Presentation on theme: "WARAPORN NUNTIYAKUL SCPY/D"— Presentation transcript:
1WARAPORN NUNTIYAKUL 5238713 SCPY/D Analysis of Data from a Calibration Neutron Monitor at Doi Inthanon and a Ship-Borne Neutron MonitorThesis ProposalAugust 24, 2011WARAPORN NUNTIYAKUL SCPY/D
2OUTLINE 2 INTRODUCTION OBJECTIVES EXPECTED ADVANTAGES METHODOLOGY AND SCOPERESEARCH PLANNINGACKNOWLEDGEMENTSREFERENCES
3WHAT 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 toIGY MonitorStandard NM64 (1964)(International Geophysical Year)Design by Hatton and CarmichaelDesign by Simpson (1948)The efficiency of neutron counters torecord evaporation neutrons produced inThe lead of a monitor increased from1.9% for the IGY to 5.7% for the NM64,an increase of 3.3 times the counting rateper unit area of lead producer.
4Image Credit: PSNM station at Doi Inthanon, 1. INTRODUCTION…CHARACTERISTIC OF NEUTRON MONITORA large instrument, weighing32 tons(18 tube NM64 is “supermonitor”)Detects secondary neutronsgenerated by collision of primarycosmic rays with air molecules.BARENM64Image Credit: PSNM station at Doi Inthanon,Chiang Mai, ThailandDetection Method:Older type-proportional counterfilled with BF3: n + 10B + 7LiNewer type-proportional counterfilled with 3He: n + 3He p + 3H
5NEUTRON MONITOR PRINCIPLE 1. INTRODUCTION…NEUTRON MONITOR PRINCIPLE5An incoming hadron interacts witha nucleus of lead to produce severallow energy neutrons.These neutrons thermalize inpolyethylene or other materialcontaining a lot of hydrogenThermal neutrons cause fissionreaction in a 10B (7Li +4He) or3He (3H + p) gas proportional counter.The large amount of energy releasedin the fission process dominates thatof all penetrating charged particles.There is essentially no background.Image Credit : Paul Evenson, January 2009
6WHAT 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 asP = B ρ = p/qRigidityMagnetic fieldGyroradius of particleMomentumChargeNote: gyration depends on pitch angleGeomagnetic cutoff rigidity; Pc are a quantitative measure of the shielding provided by the earth’s magnetic field, was estimated fromEarly period: geomagnetic-dipole momentLater period: the effect of the higher-order terms of the magnetic fieldFinal period: numerical calculation of cosmic-ray orbits in the geomagnetic field
7Galactic cosmic ray spectrum Differential Response fn. 1. INTRODUCTION…14/04/60NEUTRON MONITOR LATITUDE SURVEYSTransportable Monitor(not to scale)Galactic cosmic ray spectrumheliospheric Modulationgeomagnetic TransmissionScientific BackgroundYield functionCounting RateAssuming T as a box function, L is a limiting rigidity as a numerical convenienceDifferential Response fn.
8THE WORLDWIDE NETWORK OF NM 1. INTRODUCTION…THE WORLDWIDE NETWORK OF NMDoi InthanonImage Credit :
9WHY USE A CALIBRATION NM? 1. INTRODUCTION…WHY USE A CALIBRATION NM?TO DERIVE DIFFERENTIAL RESPONSE FUNC. OR ENERGY SPECTRAdN/dP = differential response fn.Pc1 = cutoff rigidity at location 1Pc1 = cutoff rigidity at location 2N(Pc1) = count rate at Pc1N(Pc2) = count rate at Pc2Moraal et al. (2000)Fig 1. Example of expected differential response function for 11 inter-calibrated neutron monitors.
10WHAT IS A CALIBRATION NM? 1. INTRODUCTION…14/04/60WHAT IS A CALIBRATION NM?The name of Calibrator is “CALMON”a = LND25382, 51 mm in diameter c = lead producer with diameters 101 and 193 mmb = polyethylene(PE) moderator with inner d = reflector with diameters and mmand outer diameters of and mm
11Image Credit: PSNM station at Doi Inthanon, 1. INTRODUCTIONWHAT THE SYSTEM RECORDS ?COUNTSBAROMETRIC PRESSUREHIGH VOLTAGETEMPERATUREGPS CO-ORDINATESGPS ALTITUDEImage Credit: PSNM station at Doi Inthanon,Chiang Mai, Thailand
12The residual uncertainties in the intercalibration are mainly due to 2. OBJECTIVES2.1 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 ofdifferent 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.
13Calibration Procedure Ability to compare the cosmic ray intensity at 3. EXPECTED ADVANTAGESCalibration ProcedureAbility to compare the cosmic ray intensity atany two sites with different cutoff rigidity andatmospheric depth.Latitude SurveysDerive useful differential response functions from the neutron monitor network.Develop optimal methods for extracting cosmicray spectra from latitude surveysProvide correct information on how the solar cycle affects cosmic rays.
