Engineering Commons^™

Energetics And Kinetics Of Dislocation Initiation In The Stressed Volume At Small Scales, Tianlei Li

Doctoral Dissertations

Instrumented nanoindentation techniques have been widely used in characterizing mechanical behavior of materials in small length scales. For defect-free single crystals under nanoindentation, the onset of elastic-plastic transition is often shown by a sudden displacement burst in the measured load-displacement curve. It is believed to result from the homogeneous dislocation nucleation because the maximum shear stress at the pop-in load approaches the theoretical strength of the material and because statistical measurements agree with a thermally activated process of homogeneous dislocation nucleation. For single crystals with defects, the pop-in is believed to result from the sudden motion of pre-existing dislocations or …

Use Of A Press-Fit Grip Sleeve For Cable-In-Conduit Superconductor Integration: Effects Of Tensile And Fatigue Loading, Paul Michael Hayes

Masters Theses

Presently, one of the most promising sources for a future of abundant, low-emission, and efficient energy comes in the form of nuclear fusion. However, in order for it to become a reality, fusion technology must overcome the obstacle of plasma confinement. Utilizing the tokomak based design for magnetic plasma confinement; ITER is currently developing a fusion reactor to prove its commercial viability.

The purpose of this research was to determine the feasibility of pulling toroidal field cable with a press-fit grip sleeve that utilizes friction to generate a gripping force. Such a design is being considered by ITER to integrate …

Effect Of Moisture Absorption On The Sinter Quality Of Central Solenoid (Cs) Coil Pack, Zeshaan Sher Mohammed

Masters Theses

Fusion energy has been said to be the solution to all the world’s energy problems. The International Thermonuclear Experimental Reactor (ITER) is the flagship project to demonstrate the feasibility of fusion energy. The Central Solenoid (CS), an important component of the reactor, is needed to induce plasma current, initiate, ramp-up, ramp-down, and sustain plasma in a very controlled manner. In order to achieve this, the CS coil packs must be manufactured under controlled conditions. The CS conductor is an advanced cable-in-conduit Nb3Sn superconductor. The CS cable will be made in long continuous sections but with thousands of meter of cable …

Solid Target System For Use On An 11 Mev Cyclotron, Andrew Carl Williamson

Masters Theses

Molecular imaging is becoming an important contributor to the development of personalized medicine. Positron Emission Tomography (PET) is a technology that enables molecular imaging by allowing a physician to detect and map the location of various physiological processes. The purpose of this work is to design, fabricate and test a mechanism that would make the production of the PET isotope, copper-64 practical for both researchers and commercial suppliers. In order to have the maximum usefulness, the design needs to fit and operate within several constraints. A one dimensional thermal analysis indicated that operation of the system under existing cooling conditions …