|What is Aurora?
Aurora means Roman Goddess of Dawn. Aurora displays are related to solar activity. When the Sunspot activity is maximum, then this solar wind can turn into a solar storm. It takes 2 days for the solar wind to reach the Earth. Solar winds particles follow the magnetic field lines. They are trapped in the ionosphere of the earth. They excite the gaseous molecules and the molecules while returning to the ground state emit light at a particular frequency. This is commonly know as Aurora Borealis in the northern hemisphere of Earth and Aurora Australis in the southern hemisphere of Earth. ("Aurora Borealis," the Latin name of the aurora of the northern hemisphere, means "northern dawn").
Our Project Work
Purpose of the Project: We are not fortunate enough to observe aurora from our location. So it was a humble effort made by us to produce an aurora display device which can simulate aurora.
Apparatus: Vacuum Pump, induction coil, ring magnet, to electrodes, Bell Jar, etc.
We have arranged two electrodes (cathode made up of copper and anode make up of aluminum) in vacuum jar as shown in photograph. In case of natural aurora voltage between the magnetic tail and the poles, like the voltage between the two terminals of a battery, can reach about 10,000 volts. In case of natural aurora the solar wind is the main cause. But in our case we have to supply sufficient voltage to obtain the discharge. In our case also the voltage applied between the electrodes is up to 10, 000 V. This voltage is applied using an induction coil. The distance between the two electrodes is variable (approximately from 5 to 10 cm). The pressure in the bell jar is 23 mm of Hg. A vacuum pump that is used in this experiment, is a Rotary Pump. Magnetic field of Earth is simulated by a permanent ring magnet having capacity 1.2 KG.
The discharge obtained in the bell jar is pinkish blue in color. The color is so because of nitrogen gas molecules present in the bell jar. The discharge moves along magnetic force lines. The discharge can be seen until there is supply of voltage. Vacuum Pump can be switched off when sufficient vacuum is obtained.
We are now trying to obtain different colors of aurora using the same device and but using different gases. We are also trying to simulate auroral ovals and conjugate auroras.
1. Joseph W Chamberlain: Physics of the aurora and Airglow (1961). Academic Press, London.
Name: Miss Ekata Hemant Ghate (M.Sc.Physics)
E-mail Address: firstname.lastname@example.org
Working place: Sir Parashurambhau College, Physics Department, India
Designation: Lecturer in Physics
Students who work under my guidance in this project (Both these students are in second year of graduation)
1. Miss Tejaswini Dalvi
Email Address: Tejdalvi@yahoo.com
2. Miss Ruta Prakash Patil
Email Address: Ruta15@yahoo.com