Does Quantum Mechanical Tunneling Affect the Validity of Hole Volume Distributions Obtained from Positron Annihilation Lifetime Measurements?

Baugher, A. H.; Kossler, W. J.; Petzinger, K. G.

doi:10.1021/ma960756b

Cited by 34 publications

(29 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This assumption is confirmed by calculations which showed that the Ps will exist in the hole where it is formed or first trapped until annihilation (Anderson localization) [37,38]. That means that the o-Ps lifetime mirrors the hole size at the moment of annihilation and in that way the fluctuating free volume of a liquid [27,28,31].…”

Section: Introductionmentioning

confidence: 71%

Fluctuation approach for the estimation of the dynamic heterogeneity in glass-forming liquids from the dispersion in o-Ps lifetimes: Free volume fluctuations in polymers

Dlubek

2006

Journal of Non-Crystalline Solids

View full text Add to dashboard Cite

Section: Introductionmentioning

confidence: 71%

Fluctuation approach for the estimation of the dynamic heterogeneity in glass-forming liquids from the dispersion in o-Ps lifetimes: Free volume fluctuations in polymers

Dlubek

2006

Journal of Non-Crystalline Solids

View full text Add to dashboard Cite

“…A hot Ps interacting with the lattice can easily emit phonons producing variations of on-site energy δV associated with vibration of the box. If δV /BW >> 1 (where BW is the bandwidth) Ps localizes [30]. Only when Ps has dissipated all its energy to emit phonons such as δV > BW its migration can be wavelike (in our case BW ≃ 0.2 eV for the lowest band).…”

mentioning

confidence: 88%

Positronium emission spectra from self-assembled metal-organic frameworks

et al. 2014

View full text Add to dashboard Cite

Recently, evidence for positronium (Ps) in a Bloch state in self-assembled metal-organic frameworks (MOFs) has been reported [Dutta et al., Phys. Rev. Lett. 110, 197403 (2013)]. In this paper, we study Ps emission into vacuum from four different MOF crystals: MOF-5, IRMOF-8, ZnO4(FMA)3 and IRMOF-20. Our measurements of Ps yield and emission energy into vacuum provide definitive evidence of Ps delocalization. We determine with a different technique Ps diffusion lengths in agreement with the recently published results. Furthermore, we measure that a fraction of the Ps is emitted into vacuum with a distinctly smaller energy than what one would expect for Ps localized in the MOFs' cells. We show that a calculation assuming Ps delocalized in a Kronig-Penney potential reproduces the measured Ps emission energy.

show abstract

“…The process of quantum confinement is advantageous for such experiments because tunneling Ps becomes localized in a subset of the pore structure, and the effective density of Ps is increased [290]. Similarly, tunneling rates between different accessible pores may have to be taken into account in porosity measurements using lifetime measurements [291,292]. One may also study Ps-gas interactions within such structures via annihilation radiation [293][294][295], including aerogels [296][297][298], and using laser spectroscopy it is also possible to study the effects of Ps confinement directly [115].…”

Section: Ps Productionmentioning

confidence: 99%

Experimental progress in positronium laser physics

2018

View full text Add to dashboard Cite

Abstract. The field of experimental positronium physics has advanced significantly in the last few decades, with new areas of research driven by the development of techniques for trapping and manipulating positrons using Surko-type buffer gas traps. Large numbers of positrons (typically ≥10 6 ) accumulated in such a device may be ejected all at once, so as to generate an intense pulse. Standard bunching techniques can produce pulses with ns (mm) temporal (spatial) beam profiles. These pulses can be converted into a dilute Ps gas in vacuum with densities on the order of 10 7 cm −3 which can be probed by standard ns pulsed laser systems. This allows for the efficient production of excited Ps states, including long-lived Rydberg states, which in turn facilitates numerous experimental programs, such as precision optical and microwave spectroscopy of Ps, the application of Stark deceleration methods to guide, decelerate and focus Rydberg Ps beams, and studies of the interactions of such beams with other atomic and molecular species. These methods are also applicable to antihydrogen production and spectroscopic studies of energy levels and resonances in positronium ions and molecules. A summary of recent progress in this area will be given, with the objective of providing an overview of the field as it currently exists, and a brief discussion of some future directions.

show abstract

Does Quantum Mechanical Tunneling Affect the Validity of Hole Volume Distributions Obtained from Positron Annihilation Lifetime Measurements?

Cited by 34 publications

References 7 publications

Fluctuation approach for the estimation of the dynamic heterogeneity in glass-forming liquids from the dispersion in o-Ps lifetimes: Free volume fluctuations in polymers

Fluctuation approach for the estimation of the dynamic heterogeneity in glass-forming liquids from the dispersion in o-Ps lifetimes: Free volume fluctuations in polymers

Positronium emission spectra from self-assembled metal-organic frameworks

Experimental progress in positronium laser physics

Contact Info

Product

Resources

About