CHARACTERISTICS OF CONDENSED GAS MODERATORS FOR THE GENERATION OF VERY SLOW POLARIZED MUONS

Citation
E. Morenzoni et al., CHARACTERISTICS OF CONDENSED GAS MODERATORS FOR THE GENERATION OF VERY SLOW POLARIZED MUONS, Journal of applied physics, 81(8), 1997, pp. 3340-3347
Citations number
27
Categorie Soggetti
Physics, Applied
Journal title
ISSN journal
00218979
Volume
81
Issue
8
Year of publication
1997
Part
1
Pages
3340 - 3347
Database
ISI
SICI code
0021-8979(1997)81:8<3340:COCGMF>2.0.ZU;2-4
Abstract
Motivated by the possibility of using condensed gas moderators to prod uce very slow (epithermal) polarized muons we have studied the moderat or properties of rare gas solids and solid N-2 thin films as a functio n of the growing parameters (deposition temperature and rate, heat tre atment) and of the film thickness. For Ar and Kt moderators the modera tion efficiency is found to depend an the growth temperature and an an nealing effect is observed. The dependence can be interpreted in terms of the changes in granularity and porosity of I-he condensed gas laye rs when the growth parameters are varied. From the thickness dependenc e of the moderation efficiency the escape depth, of the very slow muon s was determined, Its large value;indicates a suppression of electroni c energy loss mechanisms for the epithermal muons. The rime dependent decay properties of the moderators were also investigated and found to depend solely on the rest gas pressure. At a pressure of 10(-10) mbar the moderation efficiency remains stable over a period of days. (C) 1 997 American Institute of Physics.