Scintillator ageing of the T2K near detectors from 2010 to 2021

The T2K experiment widely uses plastic scintillator as a target for neutrino interactions and an active medium for the measurement of charged particles produced in neutrino interactions at its near detector complex. Over 10 years of operation the measured light yield recorded by the scintillator based subsystems has been observed to degrade by 0.9–2.2% per year. Extrapolation of the degradation rate through to 2040 indicates the recorded light yield should remain above the lower threshold used by the current reconstruction algorithms for all subsystems. This will allow the near detectors to continue contributing to important physics measurements during the T2K-II and Hyper-Kamiokande eras. Additionally, work to disentangle the degradation of the plastic scintillator and wavelength shifting fibres shows that the reduction in light yield can be attributed to the ageing of the plastic scintillator. The long component of the attenuation length of the wavelength shifting fibres was observed to degrade by 1.3–5.4% per year, while the short component of the attenuation length did not show any conclusive degradation

Gd3+ Spin-lattice Relaxation Via Multi-band Conduction Electrons In Y1-xgdxin3: An Electron Spin Resonance Study

Interest in the electronic structure of the intermetallic compound YIn 3 has been renewed with the recent discovery of superconductivity at T ∼ 1 K, which may be filamentary in nature. In this work we perform electron spin resonance (ESR) experiments on Gd3+ doped YIn 3 (Y1-xGdxIn3; 0.001 x 0.08), showing that the spin-lattice relaxation of the Gd3+ ions, due to the exchange interaction between the Gd3+ localized magnetic moment and the conduction electrons (ce), is processed via the presence of s-, p- and d-type ce at the YIn3 Fermi level. These findings are revealed by the Gd 3+ concentration dependence of the Korringa-like relaxation rate and g-shift (Δg = g - 1.993), that display bottleneck relaxation behavior for the s-electrons and unbottleneck behavior for the p- and d-electrons. The Korringa-like relaxation rates vary from 22(2) Oe/K for x 0.001 to 8(2) Oe/K for x = 0.08 and the g-shift values change, respectively, from a positive Δg = +0.047(10) to a negative Δg = -0.008(4). Analysis in terms of a three-band ce model allows the extraction of the corresponding exchange interaction parameters Jfs, Jfp and Jfd. © 2014 IOP Publishing Ltd.2617Havinga, E.E., Damsma, H., Van Maaren, M.H., (1970) J. Phys. Chem. Solids, 31, p. 2653. , 10.1016/0022-3697(70)90261-1 0022-3697Aoki, D., Flouquet, J., (2012) J. Phys. Soc. Japan, 81, p. 011003. , 10.1143/JPSJ.81.011003 0031-9015Flouquet, J., Halperin, W.P., (2006) Progress in Low Temperature Physics, p. 139. , (Amsterdam: Elsevier)Walker, I.R., Grosche, F.M., Freye, D.M., Lonzarich, G.G., (1997) Physica, 282 (7), p. 303. , 10.1016/S0921-4534(97)00267-0 0921-4534 CPluzhnikov, V.B., Czopnik, A., Svechkarev, I.V., (1995) Physica, 212, p. 375. , 10.1016/0921-4526(95)00382-J 0921-4526 BMucha, J., Thermal conductivity of REIn3 compounds (2006) Journal of Physics Condensed Matter, 18 (4), pp. 1427-1439. , DOI 10.1088/0953-8984/18/4/026, PII