32:
1151:(perfluoropolyether vacuum oil)). Using traps with different surface to volume ratios allowed them to separate storage decay time and neutron lifetime from each other. There is another result, with even smaller uncertainty, but which is not included in the World average. It was obtained by Serebrov et al., who found
445:
who realized first that the coherent scattering of slow neutrons would result in an effective interaction potential for neutrons traveling through matter, which would be positive for most materials. The consequence of such a potential would be the total reflection of neutrons slow enough and incident
2117:
Pattie, R. W.; Anaya, J.; Back, H. O.; Boissevain, J. G.; Bowles, T. J.; Broussard, L. J.; Carr, R.; Clark, D. J.; Currie, S.; Du, S.; Filippone, B. W.; Geltenbort, P.; García, A.; Hawari, A.; Hickerson, K. P.; Hill, R.; Hino, M.; Hoedl, S. A.; Hogan, G. E.; Holley, A. T.; Ito, T. M.; Kawai, T.;
1013:
The production, transportation and storage of UCN is currently motivated by their usefulness as a tool to determine properties of the neutron and to study fundamental physical interactions. Storage experiments have improved the accuracy or the upper limit of some neutron related physical values.
485:
After protons are accelerated to around 600 MeV they impinge on a lead target and produce neutrons via spallation. These neutrons are thermalized in e.g. heavy water and then moderated e.g. in liquid or solid deuterium to be cold. The final production of UCN occurs via downscattering in solid
2186:
Liu, J.; Mendenhall, M. P.; Holley, A. T.; Back, H. O.; Bowles, T. J.; Broussard, L. J.; Carr, R.; Clayton, S.; Currie, S.; Filippone, B. W.; García, A.; Geltenbort, P.; Hickerson, K. P.; Hoagland, J.; Hogan, G. E.; Hona, B.; Ito, T. M.; Liu, C.-Y.; Makela, M.; Mammei, R. R.; Martin, J. W.;
1249:
is a measure for the distribution of positive and negative charge inside the neutron. No neutron electric dipole moment has been found as of
October 2019). The lowest value for the upper limit of the neutron electric dipole moment was measured with stored UCN (see main article).
1310:
The first reported measurement of the beta-asymmetry using UCN is from a Los Alamos group in 2009. The LANSCE group published precision measurements with polarized UCN the next year. Further measurements by these groups and others have led to the current world average:
1994:
Jenke, T.; Cronenberg, G.; Burgdörfer, J.; Chizhova, L. A.; Geltenbort, P.; Ivanov, A. N.; Lauer, T.; Lins, T.; Rotter, S.; Saul, H.; Schmidt, U.; Abele, H. (16 April 2014). "Gravity
Resonance Spectroscopy Constrains Dark Energy and Dark Matter Scenarios".
1145:
992:
1229:
1374:
481:
A neutron turbine in which neutrons at 50 m/s are directed against the blades of a turbine wheel with receding tangential velocity 25 m/s, from which neutrons emerge after multiple reflections with a speed of about
2187:
Melconian, D.; Morris, C. L.; Pattie, R. W.; Pérez Galván, A.; Pitt, M. L.; Plaster, B.; Ramsey, J. C.; Rios, R.; et al. (Jul 2010). "Determination of the Axial-Vector Weak
Coupling Constant with Ultracold Neutrons".
477:
Neutrons transported from the reactor though a vertical evacuated guide about 11 meters long are slowed down by gravity, so only those that happened to have ultracold energies can reach the detector at the top of the
657:
Any material with a positive neutron optical potential can reflect UCN. The table on the right gives an (incomplete) list of UCN reflecting materials including the height of the neutron optical potential
1875:
Arzumanov, S; Bondarenko, L; Chernyavsky, S; Drexel, W; Fomin, A; et al. (2000). "Neutron life time value measured by storing ultracold neutrons with detection of inelastically scattered neutrons".
808:
702:
Non-magnetic materials such as DLC are usually preferred for the use with polarized neutrons. Magnetic centers in e.g. Ni can lead to de-polarization of such neutrons upon reflection. If a material is
1055:
1354:
881:
1060:
892:
838:
1643:
1154:
392:
of a material. Neutrons are reflected from a surface if the velocity component normal to the reflecting surface is less than or equal to the critical velocity.
1266:
do not move smoothly but jump from one height to another, as predicted by quantum theory. The finding could be used to probe fundamental physics such as the
415:
with a temperature of 3.5 mK. Moreover, materials with a high optical potential (~ 1 μeV) are used for the design of cold neutrons optical components.
