R. Molnar | Searcharxiv

arXiv2026

Controlled kHz laser-driven electron irradiations for pre-clinical applications

We report the first in-air irradiations of biological samples with kHz laser-driven electrons with beam energy 20 MeV, high-energy tail extending to 40 MeV, and average dose rate up to 30 Gy/min. An in-house procedure has been developed to characterize and deliver on-demand (i.e. pre-agreed date and time) the target electron beam energy, dose and dose uniformity. We present a tolerance analysis on the laser electron parameters, highlighting the importance of beam stability for precise irradiations of in vivo zebrafish embryos and in vitro U251 glioblastoma cell line. The observed improvement in the survival rate of the zebrafish embryos, combined with unchanged cytotoxicity in the cell cultures, indicates promising results for normal tissue sparing while maintaining anticancer efficacy. The pre-clinical results of this work represent an important milestone towards the clinical translation of laser-plasma accelerators.

physics.med-ph↗

arXiv2010

Single-photon detectors based on ultra-narrow superconducting nanowires

Superconducting nanowire single-photon detectors (SNSPDs) perform single-photon counting with exceptional sensitivity and time resolution at near-infrared wavelengths. State-of-the-art SNSPDs, based on 100 nm-wide, 4 to 5 nm thick NbN nanowires, are vulnerable to constrictions, which significantly limit their yield. Also, their sensitivity becomes negligible beyond 2 \mu m wavelength, which makes them unsuitable for mid-infrared applications. SNSPDs based on few-tens-of-nanometer-wide nanowires are expected to efficiently detect mid-infrared photons and to operate at low bias currents, so constrictions may have less impact on their performance. Prior to this work, SNSPDs based on nanowires narrower than 50-nm had not been demonstrated because: (1) the SNSPD signal is roughly proportional to the nanowire width, so narrow nanowires have poor signal-to-noise ratio; and (2) fabrication at these length scales is extremely challenging. In this letter we report how we addressed these issues and demonstrated single-photon detection (20% detection efficiency at 1550 nm wavelength) with 30- and 20-nm-wide-nanowire detectors.

quant-ph↗