numerical studies of neutrino radiation in solar flares ryuji takeishi terasawa lab. m2 institute...
TRANSCRIPT
![Page 1: Numerical Studies of Neutrino Radiation in Solar Flares Ryuji Takeishi Terasawa lab. M2 Institute for Cosmic Ray Research The University of Tokyo 1](https://reader031.vdocuments.site/reader031/viewer/2022020417/56649cb15503460f9497635d/html5/thumbnails/1.jpg)
Numerical Studies of Neutrino Radiation
in Solar Flares
Ryuji Takeishi
Terasawa lab. M2
Institute for Cosmic Ray Research
The University of Tokyo
1
![Page 2: Numerical Studies of Neutrino Radiation in Solar Flares Ryuji Takeishi Terasawa lab. M2 Institute for Cosmic Ray Research The University of Tokyo 1](https://reader031.vdocuments.site/reader031/viewer/2022020417/56649cb15503460f9497635d/html5/thumbnails/2.jpg)
Overview
• Introduction
• Methods
• Results
• Discussion
• Conclusions
2
![Page 3: Numerical Studies of Neutrino Radiation in Solar Flares Ryuji Takeishi Terasawa lab. M2 Institute for Cosmic Ray Research The University of Tokyo 1](https://reader031.vdocuments.site/reader031/viewer/2022020417/56649cb15503460f9497635d/html5/thumbnails/3.jpg)
flare
An explosion on the solar surface
・ releases 1028~32erg in 101-3sec
・ accelerates particles
(proton: ~10GeV,electron: ~10MeV)
Solar Flare
3
pν ・ γ(line) ・n
eRadio ・X・ γObserving
secondary particlescan reveal flare acceleration mechanism
![Page 4: Numerical Studies of Neutrino Radiation in Solar Flares Ryuji Takeishi Terasawa lab. M2 Institute for Cosmic Ray Research The University of Tokyo 1](https://reader031.vdocuments.site/reader031/viewer/2022020417/56649cb15503460f9497635d/html5/thumbnails/4.jpg)
Solar Flare Region
~70 万 km~500km 2000km
Core
Radiativeenvelope
Convective envelope
Photosphere
Chromosphere
Corona
Magnetic reconnection→ Solar flare
νradiation
Protonreaction
4
![Page 5: Numerical Studies of Neutrino Radiation in Solar Flares Ryuji Takeishi Terasawa lab. M2 Institute for Cosmic Ray Research The University of Tokyo 1](https://reader031.vdocuments.site/reader031/viewer/2022020417/56649cb15503460f9497635d/html5/thumbnails/5.jpg)
Current detecter :No detection
Next detector :Calculation required
Solar Flare Neutrino Observation
5
Calculate neutrino event number in HKby simulating proton reaction in solar flare
Super-Kamiokande (SK)
Hyper-Kamiokande (HK)
![Page 6: Numerical Studies of Neutrino Radiation in Solar Flares Ryuji Takeishi Terasawa lab. M2 Institute for Cosmic Ray Research The University of Tokyo 1](https://reader031.vdocuments.site/reader031/viewer/2022020417/56649cb15503460f9497635d/html5/thumbnails/6.jpg)
Neutrino Generation Processes
6
• Proton acceleration ( up to ~10GeV )• Proton reaction in solar atmosphere
p + N → p + N´+ kπ+ + kπ - + rπ0
p + N → n + N´+ (k+1)π+ + kπ - + rπ0
• πdecay π± → μ± + νμ(νμ) , π0 → 2γ,
μ± → e± + νe (νe ) + νμ(νμ)
N: nuclei k , r : multiplicity H,He gas
p pπ
π
π+
νμ
μ+ e+
νe
νμ
![Page 7: Numerical Studies of Neutrino Radiation in Solar Flares Ryuji Takeishi Terasawa lab. M2 Institute for Cosmic Ray Research The University of Tokyo 1](https://reader031.vdocuments.site/reader031/viewer/2022020417/56649cb15503460f9497635d/html5/thumbnails/7.jpg)
Methods 1
7
• Use Geant4 toolkit• Set boxes stacked in the vertical direction as a modeled solar atmosphere
pp
Theoretical model( Gingerich et al. 1971 )Simulation model
![Page 8: Numerical Studies of Neutrino Radiation in Solar Flares Ryuji Takeishi Terasawa lab. M2 Institute for Cosmic Ray Research The University of Tokyo 1](https://reader031.vdocuments.site/reader031/viewer/2022020417/56649cb15503460f9497635d/html5/thumbnails/8.jpg)
Methods 2• 2 initial proton spectra
Model A Emax=10GeV
Np ∝ E-3
Np(>500MeV) = 1029
100GeV500MeV
∝ E-1
E
Np
10GeV500MeV
∝ E-3
E
Np
Powerd spectrum , Emin=500MeV , Ep = 1026erg
Model B Emax=100GeV
Np ∝ E-1
Np(>500MeV) = 5.1×1027
8