474:
The use of a horizontal evacuated tube from the reactor, curved so all but UCN would be absorbed by the walls of the tube before reaching the detector.
1604:
A. Steyerl; H. Nagel; F.-X. Schreiber; K.-A. Steinhauser; R. Gähler; W. Gläser; P. Ageron; J. M. Astruc; W. Drexel; G. Gervais & W. Mampe (1986).
100:
337:
269:
422:
is significant. Thus, the trajectories are parabolic. Kinetic energy of an UCN is transformed into potential (height) energy with ~102 neV/m.
2056:
Kamiya, Y.; Itagaki, K.; Tani, M.; Kim, G. N.; Komamiya, S. (22 April 2015). "Constraints on New
Gravitylike Forces in the Nanometer Range".
1148:
1005:). It is caused by absorption and thermal upscattering. The loss coefficient η is energy-independent and typically of the order of 10 to 10.
377:
of the neutron with atomic nuclei. It can be quantum-mechanically described by an effective potential which is commonly referred to as the
2249:
1373:
Hadden, Elhoucine; Iso, Yuko; Kume, Atsushi; Umemoto, Koichi; Jenke, Tobias; Fally, Martin; Klepp, Jürgen; Tomita, Yasuo (2022-05-24).
295:
361:
which can be stored in traps made from certain materials. The storage is based on the reflection of UCN by such materials under any
159:
1258:
Physicists have observed quantized states of matter under the influence of gravity for the first time. Valery
Nesvizhevsky of the
712:
259:
1569:
Steyerl, A. (1969). "Measurements of total cross sections for very slow neutrons with velocities from 100 m/sec to 5 m/sec".
455:
291:
2118:
Kirch, K.; Kitagaki, S.; Lamoreaux, S. K.; Liu, C.-Y.; Liu, J.; Makela, M.; Mammei, R. R.; et al. (5 January 2009).
330:
1669:"Measured velocity spectra and neutron densities of the PF2 ultracold-neutron beam ports at the Institut Laue–Langevin"
1402:
245:
179:
122:
1375:"Nanodiamond-based nanoparticle-polymer composite gratings with extremely large neutron refractive index modulation"
1025:
1246:
1240:
459:
451:
323:
117:
95:
1317:
301:
470:
There are various methods for the production of UCN. Such facilities have been built and are in operation:
287:
112:
1270:, which states that different masses accelerate at the same rate in a gravitational field (V Nesvizhevsky
408:
400:
362:
155:
847:
311:
283:
1921:"Measurement of the neutron lifetime using a gravitational trap and a low-temperature Fomblin coating"
450:
and Fermi and Leona
Marshall. The storage of neutrons with very low kinetic energies was predicted by
2253:
1668:
253:
241:
2274:
1140:{\displaystyle \tau _{n}=885.4\pm 0.9_{\mathrm {stat} }\pm 0.4_{\mathrm {syst} }\,{\mathrm {s} }\,}
275:
987:{\displaystyle \mu (E,\theta )=2\eta {\sqrt {\frac {E\cos ^{2}\theta }{V_{F}-E\cos ^{2}\theta }}}}
494:
841:
672:). The height of the neutron optical potential is isotope-specific. The highest known value of V
411:
of 52 nm. As their density is usually very small, UCN can also be described as a very thin
1377:. In McLeod, Robert R; Tomita, Yasuo; Sheridan, John T; Pascual Villalobos, Inmaculada (eds.).
1259:
169:
127:
1919:
Serebrov, A.; Varlamov, V.; Kharitonov, A.; Fomin, A.; Pokotilovski, Yu.; et al. (2005).
816:
2261:
1267:
105:
64:
680: = 8.14 m/s). It defines the upper limit of the kinetic energy range of UCN.
