PAKISTAN - QAU

PLASMA PHYSICS RESEARCH AT THE
DEPARTMENT OF PHYSICS
QUAID-I-AZAM UNIVERSITY, ISLAMABAD 45320

Islamabad 45320

Theoretical Group

Telephone: +92 51 2829472
Telefax: +92 51 9210256
E-mail: amirza@qau.edu.pk
            a_m_mirza@yahoo.com

Mirza, Arshad M. (Head)
Adnan Sarwar, M.
Ahmad, Zahoor
Ajmal Khan, M.
Ansar Mahmood, M.

Azeem, Irfan
Azeem, M.
Iqbal, M.
Javaid Iqbal, M.
Ilyas, Muhammad

Nawaz, Hassan
Qamar, Anisa
Yaqoob, Faisal

Research activites:

1. The implosion dynamics and thermonuclear fusion parameters of a spinning gas-puff staged pinch has been investigated for a DT-fibre plasma seeded with Kr-impurity. The effects of anomalous heating, line radiations from Kr, alpha particle heating and radiative collapse are studied for different spin velocities, keeping the spin coupling parameter f_o (=0.1) fixed. Our numerical analysis suggests that a judicious choice of spin velocity can provide the desired temperature and density when a DT-fibre plasma is seeded with a small fraction of Kr-impurity to initiate radiative collapse.
2. A nonuniform partially ionized magnetoplasma is known to be unstable against electromagnetic perturbations. The source of free energy for the instability is sheared magnetic-field-aligned ion flow, which is coupled to the electromagnetic waves via charge particle-neutral collisions. Our analytical as well as numerical studies for the ionospheric parameters suggest that electromagnetic waves grow faster than their electrostatic counterparts. Furthermore, linearly excited electromagnetic waves in partially ionized collisional plasmas are shown to cause nonthermal cross-field transport of plasma particles, current filamentation and plasma diffusion in the ionosphere of the Earth.
3. We have estimated the energy loss of a test charged projectile in an unmagnetized dusty plasma for different dust parameters (such as dust charge state, dust number density, dust charge fluctuations and dust-neutral collison frequency) using Krook and BGK-type collisional models. We found that the higher the dust charge state the more pronounced is the wake field. The variation of the dust number density shows a similar behavior. For large dust-neutral collisions a weakly damped large amplitude wake-field has been observed which jumps ahead of the test charge position for large collision frequencies. The dust-neutral collisions are also found to enhance energy loss for test charge velocities greater than the dust acoustic speeds.
4. The wake-field excited by a test charge moving through a multicomponent dusty plasma has been calculated by using the fluid as well as the Vlasov-Poisson model. We found that the ion-wake field may be oscillatory, constant or exponentially decreasing, depending upon the test charge velocity relative to the dust acoustic speed. Our numerical results demonstrate the possibility of wake-field excitation for various test charge velocities.
5. The linear and nonlinear properties of electrostatic and electromagnetic waves in the presence of ion-temperature-gradient, magnetic field gradient, density gradient, and velocity gradients are examined. It is shown that parallel velocity shear couples the electrostatic and magnetostatic modes and can cause an instability. An estimate of the anomalous ion energy transport and particle flux on the basis of mixing length hypothesis is made and the results are discussed for some interesting limiting cases. Furthermore, it is shown that possible stationary solutions of the nonlinear equations without dissipation can be represented in the form of various types of vortices. On the other hand, the temporal behavior of the nonlinear mode coupling equations is found to be governed by the generalized Lorenz-Stenflo type equations, which admit chaotic trajectories.
   

Funding source(s); approximate funding level;	QAU-Research Fund
	ICAC-Research Fellowship
	Pakistan Science Foundation
	US $ 3500 per year (approx.)

Approximate staffing level; One Faculty Member and 12 Research Students.

Experimental Group

Telephone: +92 51 2273999
Telefax: +92 51 9210256
E-mail: mzakaullah@qau.edu.pk
            Zaka_qau_pk@yahoo.com

Zakaullah, Mohammad (Group Leader)
Abdul, Qayyum
Ahmad, Sarfraz
Hassan, Mohammad

Hussain, Safdar
Iqbal, Mohammad
Khalid, Alamgir
Murtaza, Ghulam

Sartaj
Shafique, Mohammad
Sharif, Mohammad

Research activites:
A 2.3 kJ plasma focus is in operation. The effects of different parameters like its anode length, material and shape, insulator sleeve length, material and contamination, parasitic inductance, gas pressure etc. on neutron and X-ray emission characteristics, electron and ion beam generation, have been studied. Correlation of different radiations (neutrons, X-ray, charged particles) is also investigated. With some modification in anode shape, the plasma focus is operated to enhance X-ray emission. With copper anode, 0.35% efficiency (with reference to energy stored in the capacitor bank) for Cu-K-α line, and 1.7% efficiency for over all X-ray generation is obtained. Experiments for Mo-K-α line and white X-rays of energy (15-20 keV) are in progress.

A small-scale cold plasma reactor is developed for plasma processing of materials, surface treatment to improve the surface quality, and thin film deposition/coating to give them desirable properties.

Funding source(s); approximate funding level;	Quaid-i-Azam University
	Pakistan Science Foundation
	US $ 5000 per year approximately.

Approximate staffing level; One faculty member, one technician, ten research students.