S0953898406092538Hale, L., Gschneidner Jr., K.A., Pecharsky, V.K., Mudryk, Y., (2009) J. Alloys Compounds, 472, p. 24. , 10.1016/j.jallcom.2008.04.097 0925-8388Johnson, S.D., Younga, J.R., Zieve, R.J., Cooley, J.C., (2012) Solid State Commun., 152, pp. 513-515. , 10.1016/j.ssc.2011.12.040 0038-1098Billington, D., Llewellyn-Jones, T.M., Maroso, G., Dugdale, S.B., (2013) Supercond. Sci. Technol., 26 (8), p. 085007. , 10.1088/0953-2048/26/8/085007 0953-2048 085007Ram, S., Kanchana, V., Svane, A., Dugdale, S.B., Christensen, N.E., (2013) J. Phys.: Condens. Matter, 25 (15), p. 155501. , 10.1088/0953-8984/25/15/155501 0953-8984 155501Taylor, R.H., (1975) Adv. Phys., 24, p. 681. , 10.1080/00018737500101501 0001-8732Barnes, S.E., (1981) Adv. Phys., 30, pp. 801-938. , 10.1080/00018738100101447 0001-8732Hasegawa, H., (1959) Prog. Theor. Phys., 21, p. 483. , 10.1143/PTP.21.483 0033-068XKorringa, J., (1950) Physica, 16, p. 601. , 10.1016/0031-8914(50)90105-4 0031-8914Davidov, D., Chelkowski, A., Rettori, C., Orbach, R., Maple, M.B., (1973) Phys. Rev., 7, p. 1029. , 10.1103/PhysRevB.7.1029 0556-2805 BRettori, C., Kim, H.M., Chock, E.P., Davidov, D., (1974) Phys. Rev., 10, p. 1826. , 10.1103/PhysRevB.10.1826 0556-2805 BRettori, C., Davidov, D., Orbach, R., Chock, E.P., Ricks, B., (1973) Phys. Rev., 7, p. 1. , 10.1103/PhysRevB.7.1 0556-2805 BCanfield, P.C., Fisk, Z., (1992) Phil. Mag., 65, p. 1117. , 10.1080/13642819208215073 0141-8610Ribeiro, R.A., Avila, M.A., (2012) Phil. Mag., 92, p. 2492. , 10.1080/14786435.2012.682179Amara, A., Morin, P., Rouchy, J., (1994) J. Magn. Magn. Mater., 130, pp. 115-126. , 10.1016/0304-8853(94)90664-5 0304-8853Abragam, A., Bleaney, B., (1970) Electron Paramagnetic resonance (EPR) of Transition IonsFeher, G., Kip, A.F., (1955) Phys. Rev., 98, p. 337. , 10.1103/PhysRev.98.337Dyson, F.J., (1955) Phys. Rev., 98, p. 349. , 10.1103/PhysRev.98.349Kaplan, J.I., (1959) Phys. Rev., 115, p. 575. , 10.1103/PhysRev.115.575Pake, G.E., Purcell, E.M., (1948) Phys. Rev., 74, p. 1184. , 10.1103/PhysRev.74.1184Poole Jr., C.P., (1969) Electron Spin Resonance: A Comprehensive Treatise on Experimental Techniques, pp. 705-717Urbano, R.R., Bittar, E.M., Pires, M.A., Mendonca-Ferreira, L., Bufaical, L., Rettori, C., Pagliuso, P.G., Oseroff, S.B., (2007) Phys. Rev., 75, p. 045107. , 10.1103/PhysRevB.75.045107 BDavidov, D., Maki, K., Orbach, R., Rettori, C., Chock, E.P., (1973) Solid State Commun., 12, p. 621. , 10.1016/0038-1098(73)90299-8 0038-1098Shaw, R.W., Warren Jr., W.W., (1971) Phys. Rev., 3, p. 1562. , 10.1103/PhysRevB.3.1562 0556-2805 BBittar, E.M., Adriano, C., Giles, C., Rettori, C., Fisk, Z., Pagliuso, P.G., (2012) Phys. Rev., 86, p. 125108. , 10.1103/PhysRevB.86.125108 BDewhurst, K., Sharma, S., Nordström, L., Gross, H., (2013) EUR FP-LAPW Code, , http://elk.sourceforge.netPerdew, J.P., Ruzsinszky, A., Csonka, G.I., Vydrov, O.A., Scuseria, G.E., Constantin, L.A., Zhou, X., Burke, K., Restoring the density-gradient expansion for exchange in solids and surfaces (2008) Physical Review Letters, 100 (13), p. 136406. , http://oai.aps.org/oai?verb=GetRecord&Identifier=oai:aps.org: PhysRevLett.100.136406&metadataPrefix=oai_apsmeta_2, DOI 10.1103/PhysRevLett.100.13640