Search NASA⌕ Search
Home/Archive/DOE OSTI

DOE OSTI · 1676389

A cantilevered liquid-nitrogen-cooled silicon mirror for the Advanced Light Source Upgrade

Cutler, Grant·Cocco, Daniele·DiMasi, Elaine·Morton, Simon·Sanchez del Rio, Manuel·Padmore, Howard
View original source ↗Read source document ↗Export metadata ↓

Abstract

This paper presents a novel cantilevered liquid-nitrogen-cooled silicon mirror design for the first optic in a new soft X-ray beamline that is being developed as part of the Advanced Light Source Upgrade (ALS-U) (Lawrence Berkeley National Laboratory, USA). The beamline is optimized for photon energies between 400 and 1400 eV with full polarization control. Calculations indicate that, without correction, this design will achieve a Strehl ratio greater than 0.85 for the entire energy and polarization ranges of the beamline. With a correction achieved by moving the focus 7.5 mm upstream, the minimum Strehl ratio is 0.99. This design is currently the baseline plan for all new ALS-U insertion device beamlines.

Explore related subjects

47 OTHER INSTRUMENTATIONcantilevered mirrorscryogenicshigh heat-loadliquid-nitrogen coolingsilicon mirrorswavefront propagation

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Cutler, Grant, Cocco, Daniele, DiMasi, Elaine, Morton, Simon, Sanchez del Rio, Manuel, Padmore, Howard. 2020-08-11. A cantilevered liquid-nitrogen-cooled silicon mirror for the Advanced Light Source Upgrade. https://doi.org/10.1107/s1600577520008930

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related reports

DOE OSTI2026

High Multiplicity Trigger for long-lived particles in CMS detector

Searches for long-lived particles (LLPs) at the CMS experiment often involve unconventional event topologies that are difficult to efficiently select using standard trigger strategies. To improve sensitivity to such signatures during LHC Run 3 operation, a dedicated High Multiplicity Trigger (HMT) has been developed and deployed in the CMS trigger system. The trigger targets events containing unusually large numbers of hits in the CMS cathode strip chamber (CSC) muon detectors, a characteristic signature of several LLP scenarios involving displaced decays in the muon system. The HMT implementation, trigger logic, rate dependence with pileup, and operational stability are described. Optimized hit multiplicity thresholds are used to maintain acceptable trigger rates under high-luminosity and high-pileup conditions while preserving high efficiency across a broad range of LLP lifetimes and kinematic regimes. The trigger performance is evaluated using both simulated event samples and proton-proton collision data collected during Run 3 of the LHC. The HMT substantially extends the CMS sensitivity to non-standard signatures associated with LLP decays and provides a flexible platform for future searches for physics beyond the Standard Model.

47 OTHER INSTRUMENTATION↗