spectra Deduced from Neutron Monitor Surveys, Proc. 25th International Cosmic Ray Conference (Durban) 2,
Bieber, J.W., Clem, J., and Evenson, P. (1997), Efficient computation of apparent cutoffs, Proc. 25th International Cosmic Ray Conference (Durban) 2,
Bieber, J.W., Clem, J., Duldig, M.L., Evenson, P., Humble, J.E., and Pyle, R. (2001), A continuing yearly neutron monitor latitude survey: Preliminary results from , Proc. 27th International Cosmic Ray Conference (Hamburg) 10,
Bieber, J.W., Clem, J., Duldig, M.L., Evenson, P., Humble, J.E., and Pyle, R. (2001), New method of observing neutron monitor multiplicities, Proc. 27th International Cosmic Ray Conference (Hamburg) 10,
Bieber, J.W., Clem, J.M., Duldig, M.L., Evenson, P.A., Humble, J.E., Pyle, R. (2003), Cosmic Ray Spectra and the Solar Magnetic Polarity: Preliminary Results from , Solar Wind Ten: Proceedings of the Tenth International Solar Wind Conference, Pisa, Italy, AIP Conference Proceedings. 679,

29. 7. REFERENCES…
Bieber, J.W., Clem, J.M., Duldig, M.L., Evenson, P., Humble, J.E., Pyle, R. (2004), Latitude survey observations of neutron monitor multiplicity, JGR. 109, A12106.
Clem, J.M., David P. Clements, Joseph Esposito, Evenson P., David H., and Jacques L’Heureux (1996), Solar modulation of cosmic electrons, APJ. 464,
Clem, J.M., Bieber, J.W., and Evenson P. (1997), Contribution of obliquely incident particles to neutron monitor counting rate, J. Geophys. Res. 102,
Clem, J.M. (1999), Atmospheric yield functions and the response to secondary particles of neutron monitors, Proc. 26th International Cosmic Ray Conference (Salt Lake City) 7,
Clem, J.M., and Dorman, L.I. (2000), Neutron Monitor Response Functions, Space Sci. Rev. 93,
Dorman, L.I., Villoresi, G., Iucci, N., Parisi, M., Parisi, M.I., Tyasto, O.A., Danilova, A., and Ptitsyna, N.G. (2000), Cosmic ray survey to Antarctica and coupling functions for neutron component near solar minimum ( ): Geomagnetic effects and coupling functions, J. Geophys. Res. 105, 21,047.

30. 7. REFERENCES…
Evenson, P., Bieber, J.W., Clem, J., and Pyle, R. (2005), Neutron monitor temperature coefficients: measurements for BF3 and 3He Counter tubes, Proc. 29th International Cosmic Ray Conference (Pune) 2,
Hatton, C.J., and Carmichael, H. (1964), Experimental investigation of the NM-64 neutron monitor, Can. J. Phys. 42,
Hatton, C.J. (1971), The Neutron Monitor, in Progress in Elementary Particle and Cosmic Ray Physics X, Ed. J.G. Wilson and S.A. Wouthuysen, North Holland Publishing Co., Amsterdam.
Hess, W.N., Patterson, H.W., and Wallace, R. (1959), Cosmic Ray Neutron Energy Spectrum, Phys. Rev. 116,
Krüger, H., Moraal, H., Bieber, J.W., Clem, J.M., Evenson, P., Pyle, K.R., Duldig, M.L., and Humble, J.E. (2003), First Results of a Mobile Neutron Monitor to Intercalibrate the Worldwide Network, Proc. 28th International Cosmic Ray Conference (Tsukuba) 6,
Krüger, H., Moraal, H., Bieber, J.W., Clem, J.M., Evenson, P., Pyle, K.R., Duldig, M.L., and Humble, J.E. (2005), Latitude surveys with a calibration neutron monitor, Proc. 29th International Cosmic Ray Conference (Pune) 2,
Krüger, H. (2006), A calibration neutron monitor for long-term cosmic ray modulation studies, Ph.D. thesis, North-West Univ., Potchefstroom, South Africa.

31. 7. REFERENCES…
Krüger, H., Moraal, H., Bieber, J.W., Clem, J.M., Evenson, P., Pyle, K.R., Duldig, M.L., and Humble, J.E. (2007), Experiments with two calibration neutron monitors, Proc. 30th International Cosmic Ray Conference (Mérida). 1,
Krüger, H., Moraal, H., Bieber, J.W., Clem, J.M., Evenson, P., Pyle, K.R., Duldig, M.L., and Humble, J.E. (2008), A calibration neutron monitor: Energy response and instrumental temperature sensitivity, J. Geophys. Res. 113, A08101, 6pp., doi: /2008JA
Krüger, H., Moraal, H. (2010), A calibration neutron monitor: Statistical accuracy and environmental sensitivity, ADV. Space. Res. 46,
Lumme, M., Nieminen, M., Peltonen, J., Torsti, J.J., Vainikka, E., and Valtonen, E. (1983a), Multiplicity Response Function of the Double Neutron Monitor at Turku, Proc. 18th International Cosmic Ray Conference (Bagelore) 3,
Mischke, C.F.W., Stoker, P.H., and Duvenage, J. (1973), The Neutron Moderated Detector and the Determination of Rigidity Dependence of Protons From the ½ September Solar Flare, Proc. 13th International Cosmic Ray Conference (Denver) 2,
Moraal, H., Potgieter, M.S., Stoker, P.H., and van der Walt, A.J. (1989), Neutron Monitor Latitude Survey of the Cosmic Ray Intensity During the 1986/87 Solar Minimum, J. Geophys. Res. 94,

