Angular Distribution of Cosmic Ray Muons

Investigators: Peter Karn

David Kearsley

Project Advisor: Phillip Dudero

http://mxp.physics.umn.edu/s07/Projects/S07_CosmicRaysDistribution/

Project Relevance & Applications

• Investigation of high-energy astrophysical processes.

• CR Damage to quantum-scale computer components (e.g. Josephson Junctions) and related devices.

• CR Effects on CCDs (Charge-Coupled Devices) used in astrophysics.

• CR Effects on telecommunications & spaceflight systems.

Sources of Cosmic Rays

• Short Timescale Solar Activity– Flares

• Stellar Processes– Supernova Nucleosynthesis– Neutron star core collapse

• Gamma Ray Bursts (GRB)

• Galactic Processes– Active Galactic Nuclei (AGN) jets

Compton Gamma Ray Observatory (GRO)

Cosmic Ray Shower Processes I

AIRES Cosmic Ray Shower Simulation of 1TeV incident proton (x = y = 5km, z = 20km), University of Chicago.

Cosmic Ray Shower Products (CERN).

x

y

z

Cosmic Ray Shower Processes II• Incident Particles

– Types: p, n, He, heavy nuclei– Energies: ~GeV ~100TeV

• Secondary Products– Types: p, – Energies: ~GeV

• End Products– Types: e, e, e,

– Energies: ~MeV ~GeV

Muons (0 = 2.2 10-6 sec) are observed to survive at sea-level due to Lorentz time dilation:

)/(1 22

00

cv

Angular Distribution

• 1st Order Approximation: 1. F(0) = F() 2. F(/2) = F(tangential)

• F() = F(0)cos2()1. F = particle flux in (N)(sec-1)(sr-1).2. N = Number of events.3. = Incident angle relative to zenith (= 0).4. Angular area is measured in steradians (sr),

such that, () = (1rad)(1rad).

KAKE Cosmic Ray Telescope I

• (D0) Coincidence Detector a.k.a. “PESTILENCE”

• (DM0) Zenith Measurement Detector a.k.a. “FAMINE”

• (DM1) Angular Distribution Measurement Detector a.k.a. “WAR”

Plastic ScintillatorLight-PipePMT

KAKE Cosmic Ray Telescope II• 3x Detectors• 3x 2kV Power

Supplies• 3x Discriminator

Channels:– 10ns pulses

• 2x2 Coincidence:– (DM0+D0)– (DM1+D0)

• Dual-Counter• NIM-TTL

Translator• PCI 6602 DAQC

D0 DSC1

PS4

DM2

DM1

DM0

PS3

PS1

PS2

DSC2

DSC4

DSC3

COUNTER

PMT1

PMT2

PMT3

PMT4

LabWindowsCVI/Excel

NIM-TTL

COINCIDENCE

Detectors in Lab & Deployed

1. D0 with 5mm aluminum electron-shield.2. DM0 on detector mounting fixture.3. DM1 on extended mounting fixture.4. (2x2)+(3x3) coincidence testing.5. Fully configured telescope deployed on Tate roof.

21

3 4

5

Technical Issues• Temperature Stability

– PMT Efficiency.

– Power Supply & PC overheating.

• Precipitation– HV Cable & PMT protection.

• Calibration– PMT Efficiency “Plateau” 2kV Power Supplies in Cooling Tent

L2R: DISC, COINC, NIM-TTL, 2xCounter

Detector/PMT Response Curve (PESTILENCE), [Source = Cobalt-60]

10.000

100.000

1000.000

10000.000

100000.000

1200 1300 1400 1500 1600 1700 1800

-VDC(PMT)

coun

ts/s

ec

Experimental Data I

• Random Coincidence Calculation– dt = 10-8sec T = 8.64104sec

• NRandom(max) = 8.6110-5

Events/Bin (theta=75.1deg)

0

5

10

15

20

25

30

35

40

45

50

55

60

65

70

75

0 50 100 150 200 250 300 350 400 450 500 550 600 650 700 750 800 850 900

bin(t=100sec)

even

ts

events(0)

events(75.1deg)

dtT

NN

NN

dtT

NNN

TotalRandom

TotalRandom

2

21

21

Events/Bin (theta=44.6deg)

0

5

10

15

20

25

30

35

40

45

50

55

60

65

70

75

0 50 100 150 200 250 300 350 400 450 500 550 600 650 700 750 800 850 900

bin(t=100sec)

even

ts

events(0)

events(44.6deg)

