SearcharxivSearch

arXiv subjects

P. C. Samartzis

Publications and source records attributed to P. C. Samartzis.

2 recordsLinked to original sources

Highly spin-polarized deuterium atoms from the UV dissociation of Deuterium Iodide

We report the production of highly spin-polarized Deuterium atoms via photodissociation of deuterium iodide at 270 nm. The velocity distribution of both the deuterium and iodine photodissociation products is performed via velocity mapping slice-imaging. Additionally, the angular momentum polarization of the iodine products is studied using polarization-sensitive ionization schemes. The results are consistent with excitation of the $A^1Π_1$ state followed by adiabatic dissociation. The process produces $\sim$100\% electronically polarized deuterium atoms at the time of dissociation, which is then converted to $\sim 60\%$ nuclear D polarization after $\sim 1.6$ ns. These production times for hyperpolarized deuterium allow collision-limited densities of $\sim 10^{18}$ cm$^{-3}$, which is $\sim 10^6$ times higher than conventional (Stern-Gerlach separation) methods. We discuss how such high-density hyperpolarized deuterium atoms can be combined with laser fusion to measure polarized D-D fusion cross sections.

physics.chem-ph

Stark shift and parity non-conservation for near-degenerate states of xenon

We identify a pair of near-degenerate states of opposite parity in atomic Xe, the $5p^5 10s \,\, ^2[3/2]_2^o$ at $\rm{E}=94759.927$ cm$^{-1}$ and $5p^5 6f \,\, ^2[5/2]_2$ at $\rm{E}= 94759.935$ cm$^{-1}$, for which parity- and time-odd effects are expected to be enhanced by the small energy separation. We present theoretical calculations which indicate narrow widths for both states and we report a calculated value for the weak matrix element, arising from configuration mixing, of $|W|=2.1$ Hz for $^{132}$Xe. In addition, we measured the Stark effect of the $5p^5\,6f$ $^2[5/2]_{2}$ and $5p^5 \,6f \ ^2[3/2]_2$ ($\rm{E} =94737.121\,\rm{cm}^{-1}$) states. The Stark-shift of the $6f$ states is observed to be negative, revealing the presence of nearby $6g$ states at higher energies, which have not been observed before. The Stark-shift measurements imply an upper limit on the weak matrix element of $|W|\!<\!5$ Hz for the near-degenerate states ($10s \,\, ^2[3/2]_2^o$ and $6f \,\, ^2[5/2]_2$), which is in agreement with the presented calculations.

physics.atom-ph