2206:
2144:
2075:
2014:
1942:
1885:
1831:
1690:
1617:
1578:
1483:
1448:
1382:
446:
on a surface at a glancing angle. This effect was experimentally demonstrated by Fermi and
174:
2119:
1224:{\displaystyle 878.5~\pm 0.7_{\mathrm {stat} }\pm 0.4_{\mathrm {syst} }\,{\mathrm {s} }\,}
403:, especially for normal incidence. The kinetic energy of 300 neV corresponds to a maximum
8:
1305:
1263:
696:
90:
46:
2210:
2148:
2079:
2018:
1946:
1889:
1835:
1694:
1621:
1582:
1487:
1452:
1386:
2230:
2196:
2168:
2134:
2099:
2065:
2038:
2004:
1971:
1932:
1920:
1821:
1761:
1733:
1706:
1680:
1408:
374:
231:
150:
81:
72:
68:
1897:
1605:
2222:
2160:
2091:
2030:
1976:
1958:
1901:
1849:
1844:
1809:
1765:
1753:
1710:
1629:
1590:
1509:
1412:
1398:
447:
222:
213:
207:
132:
59:
55:
2234:
2172:
2103:
2042:
2294:
2218:
2214:
2156:
2152:
2087:
2083:
2026:
2022:
1966:
1954:
1950:
1893:
1839:
1748:
1743:
1698:
1625:
1586:
1504:
1499:
1491:
1456:
1390:
1274:
2001 Nature 415 297). UCN spectroscopy has been used to limit scenarios including
1057:, to which the experiment of Arzumanov et al. contributes strongest. Ref. measured
490:
487:
199:
1603:
706:, the neutron optical potential is different for the two polarizations, caused by
399:
of incident neutrons must not be higher than this value to be reflected under any
305:
1474:
Fermi, E.; Marshall, L. (1947-05-15). "Interference
Phenomena of Slow Neutrons".
1279:
688:
426:
1702:
1253:
430:
396:
195:
2288:
1962:
1905:
1853:
1757:
1513:
1295:
703:
1725:
2226:
2164:
2095:
2034:
1980:
1495:
1300:
442:
433:, interacts with magnetic fields. The total energy changes with ~60 neV/T.
379:
358:
51:
1460:
31:
1826:
1666:
1439:
Anonymous (1946). "Minutes of the
Meeting at Chicago, June 20-22, 1946".
1275:
419:
395:
As the neutron optical potential of most materials is below 300 neV, the
217:
1937:
2247:
1394:
203:
2120:"First Measurement of the Neutron β Asymmetry with Ultracold Neutrons"
1306:
Measurement of the A-coefficient of the neutron beta decay correlation
1231:. Thus, the two most precisely measured values deviate by 5.6 σ.
684:
637:
528:
412:
1874:
1726:"UCN, the ultracold neutron source -- neutrons for particle physics"
1289:
1234:
2070:
1738:
1685:
590:
404:
2201:
2139:
2009:
1993:
575:
23:
883:
the magnetic field created on the surface by the magnetization.
1918:
1667:
Stefan Döge; Jürgen
Hingerl & Christoph Morkel (Feb 2020).
1529:
Soviet
Physics Journal of Experimental& Theoretical Physics
886:
Each material has a specific loss probability per reflection,
692:
621:
559:
279:
265:
1808:
al, W-M Yao; et al. (Particle Data Group) (2006-07-01).
1283:
1254:
Observation of the gravitational interactions of the neutron
803:{\displaystyle V_{F}(pol.)=V_{F}(unpol.)\pm \mu _{N}\cdot B}
418:
Due to the small kinetic energy of an UCN, the influence of
249:
605:
2116:
997:
which depends on the kinetic energy of the incident UCN (
683:
The most widely used materials for UCN wall coatings are
544:
1301:
Measurement of the neutron-anti-neutron oscillation time
1022:
Today's world average value for the neutron lifetime is
491:
was realized at the Paul Scherrer Institute, Switzerland
454:
and experimentally realized simultaneously by groups at
2185:
1017:
1859:
1527:
Zeldovich, Ya.B. (1959). "Storage of cold neutrons".
1320:
1157:
1063:
1028:
895:
850:
819:
715:
2055:
1372:
1262:
and colleagues found that cold neutrons moving in a
1147:
by storage of UCN in a material bottle covered with
1814:Journal of Physics G: Nuclear and Particle Physics
1597:
1379:Photosensitive Materials and their Applications II
1348:
1223:
1139:
1049:
986:
875:
832:
802:
1290:Search for Neutron to Mirror-Neutron Oscillations
1235:Measurement of the neutron electric dipole moment
2286:
2248:K.A. Olive et al. (Particle Data Group) (2014).
1482:(10). American Physical Society (APS): 666–677.
1858:and 2007 partial update for edition 2008 (URL:
1660:
1724:Lauss, Bernhard; Blau, Bertrand (2021-09-06).