Events/Bin (theta=15.1deg)

0

5

10

15

20

25

30

35

40

45

50

55

60

65

70

75

0 50 100 150 200 250 300 350 400 450 500 550 600 650 700 750 800 850 900

bin(t=100sec)

even

ts

events(0)

events(15.1deg)

Raw Counts for: (WEST) = (15º, 45º, 75º)

Experimental Data IIPlots of F()/F(0) vs & cos2(): 24 Hours

Muon Flux Ratio F()/F(0) [24Hours]

0.0666

0.2477

0.5065

0.7470

0.9320

1.0000

0.9320

0.7470

0.5065

0.2477

0.06660.083

0.179

0.425

0.705

0.905

1.000

0.829

0.667

0.417

0.198

0.087

0.000

0.100

0.200

0.300

0.400

0.500

0.600

0.700

0.800

0.900

1.000

1.100

-90.0 -75.0 -60.0 -45.0 -30.0 -15.0 0.0 15.0 30.0 45.0 60.0 75.0 90.0

theta(deg)

F(th

eta)

/F(0

)

cos 2(theta)

F(theta)/F(0)

Poly. (cos 2(theta))

Muon Flux Ratio F(theta)/F(0), [DAY]

0.0666

0.2477

0.5065

0.7470

0.9320

1.0000

0.9320

0.7470

0.5065

0.2477

0.06660.087

0.185

0.443

0.724

0.9771.000

0.856

0.768

0.423

0.199

0.088

0.000

0.100

0.200

0.300

0.400

0.500

0.600

0.700

0.800

0.900

1.000

1.100

-90.0 -75.0 -60.0 -45.0 -30.0 -15.0 0.0 15.0 30.0 45.0 60.0 75.0 90.0

theta(deg)

F(th

eta)

/F(0

)

cos 2(theta)F(theta)/F(0)Poly. (cos 2(theta))

Plots of F()/F(0) vs & cos2(): DAY

Experimental Data III

Muon Flux Ratio F(theta)/F(0), [NIGHT]

0.0666

0.2477

0.5065

0.7470

0.9320

1.0000

0.9320

0.7470

0.5065

0.2477

0.06660.080

0.173

0.407

0.642

0.857

1.000

0.814

0.635

0.408

0.196

0.086

0.000

0.100

0.200

0.300

0.400

0.500

0.600

0.700

0.800

0.900

1.000

1.100

-90.0 -75.0 -60.0 -45.0 -30.0 -15.0 0.0 15.0 30.0 45.0 60.0 75.0 90.0

theta(deg)

F(th

eta)

/F(0

)

cos 2(theta)F(theta)/F(0)Poly. (cos 2(theta))

Experimental Data IVPlots of F()/F(0) vs & cos2(): NIGHT

Acknowledgements & ReferencesDr. Jeremiah Mans, Dr. Michael DuVernois, Kurt Wick, Paul Hinrichs, Dave Lee

References• Cosmic Rays, T.K.Gaisser, T.Stanev, (Bartol Research Inst, Univ. of Delaware), 2002, Rev. P.V.

Sokolsky (Univ. of Utah), R.E.Streitmatter, 2005.

• Anisotropy of Primary Cosmic Ray Flux in Super-Kamiokande, Y.Oyama (KEK), 2006, IPNS Seminar (KEK).

• Background Cosmic Ray Flux Measured by Balloon Flight Engineering Model, T.Kamae, GLAST-LAT Collaboration Meeting at NASA-Goddard, 2002.

• Terrestrial Cosmic Ray Intensities, J.F.Ziegler, IBM Journal of Research and Development, Vol. 42, #1, 1998.

• Measuring the Lateral Width of Cosmic Ray Particle Showers, G.Beebe, R.Peters, Department of Physics and Astrophysics, University of Minnesota, May 2006.

• High Energy Astrophysics, Volume #1: Particles, Photons and their Detection, M.Longair, Cambridge University Press, New York, 1981, 1992.

• Introduction to Elementary Particles, D.J.Griffiths, John Wiley & Sons Inc., 1987.

• Quantum Physics of Atoms, Molecules, Solids, Nuclei and Particles, 2nd Ed., R.Eisberg, R.Resnick, John Wiley & Sons, Inc., New York, 1974, 1985.

• Review of Particle Physics: Particle Physics Booklet, Physical Review D-66, K.Hagiwara et al, 2002.

• S.J.Sciutto, AIRES Project, Department of Physics, Universidad Nacional de La Plata, Argentina.