High-yield thermalized positronium at room temperature emitted by morphologically tuned nanochanneled silicon targets

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68407700%3A21340%2F21%3A00351573" target="_blank" >RIV/68407700:21340/21:00351573 - isvavai.cz</a>

Výsledek na webu

<a href="https://doi.org/10.1088/1361-6455/abf6b6" target="_blank" >https://doi.org/10.1088/1361-6455/abf6b6</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1088/1361-6455/abf6b6" target="_blank" >10.1088/1361-6455/abf6b6</a>

Jazyk výsledku

angličtina

Název v původním jazyce

High-yield thermalized positronium at room temperature emitted by morphologically tuned nanochanneled silicon targets

Popis výsledku v původním jazyce

Nanochanneled silicon targets with high positron/positronium (Ps) conversion rate and efficient Ps cooling were produced. Morphological parameters of the nanochannels, such as their diameter and length, were adjusted to get a large fraction of thermalized Ps at room temperature being emitted into vacuum. Ps cooling measurements were conducted combining single-shot positron annihilation lifetime spectroscopy and Doppler spectroscopy of the 1(3)S -> 2(3)P transition. 2 gamma-3 gamma annihilation ratio measurements were also performed to estimate the positron/Ps conversion efficiency. In a converter with nanochannel diameter of 7-10 nm and depth of 3.89 mu m, similar to 28% of implanted positrons with an energy of 3.3 keV was found to be emitted as Ps with a transverse kinetic energy of 11 +/- 2 meV. The reduction of the nanochannels depth to 1.13 mu m, without changing the nanochannel diameter, was found to result in a less efficient cooling, highlighting the presence of Ps reflection from the bottom end of nanochannels.

Název v anglickém jazyce

High-yield thermalized positronium at room temperature emitted by morphologically tuned nanochanneled silicon targets

Popis výsledku anglicky

Nanochanneled silicon targets with high positron/positronium (Ps) conversion rate and efficient Ps cooling were produced. Morphological parameters of the nanochannels, such as their diameter and length, were adjusted to get a large fraction of thermalized Ps at room temperature being emitted into vacuum. Ps cooling measurements were conducted combining single-shot positron annihilation lifetime spectroscopy and Doppler spectroscopy of the 1(3)S -> 2(3)P transition. 2 gamma-3 gamma annihilation ratio measurements were also performed to estimate the positron/Ps conversion efficiency. In a converter with nanochannel diameter of 7-10 nm and depth of 3.89 mu m, similar to 28% of implanted positrons with an energy of 3.3 keV was found to be emitted as Ps with a transverse kinetic energy of 11 +/- 2 meV. The reduction of the nanochannels depth to 1.13 mu m, without changing the nanochannel diameter, was found to result in a less efficient cooling, highlighting the presence of Ps reflection from the bottom end of nanochannels.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10301 - Atomic, molecular and chemical physics (physics of atoms and molecules including collision, interaction with radiation, magnetic resonances, Mössbauer effect)

Projekt

<a href="/cs/project/LM2015058" target="_blank" >LM2015058: Výzkumná infrastruktura pro experimenty v CERN</a><br>

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2021

Kód důvěrnosti údajů

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

Název periodika

Journal of Physics B: Atomic, Molecular and Optical Physics

ISSN

0953-4075

e-ISSN

1361-6455

Svazek periodika

54

Číslo periodika v rámci svazku

8

Stát vydavatele periodika

GB - Spojené království Velké Británie a Severního Irska

Počet stran výsledku

11

Strana od-do

—

Kód UT WoS článku

000648710700001

EID výsledku v databázi Scopus

2-s2.0-85106280191