Towards High-Efficiency Particle Detection Using Superconducting Microwire Arrays

TL;DR

This work addresses the need for high-efficiency, fast-timing detectors for charged-particle tracking in future accelerators. It characterizes an 8-channel SMSPD array built from a thicker 4.7 nm WSi film, achieving a fill-factor-normalized efficiency around 75% and timing near 130 ps across pixels, tested with 120 GeV hadrons and muons at the CERN SPS H6 beamline. A silicon tracking telescope provides ~10 μm spatial resolution, enabling precise in-situ efficiency measurements and the first SMSPD muon-detection results. The findings demonstrate a viable path toward high-efficiency SMSPD-based tracking with precision timing for next-generation facilities such as FCC-ee and Muon Collider.

Abstract

We present a detailed study of an 8-channel $1\times1$ mm$^{2}$ WSi superconducting microwire single photon detector (SMSPD) array exposed to 120 GeV hadron beam and 120 GeV muon beam at the CERN Super Proton Synchrotron H6 beamline. Following up on our first detailed characterization of the efficiency and response of an SMSPD fabricated on a 3 nm WSi film, we report measurements of enhanced particle detection efficiency using a sensor fabricated from a thicker 4.7nm-thick WSi film. We also report the first SMSPD detection efficiency measurement made for muons. Measurements are enabled by a silicon tracking telescope providing 10 $μ$m in-situ spatial resolution. The results show a fill factor-normalized detection efficiency of 75% and a time resolution of about 130 ps across pixels. These findings represent a significant advancement toward developing high-efficiency SMSPD charged particle tracking systems with simultaneous precision timing, with potential applications in future accelerator-based experiments such as the FCC-ee and Muon Collider.

Figures (8)

• Figure 1: A scanning electron micrograph of the meander structure of the sensor (left) and photograph of the SMSPD under study enclosed in a dark box attached to the cold plate in the cryostat (right).
• Figure 2: The bias current ($I_\text{bias}$) with respect to voltage across one of the SMSPD pixels ($V_\text{sense}$). The linear region in the middle is the region when the SMSPD is superconducting.
• Figure 3: A schematic diagram (top) and photograph (bottom) of the SMSPD under study and the reference instruments along the beamline.
• Figure 4: The average pulse shapes (left) from the MCP-PMT and pixel 7 of the SMSPD from triggered events are shown. The reconstructed amplitude distributions (right) from the pulse shapes of SMSPD pixel 7 for various bias currents are shown, where the peaks on the left are from baseline electronic noise and the peaks on the right are from signal pulses. The mean of the signal amplitude increases linearly with the bias current as expected.
• Figure 5: The time difference between the time of arrival of SMSPD pixel 7 signal (t$_\mathrm{SMSPD}$) and MCP-PMT signal (t$_\mathrm{MCP-PMT}$) is shown, demonstrating a $130\pm17$ ps time resolution ($\sigma$) of the SMSPD.