1
|
Chernyavsky SM, Dubois M, Korobkina E, Lychagin EV, Muzychka AY, Nekhaev GV, Nesvizhevsky VV, Nezvanov AY, Strelkov AV, Zhernenkov KN. Enhanced directional extraction of very cold neutrons using a diamond nanoparticle powder reflector. Rev Sci Instrum 2022; 93:123302. [PMID: 36586889 DOI: 10.1063/5.0124833] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2022] [Accepted: 11/09/2022] [Indexed: 06/17/2023]
Abstract
For more than a decade, detonation nanodiamond (DND) powders have been actively studied as a material for efficient reflectors of very cold neutrons (VCNs) and cold neutrons. In this work, we experimentally demonstrate, for the first time, the possibility of enhanced directional extraction of a VCN beam using a reflector made of fluorinated DND powder. With respect to the theoretical flux calculated from an isotropic source at the bottom of the reflector cavity, the gain in the VCN flux density along the beam axis is ∼10 for the neutron velocities of ∼57 and ∼75 m/s. The use of such reflectors for enhanced directional extraction of VCN from neutron sources will make it possible to noticeably increase the neutron fluxes delivered to experiments and expand the scope of VCN applications.
Collapse
Affiliation(s)
- S M Chernyavsky
- National Research Center "Kurchatov Institute," 123182 Moscow, Russia
| | - M Dubois
- Université Clermont Auvergne, Clermont Auvergne INP, Institut de Chimie de Clermont-Ferrand (ICCF UMR 6296), CNRS, 63178 Auvergne, France
| | - E Korobkina
- NC State University, Raleigh, North Carolina 27695-710, USA
| | - E V Lychagin
- Joint Institute for Nuclear Research, 141980 Dubna, Russia
| | - A Yu Muzychka
- Joint Institute for Nuclear Research, 141980 Dubna, Russia
| | - G V Nekhaev
- Joint Institute for Nuclear Research, 141980 Dubna, Russia
| | | | - A Yu Nezvanov
- Joint Institute for Nuclear Research, 141980 Dubna, Russia
| | - A V Strelkov
- Joint Institute for Nuclear Research, 141980 Dubna, Russia
| | - K N Zhernenkov
- Joint Institute for Nuclear Research, 141980 Dubna, Russia
| |
Collapse
|
2
|
Nesvizhevsky VV, Voronin AY, Lambrecht A, Reynaud S, Lychagin EV, Muzychka AY, Nekhaev GV, Strelkov AV. The method of UCN "small heating" measurement in the big gravitational spectrometer (BGS) and studies of this effect on Fomblin oil Y-HVAC 18/8. Rev Sci Instrum 2018; 89:023501. [PMID: 29495873 DOI: 10.1063/1.5010974] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The Big Gravitational Spectrometer (BGS) takes advantage of the strong influence of the Earth's gravity on the motion of ultracold neutrons (UCNs) that makes it possible to shape and measure UCN spectra. We optimized the BGS to investigate the "small heating" of UCNs, that is, the inelastic reflection of UCNs from a surface accompanied by an energy change comparable with the initial UCN energy. UCNs whose energy increases are referred to as "Vaporized UCNs" (VUCNs). The BGS provides the narrowest UCN spectra of a few cm and the broadest "visible" VUCN energy range of up to ∼150 cm (UCN energy is given in units of its maximum height in the Earth's gravitational field, where 1.00 cm ≈ 1.02 neV). The dead-zone between the UCN and VUCN spectra is the narrowest ever achieved (a few cm). We performed measurements with and without samples without breaking vacuum. BGS provides the broadest range of temperatures (77-600 K) and the highest sensitivity to the small heating effect, up to ∼10-8 per bounce, i.e., two orders of magnitude higher than the sensitivity of alternative methods. We describe the method to measure the probability of UCN "small heating" using the BGS and illustrate it with a study of samples of the hydrogen-free oil Fomblin Y-HVAC 18/8. The data obtained are well reproducible, do not depend on sample thickness, and do not evolve over time. The measured model-independent probability P+ of UCN small heating from an energy "mono-line" 30.2 ± 2.5 cm to the energy range 35-140 cm is in the range 1.05±0.02stat×10-5-1.31±0.24stat×10-5 at a temperature of 24 °C. The associated systematic uncertainty would disappear if a VUCN spectrum shape were known, for instance, from a particular model of small heating. This experiment provides the most precise and reliable value of small heating probability on Fomblin measured so far. These results are of importance for studies of UCN small heating as well as for analyzing and designing neutron lifetime experiments.
