Physics Commons^™

Construction And Optimization Of A Tapered Amplifier System For Applications In Ultra-Cold Plasma Research, Ryan Cole

Honors Theses

The number density of cold atoms confined in a magneto-optical trap (MOT) is critically dependent on the intensity of the lasers used to cool the sample. To generate large optical powers while retaining the practicality of homemade external cavity diode lasers (ECDLs), a tapered amplifier (TA) system was designed and constructed to amplify the output of an existing 780 nm, continuous-wave ECDL. The amplifier’s performance is discussed in terms of its gain and power output. Under standard operating conditions, optical amplification of 12 dB is achieved, with a maximum power output of 0.75 W. The completed amplifier is installed into …

Electronic Detection Of Ultra Cold Neutral Plasma, Nirakar Poudel

Honors Theses

The project was started with an objective to investigate the effect of radio fre- quency absorption in Ultra Cold Neutral Plasmas (UNPs). The plasma oscillation is density dependent and can be excited by using external radio frequency field. A homodyne circuit is used to detect direct absorption of the radio frequency waves. The radio frequency waves are applied to conducting meshes which lie on either side of the plasma. The meshes are effectively a capacitor, which together with inherent circuit resistance constitute a high pass filter. A small part of the gain and phase shift of the filter depend on …

Diagnostics For Ultracold Plasma Experiments, Lauren Rand

Honors Theses

The goal of this experiment was to observe the effects of variations of experimental conditions on the ultracold plasma that formed as a result. The wavelength and power of the ionizing laser were varied to change the electron temperature and plasma density. The delay between the ionizing laser and the field ionization pulse was changed as well. In each case, plasma evolution and the resulting distribution of Rydberg states were observed. It was found that both electron temperature and plasma density directly affected the plasma lifetimes. However, neither electron temperature nor plasma density nor delay length had an effect on …

Interactions Of Electrons And Rydberg Atoms In Ultra-Cold Plasmas, Cristian Vesa

Honors Theses

This thesis discusses an experimental technique for investigating electron temperature control by Rydberg atoms in ultra-cold plasmas. The objective we set ourselves was twofold. Firstly, we sought to gain an insight into the processes whereby the creation of Rydberg atoms within the plasma lengthens the lifetime of the plasma. To this end, we created the plasma using a Littman dye laser and subsequently, at a variable time delay, we excited neutral atoms in the plasma to specific Rydberg states using a narrow bandwidth pulsed dye laser. Secondly, we employed radio-frequency (rf) electric fields to excite electron oscillations within the plasma …

Dynamic Phase Steepening In Alfven Waves, Stephen R. Granade

Honors Theses

Our solar system contains more activity and complexity than can be seen through a telescope. One such "invisible" phenomenon is the solar wind, created by a steady stream of particles blasted away from the sun in all directions. The sun's donut-shaped magnetic field lines channel this stream. Particles moving along the field lines perform an intricate helical dance, with ions winding one way and electrons the other.

The solar wind shapes and is shaped by the magnetic fields of the planets and the sun. If left undisturbed by outside influences, the earth's magnetic field, like the sun's, would resemble a …