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University of New Hampshire

Theses/Dissertations

2004

Physics

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Beam Spin Asymmetry Measurements In Deeply Virtual Compton Scattering, Gagik Gavalian Jan 2004

Beam Spin Asymmetry Measurements In Deeply Virtual Compton Scattering, Gagik Gavalian

Doctoral Dissertations

Beam Spin Asymmetry (BSA) is studied in the Deeply Virtual Compton Scattering (DVCS) using CLAS detector at Jefferson Lab and longitudinally polarized electron beam with 4.8 GeV energy. This asymmetry is directly proportional to the imaginary part of the scattering amplitude, which relates it to the Generalized Parton distribution functions. Reaction ep → epX is studied. A fit to the line shape of the missing mass squared distribution of (ep) is used to extract the number of single photon final states in each kinematical bin for both helicities of the beam and for the helicity sum. DVCS beam spin asymmetry …


Sounding Rocket Measurements Of Thermal Electrons In Active Nightside Aurora, Elizabeth Macdonald Jan 2004

Sounding Rocket Measurements Of Thermal Electrons In Active Nightside Aurora, Elizabeth Macdonald

Doctoral Dissertations

On January 14th 2002 the SIERRA sounding rocket was launched from Poker Flat Research Range, Alaska into active substorm expansion aurora and reached 735 km. For the first time, direct measurements of the cold ionospheric population in darkness were made by the UNH Thermal Electron Detector (TED). At these middle altitudes, understanding this population is important because the thermal electrons can carry currents coupling the lower ionosphere and the magnetospheric auroral source. This thesis, focusing on the development and analysis of this new instrument, incorporates the study of two distinct areas. One area is the direct measurement of the ambient …


On The Rayleigh -Brillouin Scattering In Air, Qiuhua Zheng Jan 2004

On The Rayleigh -Brillouin Scattering In Air, Qiuhua Zheng

Doctoral Dissertations

GroundWinds lidar system is a high-spectral-resolution lidar system that can directly measure the Rayleigh-Brillouin scattering (RBS) spectra, from which the wind, temperature, and turbulence in the troposphere can be measured. Its transmitter is a double-frequency Nd-YAG laser at 532nm. Most of the data used in this research were taken on 31 July 2002.

A widely used mathematic model---the S6 model---is fitted to the measured RBS spectra. The discrepancies between the measured temperature from the RayleighBrillouin spectra and from the radiosonde, combined with the discrepancies between the model and the measured RBS spectra, indicate that there is room for the S6 …