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A new, versatile Thomson parabola ion energy (TPIE) analyzer has been designed, constructed, and used at the OMEGA-EP facility. Laser-accelerated multi-MeV ions from hemispherical C targets are transmitted through a W pinhole into a multi-kG magnetic field and subsequently through a parallel electric field of up to 25 kV/cm. The ion drift region has a user-selected length of 10, 50, or 80 cm. With the highest fields, 400-MeV C(6+) and C(5+) may be resolved. TPIE is ten-inch manipulator (TIM)-mounted at OMEGA-EP and can be used opposite either of the EP ps beams. The instrument runs on pressure-interlocked 15-Vdc power available in EP TIM carts. Flux control derives from the insertion depth into the target chamber and the user-selected pinhole dimensions. The detector consists of CR39 backed by an image plate. A fully relativistic simulation code for calculating ion trajectories was employed for design optimization. Excellent agreement of code predictions with the actual ion positions on the detectors is observed. Through pit counting of carbon-ion tracks in CR39, it is shown that conversion efficiency of laser light to energetic carbon ions exceeds ~5% for these targets.

Single-pulse energy measurements of the Xe(L) emission induced by femtosecond multiphoton ultraviolet (248 nm) excitation of Xe clusters have been made with a transmission grating spectrograph equipped with a calibrated x-ray CCD camera. On the basis of the observed magnitude of the Xe(L) single-pulse yield and the morphology measured by Thomson scattering of the self-trapped channels guiding the incident 248 nm pulse, it is concluded that the coupling strength for x-ray production from the clusters cannot be accounted for by an interaction involving only independent single-electron processes. Analysis indicates that the coupling requires augmentation by a factor of . This conclusion is in good agreement with an independent spectral study involving the direct comparison of the multiphoton coupling strength with electron collisional data for Xe obtained from EBIT studies, an analysis which placed the corresponding factor of augmentation of the coupling in the interval . These findings are consistent with estimates of the magnitude of the strengthened coupling which could arise from the development of ordered multi-electron motions.

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