Physics


Research in Physics – Early Writings

Timo McIntosh, B.S. Physics., MFA Photography

Getting a degree in physics is an intense boot camp of calculations and mathematical technique. Presenting concepts that are developed with equations and numbers is a challenge and skill that takes practice and precision. These articles represent the first baby steps in the acquisition of that skill.

Timo got off to an early start in his training by participating in an undergraduate research program which let him pair up with a professor that was conducting current and publishable research.The idea was to provide young students with guidance and training in their budding science careers through mentorship. As a requirement of the program, each student is responsible for writing a paperunder the supervision of their mentor. The papers were about their ongoing research. Timo’s superconductor work was presented in 3 Undergraduate Research Conferences at his University,and at one poster conference held in Washington D.C. by the SACNAS organization. Timo’s astronomy research didn’t result in an presentations but was just as important in developing his science skills.

The final article on quantum computing was a term paper for Timo’s atomic physics class his senior year. It was meant to be an introduction to technical writing for Timo and his fellow students,but by the time he wrote it, he had already been working hard at developing his article writing skills.

These articles are on obscure topics in physics and don’t represent anything ground breaking, but they are a small window onto the world of science. They are not technically rigorous, but hopefully theyshow enough detail to demonstrate the challenges scientists face when trying to interpret their work for the rest of the world to view.

Theoretical Superconductors
Simulated Vortex Lines (Image from Mathematica animation)
THE PEAK EFFECT IN TYPE II SUPERCONDUCTORS 

Timothy K. McIntosh. Dept. of Physics.,University of California, Davis, Davis, CA 

Onnes’ discovery of low temperature superconductors ( less than 25 K ) in 1911 did not immediately produce practical applications like the development of high temperature superconductors ( 135 K ) did in 1986. In “type II” high temperature superconductors, a magnetic field penetrates the sample, leading to several magnetic flux phases, similar to the phases of matter. The phases of the magnetic field change through temperature and field variations. Using molecular dynamics, theoretical models, and computers with the FORTRAN programming language, we can develop programs which simulate these flux states and vortex phase changes. It was found experimentally that during the transition from superconductor to normal metal, there is a peak in the maximum current the superconductor can carry. The peak in some cases can increase the critical current up to 10 fold. Theoretical models based on computer simulations are revealing the conditions involved in these peak effects. We are examining the mechanism of the peak effect and generating evidence to support current theories. Understanding the peak effect will lead to the utilization of this effect in the production of superconductors.

Abstract from the Sacnas National Conference, Oct. 8-11, 1998. Overview paper from 1997.

Astrophysics and Astronomy
VLA RADIO OBSERVATIONS OF GALAXY NGC4911 IN THE COMA CLUSTER

Timothy K. McIntosh. IGPP, Lawrence Livermore National Laboratories, Livermore, CA

    Galaxy NGC4911 is a large Sbc spiral galaxy  in the Coma cluster, with ~ 10^9 Solar masses ( Giovenelli & Haynes 1985 ). The Coma cluster is dominated by two giant spiral galaxies that lie in the cluster core, who are surrounded by an x-ray IGM field. NGC4911 is .25 degrees from the cluster center and has a recession velocity of ~8000 m/s. NGC4911 lies within a small out-crop of the x-ray IGM, and it is believed that this medium is exciting the leading arm of the galaxy, spurring star formation. Optical images show that the arm of the galaxy facing the cluster core and the direction of the galaxy’s travel, is more luminous than the trailing arms. A Digital Sky Survey ( DSS ) image  shows the increased luminosity of the leading edges. This IGM is also thought to be blowing on the hydrogen gas within the galaxy itself, which would be revealed in neutral hydrogen ( HI ) studies as a concentration of HI in the trailing arm with little or none in the leading arm.

From a paper written at IGPP, as presented to MURPPS and Michael Gregg Ph.D. Aug. 16 1998.

Quantum Computing
Authors Notes:
Ever wonder about those hokie technologies that seem like science fiction, but you think might be under development at some secret lab? Quantum computing? I put this review together for my atomic physics class, based on the latest published work. Coming from a background in science, I hope that presenting this type of work will dispell your urges to believe in techno-gossip. The truth is speculation isn’t science, and true experiments and development take years of work and have to be based in the rigors of theory. I tried to find the real science behind all the rumors.
THE USE OF NMR AS A QUANTUM COMPUTER

Timothy K. McIntosh. University of California, Davis, Davis California Physics 121

In 1982, Feinman suggested that quantum computing would be exceptionally better at simulating quantum particles than classical computers. This speculation was developed into a full set of theories by the start of the 1990’s, and Computational algorithms were developed that would utilize the unique processing power of a quantum computers. Chasing an exponential speed up of classical computers, scientists began developing methods for carrying out he quantum algorithms.

From a paper written for an atomic physics class, presented March 17, 2000.

Leave a Reply