Experimental measurement of ultracold neutron production in superfluid 4He

Baker, C.A.; Balashov, S.; Butterworth, James; Geltenbort, P.; Green, K.; Harris, Philip; Grinten, M. G. D. van der; Iaydjiev, P.; Иванов, С. Н.; Pendlebury, J.M.; Shiers, D.; Tucker, M. A. H.; Yoshiki, H.

doi:10.1016/s0375-9601(02)01773-5

Cited by 74 publications

(56 citation statements)

References 9 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The present experiments were complemented by a time-of-flight (TOF) measurement of the incident cold neutron beam to enable a better comparison with the theoretical UCN production rate. As in prior experiments performed by other groups [20,21,29,30], we found the UCN production rate to agree reasonably well with the theoretical expectation.…”

Section: Introductionsupporting

confidence: 91%

See 1 more Smart Citation

Ultracold neutrons extracted from a superfluid-helium converter coated with fluorinated grease

et al. 2010

View full text Add to dashboard Cite

We report experiments on the production of ultracold neutrons (UCN) in a converter of superfluid helium coated with fluorinated grease (fomblin). We employed our special technique of window-free extraction of accumulated UCN from the superfluid helium, in which they were produced by downscattering neutrons of a cold beam from the Munich research reactor. The fomblin-coating reduced the time constant for UCN passage through the extraction hole by a factor three compared to our previous experiment employing an uncoated stainless steel vessel. A time-of-flight measurement of the cold neutron spectrum incident on the converter, combined with a gold foil activation, allowed us to determine both the single-phonon and multi-phonon contributions to the UCN production. The UCN production rate is in reasonable agreement with the theoretical expectation.

show abstract

Section: Introductionsupporting

confidence: 91%

“…The most intense source for user experiments with UCN, at the Institut Laue Langevin in Grenoble [15], provides UCN densities not exceeding a few 10 per cm 3 . In order to improve counting statistical accuracy of experiments, new UCN sources are being developed in many laboratories around the world [16][17][18][19][20][21][22].…”

Section: Introductionmentioning

confidence: 99%

Ultracold neutrons extracted from a superfluid-helium converter coated with fluorinated grease

et al. 2010

View full text Add to dashboard Cite

show abstract

“…UCN production via this superthermal mechanism has been demonstrated [1006], and the solid-state UCN detectors developed by the collaboration have also been shown to work well [1007]. At the time of writing, there are still some hardware problems to be resolved, in particular with components in and around the Ramsey measurement chamber.…”

Section: Ill Cryoedm Experiments Statusmentioning

confidence: 99%

Flavor physics of leptons and dipole moments

Raidal¹,

Schaaf²,

Bigi³

et al. 2009

Flavor in the Era of the LHC

View full text Add to dashboard Cite

This chapter of the report of the "Flavour in the era of the LHC" Workshop discusses the theoretical, phenomenological and experimental issues related to flavour phenomena in the charged lepton sector and in flavour-conserving CP-violating processes. We review the current experimental limits and the main theoretical models for the flavour structure of fundamental particles. We analyze the phenomenological consequences of the available data, setting constraints on explicit models beyond the Standard Model, presenting benchmarks for the discovery potential of forthcoming measurements both at the LHC and at low energy, and exploring options for possible future experiments.

show abstract

“…Current projects to increase the density of UCNs for physics experiments employ neutron converters of superfluid helium (He-II) [15][16][17][18][19][20] and solid deuterium [21][22][23][24][25][26]. They exploit the concept of a superthermal source [27], where the converter temperature can be much higher than the UCN "temperature."…”

Section: Introductionmentioning

confidence: 99%

“…In He-II the main contribution to UCN production is due to single-phonon excitations (see [17] for a separation of UCN production in single-and multiphonon contributions), which occur at the crossing point λ * of the dispersion relations of the free neutron and of He-II. At saturated vapor pressure (SVP), λ * = 8.92(2)Å (derived from the data in Ref.…”

Section: Introductionmentioning

confidence: 99%

Experimental study of ultracold neutron production in pressurized superfluid helium

et al. 2015

View full text Add to dashboard Cite

We investigate experimentally the pressure dependence of the production of ultracold neutrons (UCNs) in superfluid helium in the range from saturated vapor pressure to 20 bar. A neutron velocity selector allows the separation of underlying single-phonon and multiphonon processes by varying the incident cold neutron (CN) wavelength in the range from 3.5 to 10Å. The predicted pressure dependence of UCN production derived from inelastic neutron scattering data is confirmed for the single-phonon excitation. For multiphonon-based UCN production we found no significant dependence on pressure, whereas calculations from inelastic neutron scattering data predict an increase of 43(6)% at 20 bar relative to saturated vapor pressure. From our data we conclude that applying pressure to superfluid helium does not increase the overall UCN production rate at a typical CN guide.

show abstract

Experimental measurement of ultracold neutron production in superfluid 4He

Cited by 74 publications

References 9 publications

Ultracold neutrons extracted from a superfluid-helium converter coated with fluorinated grease

Ultracold neutrons extracted from a superfluid-helium converter coated with fluorinated grease

Flavor physics of leptons and dipole moments

Experimental study of ultracold neutron production in pressurized superfluid helium

Contact Info

Product

Resources

About