Article Index


This page lists all of the abstracts for the Fall 2015 colloquium series. For dates and speakers, see Colloquium.

"Hunting and Discovering the Higgs Boson (“God” particle) at the LHC of CERN", Friday, September 4, 12:00pm, MH 606


Yongsheng Gao, California State University, Fresno

ABSTRACT: The Higgs boson (“God Particle”) was discovered in 2012 by the ATLAS and CMS experiments of the Large Hadron Collider (LHC) at the European Organization for Nuclear Research (CERN). This discovery was named by Science magazine as the 2012 “Breakthrough of the Year” and resulted in the award of the 2013 Nobel Physics Prize to the Higgs theory. Fresno State was the only CSU campus on ATLAS and involved in the Higgs discovery. I will talk about CERN, LHC, Higgs discovery, the Fresno State ATLAS program, the CSU Nuclear and Particle Physics Consortium (NUPAC), and opportunities for CSU students to work at CERN during summer on ATLAS research.

"Resonant Coherent Excitation of Highly-Charged Ions in Crystals", Friday, September 25, 12:00pm, MH 606


Alena Ananyeva, GSI Helmholtz Centre for Heavy Ion Research


ABSTRACT: The resonant coherent excitation of ions in the fast oscillating electrical field, with frequencies in the x-ray range, created by the periodic Coulomb potential of a crystal target is a phenomenon which holds a large potential for spectroscopic investigations in relativistic highly-charged ions. If the field frequency matches the energy difference between two electronic states, a resonant excitation of the ion became possible. The onset of the process can be steered by tuning the ion velocity by fix target orientation or the relative orientation of the incoming ion velocity and the crystallographic orientation. If the crystal orientation simultaneously permits frequencies for two different electronic transitions, a sequential resonant excitation to higher states becomes possible.

This contribution presents a series of experiments performed at GSI (Darmstadt, Germany) and HIMAC (Tokyo, Japan) facilities with relativistic beams of heavy ions and thin Silicon crystal-targets. The occurrence of the ions excitation was detected by measuring the charge-state distribution of the ions after the interaction with the crystal and the yield of the x-rays emitted during the decay of the excited states as a function of the relative orientation of the target to the beam direction.

The performed measurements clearly demonstrate that sequential 1s->2p->3s/3d electron transition in H-like Ar was experimentally observed together with the alignment of the magnetic substates of the ions by the polarised crystal field. Resonant coherent excitation was also successfully applied for a precision measurement of a 1s22s->1s22p3/2 electron transition in Li-like U.

"Flowers from other gardens", Friday, October 9, 12:00pm, MH 606


Jim Williams, University of Western Australia

ABSTRACT: From current research activity we have begun to observe and control the interplay between electron correlations, electron exchange, spin-orbit coupling, and field distortions within compound atomic structures. The studies of these physical interactions have accumulated from spin-polarized electron momentum probing exchange and spin-orbit coupling in free single atoms as well as spin polarized momentum dispersion in multilayered thin films and surfaces, elemental momentum density dispersion in doped perovskite oxides and in polymer blends such as polyvinyl and polyacetates using positronium coincidence doppler broadening for surface depth probing of elemental electron density dispersions. Our discussion will concern such concepts at an introductory level.

"Evolution of circumstellar disks and planet formation", Friday, October 16, 12:00pm, MH 606


Wladimir Lyra, California State University, Northridge

ABSTRACT: During the first million years of evolution, nascent planetary systems are embedded in dense disk-shaped clouds of gas. These circumstellar disks are home to a myriad of hydrodynamical processes, which bring about turbulence and the emergence of viscous¬-like behavior, enabling accretion of gas onto the protostar. Meanwhile, micron-sized dust grains embedded in the disk are growing through coagulation onto pebbles and rocks. Turbulence has a positive effect on these small solids, concentrating them into transient high pressure regions for long enough to achieve gravitational collapse into km-sized bodies, forming the first planetesimals. Giant storm systems in the disk, similar to Jupiter's Great Red Spot, may exist in quiescent zones of the disk. These are even more prone to collecting solid material, producing the first terrestrial planets and cores of giant planets. In this talk I will discuss the state of the art and recent advances in the field of planet formation, as well as pressing problems such as the structure observed in high-resolution sub-millimeter images of circumstellar disks, and how to interpret them.

"Compact Atomic Magnetometer for Magnetic Anomaly Detection (MAD-CAM)", Friday, October 23, 12:00pm, MH 606


Michael Larsen, Northrop Grumman


ABSTRACT: The Northrop Grumman Advanced PNT Systems (APS) is currently developing a new Compact Atomic Magnetometer for Magnetic Anomaly Detection (MAD-CAM) with applications to anti-submarine warfare, global navigation, planetary field mapping, etc. The system utilizes magnetic resonance to form a three axis vector magnetometer which is simultaneously capable of producing high accuracy whole field scalar measurements. This compact and integrated dual function magnetometer eliminates the need for separate scalar and vector magnetometers and leverages the stable properties of the atomic species to form a highly accurate and repeatable sensor with low noise, low drift, high bandwidth, and wide dynamic range.

NSD has leveraged the technological advancements made in developing its Nuclear Magnetic Resonance Gyroscope (NMRG) as part of the DARPA funded Navigation Grade Integrated Micro Gyro (NGIMG) program and extended that work to magnetometer development with an Internal Research and Development (IRAD) 2009-2014, and Contract Research and Development (CRAD) funding from 2010-2015. The resulting magnetometer system, like the NMRG, will have a low Size, Weight, and Power (SWaP). This presentation will show the basic concept of operation and system design, as well as shielded and unshielded prototype performanc. Applications of the MAD-CAM sensor to geolocation and INS aiding will be discussed, and the potential position resolution and geolocation accuracy presented.

"NANOGrav: A Galactic Scale Gravitational Wave Observatory", Friday, December 4, 12:00pm, MH 606


Joey Key, University of Texas

ABSTRACT: The North American Nanohertz Observatory for Gravitational Waves (NANOGrav) is a member of the International Pulsar Timing Array (IPTA), using pulsars to search for gravitational waves. NANOGrav scientists make use of some of the world's best telescopes and most advanced technology, drawing on physics, computer science, signal processing, and electrical engineering. Gravitational waves span many orders of magnitude in frequency, from the Hubble-length primordial waves that leave their imprint on the cosmic microwave background (CMB), to the gravitational waves with periods of years detectable by pulsar timing arrays (PTAs) like NANOGrav, the hour-long period waves detectable by space-based instruments such as eLISA, and the millisecond period waves detectable by ground-based interferometers like LIGO and Virgo. PTAs thus complement gravitational wave detectors in other frequency bands, accessing the gravitational wave very low frequency (VLF) band to probe supermassive binary black holes (SMBBHs), whose observations can be used to probe the innermost regions of merging galaxies and perhaps reveal the presence of other exotic phenomena.