Search
Now showing items 1-10 of 70
Studies of intrinsic properties of gamma ray bursts detected by the HETE-II satellite
(Massachusetts Institute of Technology, 2007)
Analysis of HETE-II data is discussed with the aim of understanding the intrinsic properties of gamma-ray bursts (GRBs). A technique is developed that allows the simultaneous estimation of source and background counts ...
Alcator C-Mod soft X-ray pulse height analysis system
(Massachusetts Institute of Technology, 2007)
A pulse height analysis (PHA) system has been installed on the Alcator C-Mod magnetic confinement fusion experiment. The PHA utilizes a Si(Li) detector to measure soft X-rays in the 1-30 keV range with an energy resolution ...
Investigation of thermal filamentation instability over Gakona, Alaska
(Massachusetts Institute of Technology, 2007)
The thermal filamentation instability has been invoked to explain the formation of parallel plate waveguides in mid-latitude ionospheric plasmas during Arecibo, Puerto Rico heating experiments in 1997. The geometry of the ...
An attempt to measure the time delays of three gravitational lenses
(Massachusetts Institute of Technology, 2007)
I present the results of reduction and analysis of two seasons of gravitational lens monitoring using the Very Large Array (VLA) at 8.5 GHz. The campaign monitored five gravitational lenses, GL1608, GL1830, GL1632, GL1838, ...
Scanning tunneling spectroscopy of lead-substituted bismuth strontium copper oxide
(Massachusetts Institute of Technology, 2007)
The hole-doped cuprate Bi ... is doped with lead to the solubility limit of x = 0.38 and studied using STM/STS in the overdoped regime where Tc < 2K. Despite the high lead content, residual supermodulations are observed ...
Imaging the two gaps of the high temperature superconductor Pb-Bi₂Sr₂CuO₆₊x
(Massachusetts Institute of Technology, 2007)
The nature and behavior of electronic states in high temperature superconductors are the center of much debate. The pseudogap state, observed above the superconducting transition temperature Tc, is seen by some as a precursor ...
Active materials in photonic crystals
(Massachusetts Institute of Technology, 2007)
I analyze new phenomena arising from embedding active materials inside of photonic crystal structures. These structures strongly modify the photonic local density of states (LDOS), leading to quantitative and qualitative ...
Feedback regulation in gene networks
(Massachusetts Institute of Technology, 2007)
Cellular genetic information is encoded in DNA. The passage of this information from DNA to proteins is regulated at multiple levels and each level gives cells the chance to control the structure and function of their ...
X-ray timing of the accreting millisecond pulsar SAX J1808.4-3658
(Massachusetts Institute of Technology, 2007)
We present a 7 yr timing study of the 2.5 ms X-ray pulsar SAX J1808.4-3658, an X-ray transient with a recurrence time of =2 yr, using data from the Rossi X-ray Timing Explorer covering 4 transient outbursts (1998-2005). ...
Elastic and inelastic X-ray scattering studies of the low dimensional spin-1/2 quantum magnet TiOCl
(Massachusetts Institute of Technology, 2007)
The ground state for a one dimensional spin 1/2 Heisenberg chain coupled to phonons is a dimerized singlet state known as a "spin-Peierls" state. Currently, the spin-Peierls state is realized in only a handful of known ...