Collector-based measurement of gas desorption and secondary electron emission induced by 0–1.4 keV electrons from LHC-grade copper at 15 K

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68407700%3A21220%2F22%3A00360277" target="_blank" >RIV/68407700:21220/22:00360277 - isvavai.cz</a>

Výsledek na webu

<a href="https://doi.org/10.1016/j.nimb.2022.09.013" target="_blank" >https://doi.org/10.1016/j.nimb.2022.09.013</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.nimb.2022.09.013" target="_blank" >10.1016/j.nimb.2022.09.013</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Collector-based measurement of gas desorption and secondary electron emission induced by 0–1.4 keV electrons from LHC-grade copper at 15 K

Popis výsledku v původním jazyce

CERN’s Large Hadron Collider cryomagnets embed a 1.9 K UHV chamber lined with a 5 - 20 K beam-screen (BS) that intercepts the synchrotron radiation and electron cloud (EC). The low–energy EC irradiates the BS and desorbs gas, creating a dynamic vacuum effect. A novel setup controllably reproduces this by irradiating an unbaked as-received BS copper sample at 15 K with 0 - 1.4 keV electrons, representing a slice of the EC spectrum. This collector-based setup is qualified using a HOPG reference for secondary electron yield (SEY) and 15N2 as a tracer in low-energy electron stimulated desorption (ESD) measurements. Measurement at 15 K revealed sub-10 eV ESD thresholds and a maximum around 300 eV of 0.18 H2/e- and 0.13 CO/e-. Irradiation with 300 eV and 1 keV electrons at ~ 8.10-4 C.mm-2 conditioned ESD and SEY alike. Similar dose at 17 eV only caused minor SEY reduction and no ESD decline. The as-received H2 and CO2 yields at 300 eV decreased 5 - 150x between 15 and 265 K, respectively.

Název v anglickém jazyce

Collector-based measurement of gas desorption and secondary electron emission induced by 0–1.4 keV electrons from LHC-grade copper at 15 K

Popis výsledku anglicky

CERN’s Large Hadron Collider cryomagnets embed a 1.9 K UHV chamber lined with a 5 - 20 K beam-screen (BS) that intercepts the synchrotron radiation and electron cloud (EC). The low–energy EC irradiates the BS and desorbs gas, creating a dynamic vacuum effect. A novel setup controllably reproduces this by irradiating an unbaked as-received BS copper sample at 15 K with 0 - 1.4 keV electrons, representing a slice of the EC spectrum. This collector-based setup is qualified using a HOPG reference for secondary electron yield (SEY) and 15N2 as a tracer in low-energy electron stimulated desorption (ESD) measurements. Measurement at 15 K revealed sub-10 eV ESD thresholds and a maximum around 300 eV of 0.18 H2/e- and 0.13 CO/e-. Irradiation with 300 eV and 1 keV electrons at ~ 8.10-4 C.mm-2 conditioned ESD and SEY alike. Similar dose at 17 eV only caused minor SEY reduction and no ESD decline. The as-received H2 and CO2 yields at 300 eV decreased 5 - 150x between 15 and 265 K, respectively.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10302 - Condensed matter physics (including formerly solid state physics, supercond.)

Projekt

—

Návaznosti

S - Specificky vyzkum na vysokych skolach

Rok uplatnění

2022

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Nuclear Instruments and Methods in Physics Research, Section B, Beam Interactions with Materials and Atoms

ISSN

0168-583X

e-ISSN

1872-9584

Svazek periodika

531

Číslo periodika v rámci svazku

november

Stát vydavatele periodika

NL - Nizozemsko

Počet stran výsledku

10

Strana od-do

34-43

Kód UT WoS článku

000868577600004

EID výsledku v databázi Scopus

2-s2.0-85139018510