1050:{\displaystyle 885.7\pm 0.8\,{\mathrm {s} }\,}
1790:
1788:
1606:"A new source of cold and ultracold neutrons"
1473:
331:
1870:
1868:
665:) and the corresponding critical velocity (
388:. The corresponding velocity is called the
1785:
1544:
1542:
338:
324:
2200:
2138:
2069:
2008:
1970:
1936:
1865:
1843:
1825:
1778:R. Golub, D. Richardson, S.K. Lamoreaux,
1747:
1737:
1723:
1684:
1564:
1562:
1526:
1503:
1438:
1381:. Vol. 12151. SPIE. pp. 70–76.
1220:
1212:
1136:
1128:
1046:
1038:
373:The reflection is caused by the coherent
16:Free neutrons stored in very small traps
1568:
1539:
1349:{\displaystyle A_{0}=-0.1184\pm 0.0010}
1008:
500:
2287:
1559:
695:(including Ni) and more recently also
1772:
1798:, Clarendon Press (1990), Oxford, UK
495:Los Alamos National Laboratory, USA.
164:Fundamental research with neutrons:
1801:
1018:Measurement of the neutron lifetime
13:
1807:
1215:
1206:
1203:
1200:
1197:
1182:
1179:
1176:
1173:
1131:
1122:
1119:
1116:
1113:
1098:
1095:
1092:
1089:
1041:
14:
2306:
1796:The Physics of Ultracold Neutrons
876:{\displaystyle B=\mu _{0}\cdot M}
465:
429:of the neutron, produced by its
160:Prompt gamma activation analysis
30:
2241:
2179:
2110:
2049:
1987:
1912:
1717:
2219:10.1103/PhysRevLett.105.181803
2157:10.1103/PhysRevLett.102.012301
2088:10.1103/PhysRevLett.114.161101
2027:10.1103/PhysRevLett.112.151105
1955:10.1016/j.physletb.2004.11.013
1749:10.21468/SciPostPhysProc.5.004
1636:
1520:
1467:
1432:
1425:E. Fermi, Ricerca Scientifica
1419:
1366:
1247:neutron electric dipole moment
1241:Neutron electric dipole moment
1001:) and the angle of incidence (
911:
899:
842:magnetic moment of the neutron
778:
757:
741:
726:
676:is measured for Ni: 335 neV (v
96:Small-angle neutron scattering
1:
1898:10.1016/s0370-2693(00)00579-7
1782:, Adam Hilger (1991), Bristol
1359:
407:of 7.6 m/s or a minimum
368:
1810:"Review of Particle Physics"
1630:10.1016/0375-9601(86)90587-6
1591:10.1016/0370-2693(69)90127-0
288:ISIS Neutron and Muon Source
113:Inelastic neutron scattering
7:
1884:(1–3). Elsevier BV: 15–22.
1730:SciPost Physics Proceedings
452:Yakov Borisovich Zel'dovich
128:Backscattering spectrometer
123:Time-of-flight spectrometer
10:
2311:
1845:10.1088/0954-3899/33/1/001
1703:10.1016/j.nima.2019.163112
1238:
436:
2250:"e−Asymmetry Parameter A"
386:neutron optical potential
1673:Nucl. Instrum. Methods A
1552:, Sov. Phys. JETP Lett.
833:{\displaystyle \mu _{N}}
118:Triple-axis spectrometer
2189:Physical Review Letters
2127:Physical Review Letters
2058:Physical Review Letters
1997:Physical Review Letters
1505:2027/mdp.39015074124465
1282:, and new short range
180:Neutron capture therapy
2269:Cite journal requires
1496:10.1103/physrev.71.666
1350:
1260:Institut Laue-Langevin
1225:
1141:
1051:
988:
877:
834:
804:
133:Spin-echo spectrometer
1461:10.1103/PhysRev.70.99
1351:
1268:equivalence principle
1226:
1142:
1052:
989:
878:
835:
805:
1318:
1155:
1061:
1026:
1009:Experiments with UCN
893:
848:
817:
713:
501:Reflecting materials
310:Under construction:
175:Fast neutron therapy
2211:2010PhRvL.105r1803L
2149:2009PhRvL.102a2301P
2080:2015PhRvL.114p1101K
2019:2014PhRvL.112o1105J
1947:2005PhLB..605...72S
1890:2000PhLB..483...15A
1836:2006JPhG...33....1Y
1780:Ultra-Cold Neutrons
1695:2020NIMPA.95363112D
1622:1986PhLA..116..347S
1583:1969PhLB...29...33S
1488:1947PhRv...71..666F
1453:1946PhRv...70...99.
