Submicrometer transverse positioning of micromachined targets in high-intensity laser experiments

Demonstrate submicrometer-accuracy transverse positioning capability for target delivery systems of micromachined targets mounted on wafers or small chips, suitable for irradiation of micrometric bar targets at repetition rates beyond sub-Hz.

Background

Because µ-bar targets are comparable to the laser focus dimensions, precise transverse positioning is critical to avoid intensity drops from pointing instability. While high-rate replenishing systems exist for other target types (e.g., rotating disks, tapes, and various jets), current systems for micromachined targets operate at sub-Hz and lack demonstrated submicrometer positioning accuracy.

Establishing reliable submicrometer alignment for these targets would enable higher repetition-rate experiments and reduce shot-to-shot variability, directly affecting the practical deployment of the proposed enhanced TNSA scheme.

References

Second, while proton production targets in the form of massive rotating disks, spooled tape, and jets of liquids, gases, and molecular clusters demonstrated target replenishment with Hz -- kHz rates, systems designed to deliver micromachined targets mounted on either whole wafers or small chips operate at sub-Hz rates only and their ability to position targets with submicrometer accuracy in the transverse direction has yet to be demonstrated.

— Ion acceleration from micrometric targets immersed in an intense laser field  (2404.11135 - Elkind et al., 2024) in Discussion, Practical aspects