Department of Physics

Facilities

Atomic Lab.
In our atomic and molecular physics lab, a high resolution imaging technique for electron-atomic and electron-molecular collisions has been built and operated. This technique is known as COLTRIMS which stands for COLd Target Recoil Ion Momentum Spectroscopy. We used our COLTRIMS imaging technique to measure the complete fragmentation of a few body system. All charged fragments resulted from an atomic or molecular collision are projected by a combination of electric and magnetic fields onto large area position sensitive detectors. From the measured times-of-flight of the particles and their positions of impact on the detectors, the three dimensional momentum vectors of the particles are obtained. Cooling of the the target atoms before the fragmentation by supersonic expansion allows a momentum resolution for the ion momenta of 0.05 a.u. (atomic units). Multi hit capable position channel plate detectors with delayline readout are used for detection of several electrons or ions per detector.


Impedance Spectroscopy Laboratory
AC-voltage impedance spectroscopy analyzer is applied on solid materials and liquid samples using a in the frequency range of 1 MHz down to 10-3 Hz to determine the dielectric properties of the material by measuring the resulting electrical current. A holder connection unit allows the 4-point-probe of dielectric sample characterization. A high temperature sample holder in combination with furnace offers the possibility of temperature depending measurements from 20 °C to 500 °C.

Application
Investigating the dielectric properties of solids and liquids in a wide range of frequencies. The measured physical quantities are ionic conductivities, activation energies and diffusion coefficients for polymers, crystalline and non-crystalline materials. Also, some electric properties of biological materials are measured in this laboratory. These experiments are performed in a close collaboration with the Chemistry Department/Hashemite University.

The Quantum Design Physical Property Measurement System (PPMS)  EverCool-II is a cryogen-free which enables the cool-down procedure with only a standard helium gas cylinder. the PPMS is designed to run 24 hours a day, 7 days a week. Many physical properties may be measured by easily changing the options such as heat capacity, Raman & Luminescence Spectroscopy System, DC resistivity and magnetometry.

The running option in our lab so far is the Vibrating sample magnetometer (VSM) which operates on Faraday's Law of Induction, which tells that changing the magnetic flux will induce a voltage (emf) in a pickup coil. The measurement is performed by oscillating the sample near a detection  coil while detecting the voltage induced. The precise position and amplitude of oscillation is controlled from the VSM motor module using an optical linear encoder signal readback from the VSM linear motor transport. By performing relatively large oscillation amplitude (1-3 mm peak) and a frequency of 40 Hz, the system may resolve magnetization of less than 10-6 emu. The measurements may be performed under a very low temperatures of around 4 K and high magnetic fields up to nine Tesla. Magnetization changes with Magnetic field, temperature and time may performed.