1387:2022SPIE12151E..09H
1264:gravitational field
697:diamond-like carbon
156:Activation analysis
91:Neutron diffraction
47:Neutron temperature
1860:http://pdg.lbl.gov
1395:10.1117/12.2623661
1346:
1221:
1137:
1047:
984:
873:
830:
800:
401:angle of incidence
375:strong interaction
363:angle of incidence
351:Ultracold neutrons
232:Neutron facilities
166:Ultracold neutrons
151:Neutron tomography
143:Other applications
82:Neutron scattering
1925:Physics Letters B
1878:Physics Letters B
1794:V.K. Ignatovich,
1644:"ILL Yellow Book"
1571:Physics Letters B
1163:
982:
981:
655:
654:
448:Walter Henry Zinn
390:critical velocity
348:
347:
208:Neutron moderator
2302:
2279:
2278:
2272:
2267:
2265:
2257:
2252:. Archived from
2245:
2239:
2238:
2204:
2183:
2177:
2176:
2142:
2124:
2114:
2108:
2107:
2073:
2053:
2047:
2046:
2012:
1991:
1985:
1984:
1974:
1940:
1916:
1910:
1909:
1872:
1863:
1857:
1847:
1829:
1827:astro-ph/0601514
1805:
1799:
1792:
1783:
1776:
1770:
1769:
1751:
1741:
1721:
1715:
1714:
1688:
1664:
1658:
1657:
1655:
1654:
1640:
1634:
1633:
1601:
1595:
1594:
1566:
1557:
1546:
1537:
1536:
1524:
1518:
1517:
1507:
1471:
1465:
1464:
1436:
1430:
1423:
1417:
1416:
1370:
1355:
1353:
1352:
1347:
1330:
1329:
1280:chameleon fields
1230:
1228:
1227:
1222:
1219:
1218:
1211:
1210:
1209:
1187:
1186:
1185:
1161:
1146:
1144:
1143:
1138:
1135:
1134:
1127:
1126:
1125:
1103:
1102:
1101:
1073:
1072:
1056:
1054:
1053:
1048:
1045:
1044:
993:
991:
990:
985:
983:
980:
973:
972:
957:
956:
946:
939:
938:
925:
924:
882:
880:
879:
874:
866:
865:
839:
837:
836:
831:
829:
828:
809:
807:
806:
801:
793:
792:
756:
755:
725:
724:
644:
505:
504:
486:deuterium. Such
382:pseudo potential
340:
333:
326:
212:Neutron optics:
200:Research reactor
34:
19:
18:
2310:
2309:
2305:
2304:
2303:
2301:
2300:
2299:
2285:
2284:
2283:
2282:
2270:
2268:
2259:
2258:
2246:
2242:
2184:
2180:
2122:
2115:
2111:
2054:
2050:
1992:
1988:
1938:nucl-ex/0408009
1917:
1913:
1873:
1866:
1806:
1802:
1793:
1786:
1777:
1773:
1722:
1718:
1665:
1661:
1652:
1650:
1642:
1641:
1637:
1602:
1598:
1567:
1560:
1547:
1540:
1525:
1521:
1476:Physical Review
1472:
1468:
1441:Physical Review
1437:
1433:
1424:
1420:
1405:
1371:
1367:
1362:
1325:
1321:
1319:
1316:
1315:
1308:
1303:
1292:
1256:
1243:
1237:
1214:
1213:
1196:
1195:
1191:
1172:
1171:
1167:
1156:
1153:
1152:
1130:
1129:
1112:
1111:
1107:
1088:
1087:
1083:
1068:
1064:
1062:
1059:
1058:
1040:
1039:
1027:
1024:
1023:
1020:
1011:
968:
964:
952:
948:
947:
934:
930:
926:
923:
894:
891:
890:
861:
857:
849:
846:
845:
824:
820:
818:
815:
814:
788:
784:
751:
747:
720:
716:
714:
711:
710:
689:beryllium oxide
679:
675:
670:
663:
642:
520:
514:
503:
468:
439:
427:magnetic moment
371:
344:
196:Neutron sources
17:
12:
11:
5:
2308:
2298:
2297:
2281:
2280:
2271:|journal=
2256:on 2015-04-26.
2240:
2195:(18): 181803.
