Cyclotron Resonant Heating and Acceleration of protons, O VI & Mg X ions in the North Polar Coronal Hole

E. Rennan PEKÜNLÜ; Kadri YAKUT; Hicran ŞART

Makale detayları

Cyclotron Resonant Heating and Acceleration of protons, O VI & Mg X ions in the North Polar Coronal Hole

Yazarlar:

E. Rennan PEKÜNLÜ | Kadri YAKUT | Hicran ŞART

Yayıncı:

TUBITAK

Dergi:

Turkish Journal of Physics 2004 Vol.28 Issue 6, pp.407-418

Belge Tipi:

Makale

Yayın Tarihi:

5/2004

Belge Dili:

Türkçe

Document ID (Org No.):

2000761649

Sıklık:

İki Aylık

eISSN:

1303-6122

pISSN:

1300-0101

Anahtar kelimeler:

Özet:

 

Ultraviolet Coronograph Spectrometer aboard Solar and  Heliospheric Observatory (SOHO) has revealed the existence of  temperature anisotropy of many minor ion species that populate the  north solar polar coronal hole.  In this study, we examined the  propagation characteristics of ion-cyclotron waves which resonate with  protons, O VI and Mg X ions.  In our empirical model, radial variation  of the magnetic field, electron and ion number densities,  perpendicular and parallel temperature of protons, O VI and Mg X ions  are adopted from the measurements of various instruments aboard SOHO.  Since most of the measurements of SOHO instruments begin at 1.5 R  (=r/R\odot) where the collisionless plasma properties dominate  towards the outer regions, we assumed bi--Maxwellian velocity  distribution functions for protons, O VI and Mg X ions.  Dispersion  relation for the left circularly polarized ion cyclotron waves which  are assumed to be generated at the bottom of the coronal hole is  deduced.  We do not consider the in situ generation of these waves.   We found that ion cyclotron waves with frequency band 2.5 kHz - 10 kHz  come into resonance with O VI ions between 1.5 R - 3.0 R .  We also  solved the dispersion relations for protons and Mg X ions in the same  distance range and have shown that the waves of 2.5 kHz - 10 kHz  frequency band preferentially heat the O VI ions.  O VI ions come into  resonance with ion cyclotron waves of certain frequency long before  the protons and the Mg X ions.  We do not know the evolution of the  power spectrum of these waves.  Therefore it is hard to tell if, after  having been depleted partly (if not, totally) by O VI ions, any power  is left over from ion cyclotron waves for either protons or Mg X ions.   But if cyclotron resonance process is to be favored for the  perpendicular heating, then we may hypothesize that ion cyclotron  waves, after having heated the O VI ions first, have enough power left  to heat protons and Mg X ions in the same distance range.

 

Ultraviolet Coronograph Spectrometer aboard Solar and  Heliospheric Observatory (SOHO) has revealed the existence of  temperature anisotropy of many minor ion species that populate the  north solar polar coronal hole.  In this study, we examined the  propagation characteristics of ion-cyclotron waves which resonate with  protons, O VI and Mg X ions.  In our empirical model, radial variation  of the magnetic field, electron and ion number densities,  perpendicular and parallel temperature of protons, O VI and Mg X ions  are adopted from the measurements of various instruments aboard SOHO.  Since most of the measurements of SOHO instruments begin at 1.5 R  (=r/R\odot) where the collisionless plasma properties dominate  towards the outer regions, we assumed bi--Maxwellian velocity  distribution functions for protons, O VI and Mg X ions.  Dispersion  relation for the left circularly polarized ion cyclotron waves which  are assumed to be generated at the bottom of the coronal hole is  deduced.  We do not consider the in situ generation of these waves.   We found that ion cyclotron waves with frequency band 2.5 kHz - 10 kHz  come into resonance with O VI ions between 1.5 R - 3.0 R .  We also  solved the dispersion relations for protons and Mg X ions in the same  distance range and have shown that the waves of 2.5 kHz - 10 kHz  frequency band preferentially heat the O VI ions.  O VI ions come into  resonance with ion cyclotron waves of certain frequency long before  the protons and the Mg X ions.  We do not know the evolution of the  power spectrum of these waves.  Therefore it is hard to tell if, after  having been depleted partly (if not, totally) by O VI ions, any power  is left over from ion cyclotron waves for either protons or Mg X ions.   But if cyclotron resonance process is to be favored for the  perpendicular heating, then we may hypothesize that ion cyclotron  waves, after having heated the O VI ions first, have enough power left  to heat protons and Mg X ions in the same distance range.

Makale detayları

Cyclotron Resonant Heating and Acceleration of protons, O VI & Mg X ions in the North Polar Coronal Hole

Yazarlar:

E. Rennan PEKÜNLÜ | Kadri YAKUT | Hicran ŞART

Yayıncı:

TUBITAK

Dergi:

Turkish Journal of Physics 2004 Vol.28 Issue 6, pp.407-418

Belge Tipi:

Makale

Yayın Tarihi:

5/2004

Belge Dili:

Türkçe

Document ID (Org No.):

2000761649

Sıklık:

İki Aylık

eISSN:

1303-6122

pISSN:

1300-0101

Sun: solar corona: ion--cyclotron waves

heating.

Sayı

Makale detayları

Cyclotron Resonant Heating and Acceleration of protons, O VI & Mg X ions in the North Polar Coronal Hole

Yazarlar: E. Rennan PEKÜNLÜ | Kadri YAKUT | Hicran ŞART

Yayıncı: TUBITAK

Dergi: Turkish Journal of Physics 2004 Vol.28 Issue 6, pp.407-418

Belge Tipi: Makale

Yayın Tarihi: 5/2004

Belge Dili: Türkçe

Document ID (Org No.): 2000761649

Sıklık: İki Aylık

eISSN: 1303-6122

pISSN: 1300-0101

Sun: solar corona: ion--cyclotron waves

heating.

Sayı

Yazarlar:

E. Rennan PEKÜNLÜ | Kadri YAKUT | Hicran ŞART

Yayıncı:

TUBITAK

Dergi:

Turkish Journal of Physics 2004 Vol.28 Issue 6, pp.407-418

Belge Tipi:

Makale

Yayın Tarihi:

5/2004

Belge Dili:

Türkçe

Document ID (Org No.):

2000761649

Sıklık:

İki Aylık

eISSN:

1303-6122

pISSN:

1300-0101