Solar Interiors and Neutrons in Space Travel | ESS 102, Study notes of Environmental Science

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Notes

• Test Material:

Up to and including Solar Neutrinos

No Helioseismology

• Office Hrs Today 2-4 pm JHN 243

• Recommended Reading in Lang

Chpt. 2: Solar Interiors

Chpt. 3: Solar Neutrinos

Chpt. 4: Helioseismology (today and Mon)

Chpt. 5: Magnetic Sun (next week)

Chpt. 6: Solar Atmospheres (next week)

Where we are headed in the next 3-4 lectures

Light

Layers of the Sun

Solar Magnetic

Field and

Atmosphere

Sun’s energy production and transport

Solar Neutrinos

Helioseismology

What was the basis for Pauli’s hypothesis for the existence of the neutrino?

1. To explain why

protons repel each other

2. To conserve energy

and momentum in the neutron decay reaction

3. To explain charge

conservation in the P-P Chain

To explain why proto..To conserve energy ...To explain charge co...

11%

42%

48%

Solar Neutrinos:

/ Neutrinos were ‘invoked’ to solve a problem with energy (E) and momentum (!) conservation.

Decay: N " P + e -^ + (missing E &! )

/ Aolfgang Pauli suggested that a new particle, the neutrino (little neutral one, named by Italian Enrico Fermi) carried this energy and momentum away.

The Solar Neutrino Spectrum:

P + P " D+ e +^ + #$

[ 3 He + 4 He "^7 Be]

7 Be + e- " 7 Li + #$

[ 7 Be + P "^8 B]

8 B " 7 Be + e+ + #$

Neutrino Reactions in the Sun:

8 B

7 Be 7 Be

(1FeV H 1.6 x 10 -1M^ J)

The contributions of the different neutrino types depend on conditions in the Solar Core.

First Detection Solar Neutrinos

HomestaQe Fine Experiment led by Ray Davis in South DaQota 1.S Qm underground 1T6S-1TU7:

/M7U,000 liters of cleaning fluid (chlorine).

/Ahen neutrino interacts argon is produced.

37 Cl + #$$" 37 Ar + e -

[E # = 0.8 MeV]

/Feasures W one neutrino every 2 days.

(17p+20n) (18p+19n)

The Solar Neutrino Problem

/ Standard Fodel of the Sun says that

HomestaQe should detect W1.S Y

neutrinos per day, but it only detects 0.S

per day. Factor of M-[ difference.

/ Either we don’t understand the sun liQe

we thought we did, or something else is

going on.

The Solar Neutrino Problem:

/ Adding up all the neutrinos does not get the amount predicted in the Standard Model of the Sun , regardless of the method used^^^

Possible Solution to Solar Neutrino

Problem: Neutrino Oscillations

/ Neutrinos are oscillating between

different types (or flavors) as they travel

from the sun to earth.

/ Three flavors: electron neutrino !e, muon

neutrino !_ and tau neutrino! ".

/! e produced in the solar core are

oscillating or changing into !_ or! T before

they reach earth.

/ `uantum mechanics says that if

neutrinos oscillate, they must have non-

zero mass. Changes standard model of

particle physics.

How do we Qnow if neutrinos oscillateb

csing very large omni-directional sensors of water and

heavy water. Feasure a lacQ of !e and overabundance of

other flavors

Aater dased: SupereamioQande in Japan, S0,000 tons of water

/Able to detect! (^) e above 7.S FeV

/! (^) e scatter with e-^ in water, producing e-^ that travel faster than c in water which produces radiation detected by thousands of photomultiplier tubes

/Feasured lacQ of! (^) e (liQe HomestaQe)

Great Days in Science (to miss worQg):

The Seh detector was built with 11,200 Hamamatsu

photomultiplier tubes looQing at a [0m deep pool of

S0,000 tons of water.

/ hn November 12, 2001, the Seh was being refilled with water after servicing.

/ Just as they were completing the fill, a single tube at the bottom imploded from the pressure.

/ The shocQ wave from the implosion destroyed 10,000 more tubes in a chain reaction.

The Solar Neutrino hbservatories:

Neutrino observatories are defined mainly by the energy range they can sample.

Neutrinos are hard to measure, so the detectors are large

and omni-directional.

Heavy Aater: Sudbury hbservatory (SNh) in Canada 1000 tons of D (cA Physics main cS participator):

/Can detect all flavors of neutrinos (! (^) e ,! (^) _ ,and !" ) above WS FeV

/Feasured lacQ of! (^) e and abundance of! (^) _ and/or! (^) "

/dest evidence for neutrino oscillations and thus massive neutrinos

Neutrino jProblem’b

/ kn June of 2001, the SNh team reports that the neutrino deficit is solved ^^^^

/ The Standard Fodel of the Sun is right and Neutrinos should have mass^

/ The newest Neutrino detector will be in Antarctica.

/ “AMANDA” will be the largest and most sensitive detector ever. kt will find the direction of neutrinos^

The Future of Neutrino Astronomy:

END OF MATERIAL FOR

TEST 1

Helioseismology to Probe the Solar knterior

The long and Ainding Road:

/ The importance of solar neutrinos is that they tell us the solar furnace is alive and well.

/ The solar neutrino problem also shows us something about ourselves and the scientific method.

/ Solar Fusion was discovered because of a question about geology ^

/ The mass properties of neutrinos were discovered because of a question about energy production in the Sung.

/ Plus, we have only discovered the mass properties of neutrinos in the past S years^

Foving hng.

/ Solar Neutrinos tell us the fusion reactor in the Sun is worQing

/ Neutrinos offer little information about the layers of material between the core and our detectors.

/ For that we will need another tricQ.

Ringing the dell

/ Another means of probing the solar interior comes from a technique well Qnown on the earth, the study of wave propagation across the interior.

/ kf we looQ at the Sun we are able to sun a complex pattern of rising and falling material across the photosphere.

/ knitially one might conclude that there is no pattern to these observations.

Ringing the dell

/ Another means of probing the solar interior comes from a technique well Qnown on the earth, the study of wave propagation across the interior.

/ kf we looQ at the Sun we are able to see a complex pattern of rising and falling material across the photosphere.

/ knitially one might conclude that there is no pattern to these observations.

That instinct is wrongg

Dopplergrams:

/ The Doppler effect describes the effect of motion toward or away from an observer by a source of light or sound.

/Something moving toward you will have the frequency of light/sound increase (blue shifting). /Something moving away will have the frequency (Red shifting)

/ dy picQing a single emission line (liQe Sodium) to study, it is possible to use the Doppler effect to identify upwelling and down- welling regions.

/ A Dopplergram is a way of looQing at rising and falling regions in the photosphere.

Doppler Effect

Sound Waves

Red shifting of

emission lines

Light Waves

Random Noise or hrderb

/ A single Dopplergram looQs fairly random with small cells about 10 M^ -10 [^ Qm across.

/ Stringing them together doesn’t bring any patterns out

Sorting the Notes:

/ A common problem in physics is the separation of multiple component signals from apparent noise. (liQe picQing a single note from a symphony.)

/ nou encounter this in everyday life^ Ahat do you have without a tuner on your TVb Noise^

nour TV tuner turns this.

Sorting the Notes:

/ A common problem in physics is the separation of multiple component signals from apparent noise. (liQe picQing a single note from a symphony.)

/ nou encounter this in everyday life^ Ahat do you have without a tuner on your TVb Noise^

nour TV tuner turns this. knto all of this ^^