2178:
2109:
2064:(16): 161101.
2048:
2003:(15): 151105.
1986:
1931:(1–2): 72–78.
1911:
1864:
1800:
1784:
1771:
1716:
1659:
1635:
1616:(7): 347–352.
1596:
1558:
1548:V.I. Lushikov
1538:
1519:
1466:
1431:
1418:
1403:
1364:
1363:
1361:
1358:
1357:
1356:
1345:
1342:
1339:
1336:
1333:
1328:
1324:
1307:
1304:
1302:
1299:
1291:
1288:
1255:
1252:
1239:Main article:
1236:
1233:
1217:
1208:
1205:
1202:
1199:
1194:
1190:
1184:
1181:
1178:
1175:
1170:
1166:
1160:
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1118:
1115:
1110:
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1100:
1097:
1094:
1091:
1086:
1082:
1079:
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994:
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960:
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780:
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774:
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768:
765:
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754:
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746:
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734:
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728:
723:
719:
677:
673:
668:
661:
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640:
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633:
630:
627:
624:
618:
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614:
611:
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602:
601:
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587:
586:
584:
581:
578:
572:
571:
568:
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562:
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553:
550:
547:
541:
540:
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534:
531:
525:
524:
521:
518:
515:
512:
509:
502:
499:
498:
497:
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479:
475:
467:
466:UCN production
464:
438:
435:
397:kinetic energy
370:
367:
346:
345:
343:
342:
335:
328:
320:
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272:
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190:
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188:Infrastructure
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172:
170:Interferometry
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98:
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36:
35:
27:
26:
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9:
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3:
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2251:
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2236:
2232:
2228:
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2162:
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2077:
2072:
2067:
2063:
2059:
2052:
2044:
2040:
2036:
2032:
2028:
2024:
2020:
2016:
2011:
2006:
2002:
1998:
1990:
1982:
1978:
1973:
1968:
1964:
1960:
1956:
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1948:
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1934:
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1926:
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1828:
1823:
1820:(1): 1–1232.
1819:
1815:
1811:
1804:
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1767:
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1759:
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1611:
1610:Phys. Lett. A
1607:
1600:
1592:
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1563:
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1334:
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1314:
1313:
1312:
1298:
1297:
1296:Mirror Matter
1287:
1285:
1281:
1277:
1273:
1269:
1265:
1261:
1251:
1248:
1242:
1232:
1192:
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1168:
1164:
1158:
1150:
1108:
1104:
1084:
1080:
1077:
1074:
1069:
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1032:
1029:
1015:
1006:
1004:
1000:
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969:
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958:
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920:
917:
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896:
889:
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870:
867:
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851:
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794:
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785:
781:
775:
772:
769:
766:
763:
760:
752:
748:
744:
738:
735:
732:
729:
721:
717:
709:
708:
707:
705:
700:
698:
694:
690:
686:
681:
671:
664:
650:
648:3.24 m/s
647:
641:
639:
636:
635:
631:
629:5.66 m/s
628:
625:
623:
620:
619:
615:
613:6.10 m/s
612:
609:
607:
604:
603:
600:
598:5.47 m/s
597:
594:
592:
589:
588:
585:
583:7.65 m/s
582:
579:
577:
574:
573:
569:
567:6.84 m/s
566:
563:
561:
558:
557:
554:
552:6.99 m/s
551:
548:
546:
543:
542:
538:
536:6.89 m/s
535:
532:
530:
527:
526:
522:
516:
510:
507:
506:
496:
492:
489:
484:
480:
476:
473:
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461:
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453:
449:
444:
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428:
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421:
416:
414:
410:
406:
402:
398:
393:
391:
387:
383:
381:
376:
366:
364:
360:
359:free neutrons
356:
352:
341:
336:
334:
329:
327:
322:
321:
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318:
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307:
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299:
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142:
141:
134:
131:
129:
126:
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121:
119:
116:
115:
114:
111:
107:
106:Reflectometry
104:
102:
99:
97:
94:
93:
92:
89:
88:
87:
86:
83:
80:
79:
74:
70:
66:
65:Cross section
63:
61:
57:
53:
50:
48:
45:
44:
43:
42:
38:
37:
33:
29:
28:
25:
22:Science with
21:
20:
2262:cite journal
2254:the original
2243:
2192:
2188:
2181:
2130:
2126:
2112:
2061:
2057:
2051:
2000:
1996:
1989:
1928:
1924:
1914:
1881:
1877:
1817:
1813:
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1779:
1774:
1729:
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1662:
1651:. Retrieved
1647:
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1574:
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1522:
1479:
1475:
1469:
1444:
1440:
1434:
1426:
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1309:
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1257:
1244:
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1012:
1002:
998:
996:
885:
812:
701:
682:
666:
659:
656:
488:a UCN source
469:
443:Enrico Fermi
440:
424:
417:
394:
389:
385:
378:
372:
354:
350:
349:
165:
1447:(1–2): 99.