![Page 9: Numerical Studies of Neutrino Radiation in Solar Flares Ryuji Takeishi Terasawa lab. M2 Institute for Cosmic Ray Research The University of Tokyo 1](https://reader031.vdocuments.site/reader031/viewer/2022020417/56649cb15503460f9497635d/html5/thumbnails/9.jpg)
Methods 3
Magnetic mirror effect should
broaden proton pitch angle↓
proton injection angles distribute homogeneously over 2πSr
9
A:magnetic mirror ratio (A~10-2~-
1)
Np = 1029 → Np = 1029×A
p ν
![Page 10: Numerical Studies of Neutrino Radiation in Solar Flares Ryuji Takeishi Terasawa lab. M2 Institute for Cosmic Ray Research The University of Tokyo 1](https://reader031.vdocuments.site/reader031/viewer/2022020417/56649cb15503460f9497635d/html5/thumbnails/10.jpg)
Results 1• νfluence Φ on the Earth’s orbit from a solar flare behind the Sun
νe ,νμ
Φ= 19.7 / cm2
Energy fluence
= 2.1 GeV/cm2
<E> = 107MeV
νe ,νμ
Φ= 12.1 / cm2
Energy fluence
= 4.8 GeV/cm2
<E> = 400MeV
Model A Emax=10GeV, Np ∝ E-3 , Np=1029A
Model B Emax=100GeV , Np ∝ E-1 , Np= 5.1×1027A
νe , νμ
νe , νμ νe , νμ
νe , νμ
10
![Page 11: Numerical Studies of Neutrino Radiation in Solar Flares Ryuji Takeishi Terasawa lab. M2 Institute for Cosmic Ray Research The University of Tokyo 1](https://reader031.vdocuments.site/reader031/viewer/2022020417/56649cb15503460f9497635d/html5/thumbnails/11.jpg)
Event number in HK (Fargion et al. 2004)
Nev = Σ <Nν > σν (Eν ) NHK i = e , μi i i i
νfluencefrom simulationresults νcross section
Reaction particlenumber In HK
11
![Page 12: Numerical Studies of Neutrino Radiation in Solar Flares Ryuji Takeishi Terasawa lab. M2 Institute for Cosmic Ray Research The University of Tokyo 1](https://reader031.vdocuments.site/reader031/viewer/2022020417/56649cb15503460f9497635d/html5/thumbnails/12.jpg)
Results 2• Event number in HK from a solar flare behind the Sun
12
Model A Emax=10GeV, Np ∝ E-3 , Np=1029A
νe – p
νe – n
νe - e
νμ- eνμ- e
νμ– p
νμ– n
νe - e
total
νe – p (bound)νμ- p (bound)
νe – p
νe – n
νe - e
νμ- eνμ- e
νμ– p
νμ– n
νe - e
total
νe – p (bound)νμ- p (bound)
Model B Emax=100GeV , Np ∝ E-1 , Np= 5.1×1027A
Nev =9.9×10-4A
Nev =2.6×10-3A
![Page 13: Numerical Studies of Neutrino Radiation in Solar Flares Ryuji Takeishi Terasawa lab. M2 Institute for Cosmic Ray Research The University of Tokyo 1](https://reader031.vdocuments.site/reader031/viewer/2022020417/56649cb15503460f9497635d/html5/thumbnails/13.jpg)
Results 3• Event number in HK from different solar flare positions
13
ν
θ
Earth
Sun
behind the Sunin front ofthe Sun
Nev = 10-5A ~ 10-3A<< 1
preliminary
![Page 14: Numerical Studies of Neutrino Radiation in Solar Flares Ryuji Takeishi Terasawa lab. M2 Institute for Cosmic Ray Research The University of Tokyo 1](https://reader031.vdocuments.site/reader031/viewer/2022020417/56649cb15503460f9497635d/html5/thumbnails/14.jpg)
Discussion 1
• Neutrino event number from one solar flare is less than 10-5 ~ 10-3 , so detection in HK is difficult
• Solar flare neutrino detection requires ~103 times sensitivity , so it will not become noise of other signal
14
![Page 15: Numerical Studies of Neutrino Radiation in Solar Flares Ryuji Takeishi Terasawa lab. M2 Institute for Cosmic Ray Research The University of Tokyo 1](https://reader031.vdocuments.site/reader031/viewer/2022020417/56649cb15503460f9497635d/html5/thumbnails/15.jpg)
Crosby et al.(1992)Discussion 2
Estimate event frequency from solar flare frequency
• Model A (Emax=10GeV, Np ∝ E-3 , Np=1029A)
8.3A×10-3 / year → 120 / A year/1event
• Model B (Emax=100GeV, Np ∝ E-1, Np= 5.1×1027A) 1.9A×10-2 / year → 52 / A year/1event (Consider only solar cycle maximum and flare behind the Sun)
15
![Page 16: Numerical Studies of Neutrino Radiation in Solar Flares Ryuji Takeishi Terasawa lab. M2 Institute for Cosmic Ray Research The University of Tokyo 1](https://reader031.vdocuments.site/reader031/viewer/2022020417/56649cb15503460f9497635d/html5/thumbnails/16.jpg)
Conclusion
• Solar flareνevent number is < 10-3
• Detection in HK needs >100 year
• Solar flareνwill not become noises of otherνsignals
16