Collapse
Affiliation(s)
| | | | - A Lambrecht
- Laboratoire Kastler Brossel, UPMC-Sorbonne Université, CNRS, ENS-PSL Research University, Collège de France, Campus Jussieu, 75252 Paris, France
| | - S Reynaud
- Laboratoire Kastler Brossel, UPMC-Sorbonne Université, CNRS, ENS-PSL Research University, Collège de France, Campus Jussieu, 75252 Paris, France
| | - E V Lychagin
- Joint Institute for Nuclear Research, 141980 Dubna, Russia
| | - A Yu Muzychka
- Joint Institute for Nuclear Research, 141980 Dubna, Russia
| | - G V Nekhaev
- Joint Institute for Nuclear Research, 141980 Dubna, Russia
| | - A V Strelkov
- Joint Institute for Nuclear Research, 141980 Dubna, Russia
| |
Collapse
|
3
|
Krylov AR, Lychagin EV, Muzychka AY, Nesvizhevsky VV, Nekhaev GV, Strelkov AV, Ivanov AS. Study of bound hydrogen in powders of diamond nanoparticles. CRYSTALLOGR REP+ 2011. [DOI: 10.1134/s1063774511070169] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
4
|
Mitchell GE, Furman WI, Lychagin EV, Muzichka AY, Nekhaev GV, Strelkov AV, Sharapov EI, Shvetsov VN, Chernuhin YI, Levakov BG, Litvin VI, Lyzhin AE, Magda EP, Crawford BE, Stephenson SL, Howell CR, Tornow W. Direct nn-Scattering Measurement With the Pulsed Reactor YAGUAR. J Res Natl Inst Stand Technol 2005; 110:225-30. [PMID: 27308126 PMCID: PMC4849601 DOI: 10.6028/jres.110.029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Accepted: 08/11/2004] [Indexed: 06/06/2023]
Abstract
Although crucial for resolving the issue of charge symmetry in the nuclear force, direct measurement of nn-scattering by colliding free neutrons has never been performed. At present the Russian pulsed reactor YAGUAR is the best neutron source for performing such a measurement. It has a through channel where the neutron moderator is installed. The neutrons are counted by a neutron detector located 12 m from the reactor. In preliminary experiments an instantaneous value of 1.1 × 10(18)/cm(2)s was obtained for the thermal neutron flux density. The experiment will be performed by the DIANNA Collaboration as International Science & Technology Center (ISTC) project No. 2286.
Collapse
Affiliation(s)
- G E Mitchell
- North Carolina State University, Raleigh NC, USA 27695-8202
| | - W I Furman
- Joint Institute for Nuclear Research, 141980 Dubna, Russia
| | - E V Lychagin
- Joint Institute for Nuclear Research, 141980 Dubna, Russia
| | - A Yu Muzichka
- Joint Institute for Nuclear Research, 141980 Dubna, Russia
| | - G V Nekhaev
- Joint Institute for Nuclear Research, 141980 Dubna, Russia
| | - A V Strelkov
- Joint Institute for Nuclear Research, 141980 Dubna, Russia
| | - E I Sharapov
- Joint Institute for Nuclear Research, 141980 Dubna, Russia
| | - V N Shvetsov
- Joint Institute for Nuclear Research, 141980 Dubna, Russia
| | - Yu I Chernuhin
- Russian Federal Nuclear Center-All-Russian Research Institute of Technical Physics, P.O. Box 245, 456770 Snezhinsk, Russia
| | - B G Levakov
- Russian Federal Nuclear Center-All-Russian Research Institute of Technical Physics, P.O. Box 245, 456770 Snezhinsk, Russia
| | - V I Litvin
- Russian Federal Nuclear Center-All-Russian Research Institute of Technical Physics, P.O. Box 245, 456770 Snezhinsk, Russia
| | - A E Lyzhin
- Russian Federal Nuclear Center-All-Russian Research Institute of Technical Physics, P.O. Box 245, 456770 Snezhinsk, Russia
| | - E P Magda
- Russian Federal Nuclear Center-All-Russian Research Institute of Technical Physics, P.O. Box 245, 456770 Snezhinsk, Russia
| | - B E Crawford
- Gettysburg College, Box 405, Gettysburg PA, USA 17325
| | | | - C R Howell
- Duke University and Triangle Universities Nuclear Laboratory, Durham NC, USA 27708-0308
| | - W Tornow
- Duke University and Triangle Universities Nuclear Laboratory, Durham NC, USA 27708-0308
| |
Collapse
|