144.1 THE CALIBRATION PROCEDURE AT PSNM STATION 4. METHODOLOGY AND SCOPE…4.1 THE CALIBRATION PROCEDURE AT PSNM STATIONPRINCESS SIRINDHORNNEUTRON MONITORLocation:At Doi Inthanon ,Chiang Mai, Thailand.Design:BP28-NM64Altitude: 2,565 m above sea levelGeographic Coordinates:18.59 ๐ North98.49 ๐ EastVertical cutoff rigidity: GV at Chiang MaiStandard Pressure:hPa (563 mmHg)Barometric Coefficient:-0.623%/hPa (-0.83%/mmHg)
15Image Credit: PSNM station at Doi Inthanon, 4. METHODOLOGY AND SCOPE…PRINCESS SIRINDHORN NEUTRON MONITORSET UP THE CALIBRATION NEUTRON MONITOROriginal PSNM StationModified PSNM Station (April 2010)ELECTRONICS HEADImage Credit: PSNM station at Doi Inthanon,Chiang Mai, Thailandfrom POTCHEFSTROOM CAMPUS NORTH - WEST UNIVERSITY, SAfrom BARTOL RESEARCH INSTITUTEUNIVERSITY OF DELAWARE, USA
164. METHODOLOGY AND SCOPE… 16 14/04/60Test for stability and repeatability of the Calibrator with eliminating of environmental effects.Table configurations of the calibration procedureThe Calmon data were put on the Doi Inthanon FTP. The URL is ftp:// /CalmonData/
174. 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.
184. 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
194. METHODOLOGY AND SCOPE… 19 Preliminary Results report in International Cosmic Ray Conference (ICRC), Beijing 20111st experimentPerformed in Potchefstroom, SA2nd experimentPerformed in Kiel, GE[from March to May, 2008]3rd experimentPerformed 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 cmFig 3. The ratio of the count rates of the Potchefstroom NM (open circles) and the NM at Doi Inthanon asFunction of varying heights of water beneath the calibrator.
204. 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 N1,1At time t2 the cr. of NM1 is N1,2At time t2 the cr. of NM2 is N2,2At t1 the cr. of the calibrator at NM1 is C1,1At t2 the cr. of the calibrator at NM2 is C2,2At time t2 the counting rate of the calibrator at NM1 can then be calculated as C1,2 = (N1,2/N1,1)*C1,1.NMcalibratorcalculationmeasurementThe measured ratio of the two NMs at time t2The measured ratio of the calibrator counts at the two positions.
214. METHODOLOGY AND SCOPE… 21 Preliminary Results report in International Cosmic Ray Conference (ICRC), Beijing 2011Table 2. Hourly counting rates during the calibrationsTable 3. Characteristics, barometric coefficient, and efficiency ratio of each NM relative to the Potchefstroom NM.
224. 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 toU.S. Coast Guard icebreakers, the Polar Sea or the Polar Starcarry a Neutron monitor standard 3-NM64U.S. Coast Guard icebreakersFig 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 - CED: 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 derivativeLatitude or Longitude changed by greater than degrees during the hour (>0.14 miles/hour)
244. 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 uu = U/U0U = the total energyU0 = the rest energyx = pressure in mbar(atmospheric depth)Fig 6. Data (left) and model fit (Right) to the moderated neutron detector latitude survey.
254. METHODOLOGY AND SCOPEFig 7. Residuals (counts/second) from the fit shown in Figure 6 as a function of geomagnetic cutoff.
265. RESEARCH PLANNING 26 Number Details Time period Month 1. Theoretical study and reviews6 monthsNovember 2010-May 20112.Data analysis9 monthsMay 2011-Febuary 20123.Data characterization and synthesizing existing and/ or new concepts8 monthsOctober June 20124.InterpretationJune 2012-March 20135.Writing thesisMarch 2013-September 2013
276. ACKNOWLEDGEMENTS 27 Prof. David Ruffolo Prof. Paul Evenson RGJ ScholarshipPSNMMahidol U.Prof. David RuffoloProf. Paul EvensonDr. Alejandro SáizSpace Physics and Energetic Particles Group
287. 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,
297. 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.
307. 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.
317. 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: /2008JAKrüger, 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,
327. 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,
337. REFERENCESSimpson, 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,
34EFFECTIVE CUTOFF RIGIDITY SKY MAP… 8. SUPPORT SLIDESEFFECTIVE 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.
35EFFECTIVE CUTOFF RIGIDITY SKY MAP 8. SUPPORT SLIDESEFFECTIVE CUTOFF RIGIDITY SKY MAPImage Credit: Clem et al. (1997)
37NOTE OF 15 CONFIGURATIONS 8. SUPPORT SLIDESNOTE OF 15 CONFIGURATIONS
38RESULT OF KRUGER (2010) 8. SUPPORT SLIDES 38 3.5% decrease in the count rate, reaching a minimum for an amount of 30 g/cm2 ofmoderator/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.
39SPECTRAL CROSSOVER 8. SUPPORT SLIDES 39 Rigidity P (GV)Pairs of response functions at 11 and 22 year intervals illustrate the “spectral crossover” effect
40How to analyze CALMON data in each configuration… 8. SUPPORT SLIDESHow to analyze CALMON data in each configuration…Dowload the data from ftp:// /CalmonData/2. Calculate the values of fracDOY, Count/hour, N, Tave, paveFile name: secselhour
41How to analyze CALMON data in each configuration… 8. SUPPORT SLIDESHow to analyze CALMON data in each configuration…3. Check and analyze the dataFig 1
42How to analyze CALMON data in each configuration… 8. SUPPORT SLIDESHow to analyze CALMON data in each configuration…Fig 2
43How to analyze CALMON data in each configuration… 8. SUPPORT SLIDESHow to analyze CALMON data in each configuration…Fig 3
44How to analyze CALMON data in each configuration… 8. SUPPORT SLIDESHow to analyze CALMON data in each configuration…Fig 4
45How to analyze CALMON data in each configuration… 8. SUPPORT SLIDESHow to analyze CALMON data in each configuration…Fig 5
46How to analyze CALMON data in each configuration… 8. SUPPORT SLIDESHow to analyze CALMON data in each configuration…Fig 6
47How to analyze CALMON data in each configuration… 8. SUPPORT SLIDESHow to analyze CALMON data in each configuration…Fig 7