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<p><span>Theory Center Seminar <br>
Monday, Dec. 12, 2016<br>
1:00 p.m. (coffee at 12:45 p.m.)<br>
CEBAF Center, Room L102<br>
<b><br>
Yoshitaka Taira <br>
AIST Tsukuba<br>
<br>
</b></span><b><span>Gamma-ray Vortex Generation by Inverse
Compton Scattering</span></b><br>
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<div>In this talk, I will present a development of a gamma-ray
vortex using an inverse Compton scattering (ICS). </div>
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<div>The vortex beam forms a helical wave front along the direction
of propagation and carries discrete values m hbar</div>
<div> of orbital angular momentum (OAM) per photon. Fundamental and
applied research on optical vortices using visible </div>
<div>wavelength lasers is ongoing. However, vortex beams are not
limited to visible light but include the sub-MeV </div>
<div>electron vortex, ~ 10 keV X-ray vortex, terahertz wave vortex,
and cold neutron vortex. ICS of a laser photon </div>
<div>by a relativistic electron is one of the promising technique to
generate the gamma-ray vortex in the MeV and GeV</div>
<div>range. Gamma-ray vortex providing an additional degree of
freedom will open new research opportunities to the </div>
<div>nuclear physics. Characteristics of the gamma-ray vortices
generated via two different ICS methods and basic </div>
experiments of the optical vortex laser generated by a holographic
grating will be presented. <br>
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