Positronium fractions and cavity sizes derived from 1-and 2-detector Doppler broadening spectra

被引：8

作者：

García, AA ^{[1
]}

Siebbeles, LDA ^{[1
]}

Rivera, A ^{[1
]}

Schut, H ^{[1
]}

Eijt, SWH ^{[1
]}

Galindo, RE ^{[1
]}

van Veen, A ^{[1
]}

机构：

[1] Delft Univ Technol, Interfac Reactor Inst IRI, NL-2629 JB Delft, Netherlands

来源：

POSITRON ANNIHILATION - ICPA-12 | 2001年 / 363-3卷

关键词：

2-detector; Doppler broadening; free volume; positrons; positronium;

D O I：

10.4028/www.scientific.net/MSF.363-365.287

中图分类号：

TH7 [仪器、仪表];

学科分类号：

0804 ; 080401 ; 081102 ;

摘要：

The Doppler broadening (DB) of positron annihilation radiation in polyethylene, teflon and silica is presented and compared with results from positron lifetime experiments. Conventional DB measurements and two detector coincidence measurements were performed. The DB spectra could be fitted to a sum of three Gaussians where the narrowest component is attributed to annihilation of p-Ps. The size of the cavities is estimated by comparing the spectra with the calculated momentum distribution of Ps in an infinite spherical well. The estimated cavity sizes derived this way are somewhat larger than those obtained from lifetime results. The deduced o-PS intensities are in agreement with lifetime results.

引用

页码：287 / 289

页数：3

共 9 条

[1] VACANCY-TYPE DEFECTS IN CRYSTALLINE AND AMORPHOUS SIO2 [J].

DANNEFAER, S ;

BRETAGNON, T ;

KERR, D .

JOURNAL OF APPLIED PHYSICS, 1993, 74 (02) :884-890

[2]

DEVRIES J, 1987, THESIS NETHERLANDS

[3] Positron states in polyethylene and polytetrafluoroethylene: A positron lifetime and Doppler-broadening study [J].

Dlubek, G ;

Saarinen, K ;

Fretwell, HM .

NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS, 1998, 142 (1-2) :139-155

[4] Vacancy spectroscopy of radiation cross-linked and degraded polytetrafluoroethylenes [J].

Ito, Y ;

Mohamed, HFM ;

Seguchi, T ;

Oshima, A .

RADIATION PHYSICS AND CHEMISTRY, 1996, 48 (06) :775-779

[5] PROGRAM SYSTEM FOR ANALYZING POSITRON LIFETIME SPECTRA AND ANGULAR-CORRELATION CURVES [J].

KIRKEGAARD, P ;

ELDRUP, M ;

MOGENSEN, OE ;

PEDERSEN, NJ .

COMPUTER PHYSICS COMMUNICATIONS, 1981, 23 (03) :307-335

[6]

NAKANISHI H, 1988, STUDIES PHYSICAL THE, V57, P159

[7]

Schut H., 1990, Ph.D. thesis.

[8] POSITRON-ANNIHILATION IN IRRADIATED AND UNIRRADIATED POLYETHYLENES [J].

SUZUKI, T ;

OKI, Y ;

NUMAJIRI, M ;

MIURA, T ;

KONDO, K ;

ITO, Y .

JOURNAL OF POLYMER SCIENCE PART B-POLYMER PHYSICS, 1992, 30 (06) :517-525

[9] VEPFIT APPLIED TO DEPTH PROFILING PROBLEMS [J].

VANVEEN, A ;

SCHUT, H ;

CLEMENT, M ;

DENIJS, JMM ;

KRUSEMAN, A ;

IJPMA, MR .

APPLIED SURFACE SCIENCE, 1995, 85 (1-4) :216-224

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