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Abstract:

A new Beam Delivery System (BDS) has been developed to explore the feasibility of extending the energy reach of CLIC to 7 TeV, either through an extension of existing CLIC linacs or by integrating novel acceleration technologies. This study provides key insights for the design of future multiTeV collider concepts, including a potential 10 TeV plasma wakefield acceleration-based collider. Particular emphasis is placed on developing a more compact Final Focus System (FFS) capable of achieving a luminosity higher than that of previous designs. An in-depth analysis of higher-order optical aberrations and their impact on beam size and luminosity performance is presented.

Abstract:

Hydrodynamic optically-field-ionized (HOFI) plasma channels up to 100mm long are investigated. Optical guiding is demonstrated of laser pulses with a peak input intensity of $6\times10^{17}$ W cm$^{-2}$ through 100mm long plasma channels with on-axis densities measured interferometrically to be as low as $n_{e0} = (1.0\pm0.3)\times10^{17}$cm$^{-3}$. Guiding is also observed at lower axial densities, which are inferred from magneto-hydrodynamic simulations to be approximately $7\times10^{16}$cm$^{-3}$. Measurements of the power attenuation lengths of the channels are shown to be in good agreement with those calculated from the measured transverse electron density profiles. To our knowledge, the plasma channels investigated in this work are the longest, and have the lowest on-axis density, of any free-standing waveguide demonstrated to guide laser pulses with intensities above $>10^{17}$ W cm$^{-2}$.

Abstract:

The ATF extraction line laser-wire system has recently been upgraded allowing the measurement of micron scale transverse size electron beams. We report on the hardware upgrades, including focusing lens, laser and mechanical systems. First measurements using the new system from recent operation at the ATF in KEK are presented.