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McKinsey, D. N.; Brome, C. R.; Butterworth, James; Dzhosyuk, S. N.; Huffman, P. R.; Mattoni, C. E. H.; Doyle, John M.; Golub, R.; Habicht, K.

doi:10.1103/physreva.59.200

Cited by 71 publications

(62 citation statements)

References 31 publications

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“…Excited atoms in singlet states also contribute to the prompt scintillation signal. The triplet-state molecule, He 2 (a 3 + u ), on the other hand, has a lifetime of * ito@lanl.gov ∼13 s in liquid helium [10,11]. In a high-excitation-density environment, however, the triplet-state excimers can also be destroyed through the Penning ionization process He * 2 + He * 2 → 3He + He + + e − ,…”

Section: Introductionmentioning

confidence: 99%

Effect of an electric field on superfluid helium scintillation produced byα-particle sources

et al. 2012

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We report a study of the intensity and time dependence of scintillation produced by weak α-particle sources in superfluid helium in the presence of an electric field (0-45 kV/cm) in the temperature range of 0.2 to 1.1 K at the saturated vapor pressure. Both the prompt and the delayed components of the scintillation exhibit a reduction in intensity with the application of an electric field. The reduction in the intensity of the prompt component is well approximated by a linear dependence on the electric field strength with a reduction of 15% at 45 kV/cm. When analyzed using the Kramers theory of columnar recombination, this electric field dependence leads to the conclusion that roughly 40% of the scintillation results from species formed from atoms originally promoted to excited states and 60% from excimers created by ionization and subsequent recombination with the charges initially having a cylindrical Gaussian distribution about the α track of 60 nm radius. The intensity of the delayed component of the scintillation has a stronger dependence on the electric field strength and on temperature. The implications of these data on the mechanisms affecting scintillation in liquid helium are discussed.

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Section: Introductionmentioning

confidence: 99%

Effect of an electric field on superfluid helium scintillation produced byα-particle sources

et al. 2012

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“…The background was determined by operating the experiment with the cold neutron component of the beam blocked by thin Cd and 6 Li doped plastic sheets, and was independent of heat input and relatively insensitive to the 3 He concentration. This background was largely due to long-lived molecular optical excitations in the superfluid bath [5] that were left over from the spallation radiation flash. In addition, the neutron beam intensity transmitted through the cell was measured with a 6 Li-doped glass scintillator detector, gated identically with the helium scintillation signal.…”

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confidence: 99%

Measurement of the ³ He mass diffusion coefficient in superfluid ⁴ He over the 0.45–0.95 K temperature range

et al. 2002

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“…The longer decay time for the triplet states renders them less useful for this purpose. The same number of photons emitted over 13 s [31] makes it impossible to distinguish the triplet events from backgrounds.…”

Section: Detection Of Decays In the Trapmentioning

confidence: 99%

Magnetic trapping of ultracold neutrons

et al. 2001

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Three-dimensional magnetic confinement of neutrons is reported. Neutrons are loaded into an Ioffe-type superconducting magnetic trap through inelastic scattering of cold neutrons with 4 He. Scattered neutrons with sufficiently low energy and in the appropriate spin state are confined by the magnetic field until they decay. The electron resulting from neutron decay produces scintillations in the liquid helium bath that results in a pulse of extreme ultraviolet light. This light is frequency downconverted to the visible and detected. Results are presented in which 500 ± 155 neutrons are magnetically trapped in each loading cycle, consistent with theoretical predictions. The lifetime of the observed signal, 660 s +290 −170 s, is consistent with the neutron beta-decay lifetime.

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Radiative decay of the metastableHe2(a3Σu

Cited by 71 publications

References 31 publications

Effect of an electric field on superfluid helium scintillation produced byα-particle sources

Effect of an electric field on superfluid helium scintillation produced byα-particle sources

Measurement of the ³ He mass diffusion coefficient in superfluid ⁴ He over the 0.45–0.95 K temperature range

Magnetic trapping of ultracold neutrons

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Radiative decay of the metastableHe2(a3Σu

Cited by 71 publications

References 31 publications

Effect of an electric field on superfluid helium scintillation produced byα-particle sources

Effect of an electric field on superfluid helium scintillation produced byα-particle sources

Measurement of the 3 He mass diffusion coefficient in superfluid 4 He over the 0.45–0.95 K temperature range

Magnetic trapping of ultracold neutrons

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Measurement of the ³ He mass diffusion coefficient in superfluid ⁴ He over the 0.45–0.95 K temperature range