Propagation of cosmic rays through interplanetary medium

العناوين الأخرى

انتقال جسيمات الأشعة الكونية في الفضاء بين الكواكب

مقدم أطروحة جامعية

al-Samirrai, Umar Ahmad Abd al-Nabi

مشرف أطروحة جامعية

al-Birmani, Muhammad Jafar Fadil

الجامعة

جامعة بغداد

الكلية

كلية العلوم

القسم الأكاديمي

قسم الفلك و الفضاء

دولة الجامعة

العراق

الدرجة العلمية

ماجستير

تاريخ الدرجة العلمية

2005

الملخص الإنجليزي

The methods of propagation of cosmic rays in the solar system through the interplanetary magnetic field have been studied.

Convection diffusion and adiabatic deceleration.

The mechanism of modulation of galactic cosmic particles of very high energy > 30 GeV is investigated. The one dimensional transport equation had been solved numerically by the finite difference methods, by using the explicit and implicit methods. The time-dependent convection-diffusion equation solved by the FTCS method, i.e., the forward in time and centered in space.

This equation was solved under the assumption of constant diffusion coefficient and constant solar wind velocity and zero source term.

The results of this solution shows the behavior of the mean distribution function as a function of heliocentric radial distance. The one dimensional time-dependent transport equation (convection-diffusion and adiabatic-deceleration) and Compton-Getting factor was solved by the Implicit Crank-Nicolson method.

The distribution function obtained under the assumption of constant diffusion coefficient and constant solar wind velocity and zero source term, shows a Gaussian distribution in terms of heliocentric radial distance. Finally the Steady-State equation was solved by the Implicit Crank-Nicolson method.

The solution was performed under the following assumption: 1.

The radial component of the diffusion coefficient is of the form k = k ( p )rb o , where b >0 , b = 0 , and b >0 . 2.

The solar wind velocity is assumed exponential function of radial distance.

V =Vo éë1- exp(-13.862r )ùû 3.

Zero source term. The distribution function was obtained in terms of kinetic energy of cosmic particles.

The spectrum of cosmic particles in terms of kinetic energy was obtained from imperial formula.

The distribution function increases with the ratio A/Z (mass number to charge number of cosmic particles).

التخصصات الرئيسية

الفلك و علومه

عدد الصفحات

67

قائمة المحتويات

• APA
• MLA
• AMA

لغة النص

الإنجليزية

نوع البيانات

رسائل جامعية

رقم السجل

BIM-603346