1276:dark energy
1149:Fomblin oil
493:and at the
482:5 m/s.
420:gravitation
258:Australia:
218:Supermirror
39:Foundations
2071:1504.02181
1739:2104.02457
1732:(5): 004.
1686:2001.04538
1679:: 163112.
1653:2022-06-05
1648:www.ill.eu
1360:References
704:magnetized
409:wavelength
369:Properties
300:Historic:
240:America:
204:Spallation
73:Activation
69:Absorption
2202:1007.3790
2140:0809.2941
2010:1404.4099
1963:0370-2693
1906:0370-2693
1854:0954-3899
1766:233033971
1758:2666-4003
1711:209942845
1556:(1969) 23
1514:0031-899X
1429:(1936) 13
1413:249056691
1341:±
1335:−
1189:±
1165:±
1105:±
1081:±
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959:−
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921:η
909:θ
897:μ
868:⋅
859:μ
822:μ
795:⋅
786:μ
782:±
685:beryllium
638:Aluminium
529:Beryllium
508:Material:
413:ideal gas
223:Detection
214:Reflector
60:Transport
56:Radiation
2289:Category
2235:16055409
2227:21231098
2173:13048589
2165:19257182
2104:10982682
2096:25955041
2043:38389662
2035:24785025
1981:27308146
591:Graphite
539:2.0–8.5
405:velocity
274:Europe:
250:NIST CNR
24:neutrons
2295:Neutron
2207:Bibcode
2145:Bibcode
2076:Bibcode
2015:Bibcode
1972:4852839
1943:Bibcode
1886:Bibcode
1832:Bibcode
1691:Bibcode
1618:Bibcode
1579:Bibcode
1535:: 1389.
1484:Bibcode
1449:Bibcode
1383:Bibcode
840:is the
699:(DLC).
651:2.9–10
632:2.1–16
626:168 neV
616:1.7–28
610:210 neV
595:180 neV
580:304 neV
576:Diamond
564:252 neV
549:261 neV
533:252 neV
523:η (10)
441:It was
437:History
384:or the
2233:
2225:
2171:
2163:
2102:
2094:
2041:
2033:
1979:
1969:
1961:
1904:
1852:
1764:
1756:
1709:
1550:et al.
1512:
1411:
1401:
1344:0.0010
1338:0.1184
1284:forces
1272:et al.
1162:
813:where
693:nickel
645:54 neV
622:Copper
560:Nickel
460:Munich
357:) are
280:FRM II
276:BER II
270:HANARO
266:J-PARC
264:Asia:
246:LANSCE
101:GISANS
2231:S2CID
2197:arXiv
2169:S2CID
2135:arXiv
2123:(PDF)
2100:S2CID
2066:arXiv
2039:S2CID
2005:arXiv
1933:arXiv
1822:arXiv
1762:S2CID
1734:arXiv
1707:S2CID
1681:arXiv
1409:S2CID
1159:878.5
1078:885.4
1030:885.7
478:tube.
456:Dubna
380:Fermi
2275:help
2223:PMID
2161:PMID
2092:PMID
2031:PMID
1977:PMID
1959:ISSN
1902:ISSN
1850:ISSN
1754:ISSN
1510:ISSN
1399:ISBN
1294:see
1245:The
844:and
606:Iron
570:5.1
458:and
431:spin
425:The
306:HFBR
302:IPNS
296:SINQ
292:JINR
260:OPAL
242:HFIR
52:Flux
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2153:doi
2131:102
2084:doi
2062:114
2023:doi
2001:112
1967:PMC
1951:doi
1929:605
1894:doi
1882:483
1840:doi
1744:doi
1699:doi
1677:953
1626:doi
1614:116
1587:doi
1500:hdl
1492:doi
1457:doi
1391:doi
1193:0.4
1169:0.7
1109:0.4
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1036:0.8
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545:BeO
355:UCN
312:ESS
284:ILL
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