32. 7. REFERENCES…
Moraal, H., Belov, A., and Clem, J.M. (2000), Design and co-ordination of multi-station international neutron monitor networks, Space Sci. Rev. 93,
Moraal, H., Benadie, A., de Villiers, D., Bieber, J.W., Clem, J.M., Evenson P., Pyle, K.R., Shulman, L., Duldig, M.L., and Humble, J.E. (2001), A mobile neutron monitor to intercalibrate the worldwide network, Proc. 27th International Cosmic Ray Conference (Hamburg) 8,
Moraal, H., Krüger, H., Benadie, A., De Villiers, D. (2003), Calibration of the Sanae and Hermanus neutron monitors, Proc. 28th International Cosmic Ray Conference (Tsukuba) 7,
Pyle, R., Evenson, P., Bieber, J.W., Clem, J.W., Humble, J.E., and Duldig, M.L. (1999), The Use of 3He tubes in a Neutron Monitor Latitude Survey, Proc. 26th International Cosmic Ray Conference (Salt Lake City) 7,
Raubenheimer, B.C., and Stoker, P.H. (1974), Attenuation Coefficient of a Neutron Monitor, J. Geophys. Res. 79,
Sáiz, A., Ruffolo, D., Rujiwarodom, M., Bieber, J.W., Clem, J., Evenson, P., Pyle, R., Duldig, M.L., Humble, J.E. (2005), Relativistic Particle Injection and Interplanetary Transport during the January 20, Proc. 29th International Cosmic Ray Conference (Pune) 1,

33. 7. REFERENCES
Simpson, J.A. (1948), The Latitude Dependence of Neutron Densities in the Atmosphere as a Function of Altitude, Phys. Rev. 73, 389–395.
Stoker, P.H. (1981), Primary Spectral Variations of Cosmic Rays Above 1 GV, th International Cosmic Ray Conference (Paris) 3,
Stoker, P.H., and Moraal, H. (1995), Neutron Monitor Latitude Surveys at Aircraft Altitudes, Astrophys. Space Sci. 230,
Stoker, P.H., Dorman, L.I., and Clem, J.M. (2000), Neutron motitor design improvements, Space Sci. Rev. 93,
Usoskin, I.G., Kovaltsov, G.A., Kananen, H., and Tanskanen, P. (1997), The World Neutron Monitor Network as a Tool for the Study of Solar Neutrons, Ann. Geophysicae, 15,

34. EFFECTIVE CUTOFF RIGIDITY SKY MAP…
8. SUPPORT SLIDES
EFFECTIVE CUTOFF RIGIDITY SKY MAP…
Image Credit: Clem et al. (1997)
Apparent Cutoff is a new method for calculating geomagnetic cutoffs that incorporates obliquely incident primaries, using it to interpret a sea level neutron monitor latitude survey.
Stoker (1995) suggested that oblique particles might also be responsible for anomalies in neutron monitor latitude surveys.

35. EFFECTIVE CUTOFF RIGIDITY SKY MAP
8. SUPPORT SLIDES
EFFECTIVE CUTOFF RIGIDITY SKY MAP
Image Credit: Clem et al. (1997)

36. RESULT EFF. VERTICAL & APPARENT CUTOFF (GV)
8. SUPPORT SLIDES
RESULT EFF. VERTICAL & APPARENT CUTOFF (GV)
Image Credit: Clem et al. (1997)

37. NOTE OF 15 CONFIGURATIONS
8. SUPPORT SLIDES
NOTE OF 15 CONFIGURATIONS

38. RESULT OF KRUGER (2010) 8. SUPPORT SLIDES 38
3.5% decrease in the count rate, reaching a minimum for an amount of 30 g/cm2 of
moderator/absorber.
The decrease in the count rate with an increase in the amount of water beneath the calibrator is 5.3%, with the saturation point at 20.
The count rate decreased by 3.8%, but it saturated again at 20 cm.
Krüger et al. (2010)
Fig 3. (a) The ratio of the count rates of the Pochefstroom neutron monitor (IGY) and Calibrator as function of thickness of absorbing material underneath the calibrator, with the calibrator in an enclosed building. The calibrator was kept at a fixed height of 40 cm above the floor. (b) The same ratio as function of height on the open roof of building, while the calibrator was kept immediately above the water level;
(c) a repetition of (b) on ground level far removed from any building.

39. SPECTRAL CROSSOVER 8. SUPPORT SLIDES 39
Rigidity P (GV)
Pairs of response functions at 11 and 22 year intervals illustrate the “spectral crossover” effect

40. How to analyze CALMON data in each configuration…
8. SUPPORT SLIDES
How to analyze CALMON data in each configuration…
Dowload the data from ftp:// /CalmonData/
2. Calculate the values of fracDOY, Count/hour, N, Tave, pave
File name: secselhour

41. How to analyze CALMON data in each configuration…
8. SUPPORT SLIDES
How to analyze CALMON data in each configuration…
3. Check and analyze the data
Fig 1

42. How to analyze CALMON data in each configuration…
8. SUPPORT SLIDES
How to analyze CALMON data in each configuration…
Fig 2

43. How to analyze CALMON data in each configuration…
8. SUPPORT SLIDES
How to analyze CALMON data in each configuration…
Fig 3

44. How to analyze CALMON data in each configuration…
8. SUPPORT SLIDES
How to analyze CALMON data in each configuration…
Fig 4

45. How to analyze CALMON data in each configuration…
8. SUPPORT SLIDES
How to analyze CALMON data in each configuration…
Fig 5

46. How to analyze CALMON data in each configuration…
8. SUPPORT SLIDES
How to analyze CALMON data in each configuration…
Fig 6

47. How to analyze CALMON data in each configuration…
8. SUPPORT SLIDES
How to analyze CALMON data in each configuration…
Fig 7