The large COMPASS polarized solid ammonia target for Drell-Yan measurements with a pion beam

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68081731%3A_____%2F22%3A00556655" target="_blank" >RIV/68081731:_____/22:00556655 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/00216208:11320/22:10441078 RIV/00216208:11320/22:10458277

Výsledek na webu

<a href="https://www.sciencedirect.com/science/article/pii/S0168900221009918" target="_blank" >https://www.sciencedirect.com/science/article/pii/S0168900221009918</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.nima.2021.166069" target="_blank" >10.1016/j.nima.2021.166069</a>

Jazyk výsledku

angličtina

Název v původním jazyce

The large COMPASS polarized solid ammonia target for Drell-Yan measurements with a pion beam

Popis výsledku v původním jazyce

The transversely polarized target (PT) of the COMPASS (NA58) collaboration at CERN has been used for Drell-Yan measurements in 2015 and 2018. The transverse spin structure of the proton has been studied using a negative pion beam and a solid ammonia target. Employing the dynamic nuclear polarization (DNP) method, proton polarization values of more than 80% have been routinely achieved after one day, at a homogeneous magnetic field of 2.5 T and using a He-3/He-4 dilution refrigerator. During the data-taking the target operates in a transversely oriented magnetic dipole field at 0.6 T. This so-called frozen spin operation mode without the DNP pumping process leads to a slow depolarization of the target material, which is further accelerated by the heat input of the pion beam, produced secondary particles and radiation damage effects to the target material. Ammonia has the highest resistance against radiation-induced depolarization among known solid target materials. The proton polarization has been measured by the nuclear magnetic resonance (NMR). Relaxation times of about 1100 h have been observed for the proton polarization resulting in an average polarization between 68% and 76% during about two weeks long data-taking periods. To achieve a systematic uncertainty of the polarization Delta P/P as low as 3.2% and a statistical one of less than 1.8% two large target cells with appropriate positioning of the NMR-coils have been built.

Název v anglickém jazyce

The large COMPASS polarized solid ammonia target for Drell-Yan measurements with a pion beam

Popis výsledku anglicky

The transversely polarized target (PT) of the COMPASS (NA58) collaboration at CERN has been used for Drell-Yan measurements in 2015 and 2018. The transverse spin structure of the proton has been studied using a negative pion beam and a solid ammonia target. Employing the dynamic nuclear polarization (DNP) method, proton polarization values of more than 80% have been routinely achieved after one day, at a homogeneous magnetic field of 2.5 T and using a He-3/He-4 dilution refrigerator. During the data-taking the target operates in a transversely oriented magnetic dipole field at 0.6 T. This so-called frozen spin operation mode without the DNP pumping process leads to a slow depolarization of the target material, which is further accelerated by the heat input of the pion beam, produced secondary particles and radiation damage effects to the target material. Ammonia has the highest resistance against radiation-induced depolarization among known solid target materials. The proton polarization has been measured by the nuclear magnetic resonance (NMR). Relaxation times of about 1100 h have been observed for the proton polarization resulting in an average polarization between 68% and 76% during about two weeks long data-taking periods. To achieve a systematic uncertainty of the polarization Delta P/P as low as 3.2% and a statistical one of less than 1.8% two large target cells with appropriate positioning of the NMR-coils have been built.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10303 - Particles and field physics

Projekt

Výsledek vznikl pri realizaci vícero projektů. Více informací v záložce Projekty.

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2022

Kód důvěrnosti údajů

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

Název periodika

Nuclear Instruments & Methods in Physics Research Section A

ISSN

0168-9002

e-ISSN

1872-9576

Svazek periodika

1025

Číslo periodika v rámci svazku

11 February

Stát vydavatele periodika

NL - Nizozemsko

Počet stran výsledku

10

Strana od-do

166069

Kód UT WoS článku

000777573700004

EID výsledku v databázi Scopus

2-s2.0-85121588847