ENTRY 23102 20110926 22282310200000001 SUBENT 23102001 20110926 22282310200100001 BIB 14 73 2310200100002 REFERENCE (J,NIM/A,608,144,2009) 2310200100003 #doi:10.1016/j.nima.2009.06.047 2310200100004 AUTHOR (F.Atchison, B.Blau, A.Bollhalder, M.Daum,P.Fierlinger,2310200100005 P.Geltenbort, G.Hampel, M.Kasprzak, K.Kirch, S.Koechli,2310200100006 B.Kuczewski, H.Leber, M.Locher, M.Meier, S.Ochse, 2310200100007 A.Pichlmaier,C.Plonka,R.Reiser,J.Ulrich,X.Wang,N.Wiehl,2310200100008 O.Zimmer, G.Zsigmond) 2310200100009 TITLE Transmission of very slow neutrons through material 2310200100010 foils and its influence on the design of ultracold 2310200100011 neutron sources. 2310200100012 INSTITUTE (2SWTPSI) F.Atchison,B.Blau,A.Bollhalder,M.Daum, 2310200100013 P.Fierlinger,M.Kasprzak,K.Kirch,S.Koechli,H.Leber, 2310200100014 M.Locher,M.Meier,A.Pichlmaier,R.Reiser,J.Ulrich, 2310200100015 X.Wang,G.Zsigmond. 2310200100016 (2GERMUN) M.Daum,P.Fierlinger,O.Zimmer. 2310200100017 (1USAVIR) M.Daum. 2310200100018 (2SWTZUR) Physik-Institut,Universitet Zuerich. 2310200100019 P.Fierlinger, O.Zimmer. 2310200100020 (2FR ILL) P.Geltenbort, C.Plonka, O.Zimmer. 2310200100021 (2GERMPM) Institute fuer Kernchemie, 2310200100022 Johannes-Gutenberg-Universitaet, Mainz. 2310200100023 G.Hampel,S.Ochse,C.Plonka,N.Wiehl. 2310200100024 (2AUSAUS) SMI- Stefan-Meier-Institut, Vienna,Austria. 2310200100025 M.Kasprzak. 2310200100026 Institut fuer Analitische Chemie und Radiochemie, 2310200100027 Graz University of Technology,Graz,Austria. 2310200100028 B.Kuczewski. 2310200100029 FACILITY 1(CYCLO,2SWTPSI) PSI multi-user accelerator facility, 2310200100030 590 MeV PSI ring cyclotron, power > 1.2MW. 2310200100031 2(CHOPS,2FR ILL) Very slow neutrons from turbine at ILL 2310200100032 pass through a chopper operating at duty cycle of 5.5% 2310200100033 and frequency of 0.81 Hz. 2310200100034 Experiment was designed and built at PSI. 2310200100035 The data acquisition took place at ILL. 2310200100036 INC-SOURCE1(SPALL)Spallation target made of lead-filled Zircaloy 2310200100037 tubes. Proton beam is pulsed with the duty cycle 1%, 2310200100038 for 8 sec every 800 sec. Spallation neutron are 2310200100039 thermalyzed in 3.5 m**3 heavy water (purity 99.75%). 2310200100040 In the center of heavy water volume , the cold UCN 2310200100041 converter at 5 K temperature is installed, consisted of2310200100042 a vessel filled with solid deuterium(purity 99.95%). 2310200100043 INC-SPECT 1 Thermalyzed spallation neutrons can be downscattered 2310200100044 into ultracold and very cold neutron range 2310200100045 (E-kin <500 neV) by phonon excitation. Neutrons leave 2310200100046 the cold converter,pass through the thin material of 2310200100047 the top lid, then slowed down by gravity from 5 - 9 m/s2310200100048 to 0 - 7 m/s, and become storable in the about 2 m**3 2310200100049 UCN storage volume of 2.5 m high. 2310200100050 2 Very slow neutrons of 3-20 m/sec. 2310200100051 METHOD 2(TRN,TOF) Transmission of very slow neutrons (3-20 m/s)2310200100052 was measured by time-of-flight method. 2310200100053 Flight path 2.270 m. TOF spectra were measured with and2310200100054 without sample.TOF system was calibrated by recording 2310200100055 TOF spectra of foil at two different flight paths. 2310200100056 SAMPLE Samples of different material and thickness(0.01-1 mm).2310200100057 Sample holder at 2.220 m distance from the chopper. 2310200100058 Surface roughness of the samples was not quantified. 2310200100059 DETECTOR Neutron detector was installed closely behind sample, 2310200100060 about 50 mm distance. 2310200100061 ANALYSIS Experimental values for the total cross-sections were 2310200100062 extracted from fits of transmission data with 2310200100063 exponentials. 2310200100064 ADD-RES Spherically shaped samples (Zircaloy and AlMg3) were 2310200100065 used to investigate UCN transmission through the 2310200100066 dome-like structure. Transmission probability decreases2310200100067 with increasing dome height. 2310200100068 ERR-ANALYS (DATA-ERR) Total uncertainty, including statistical 2310200100069 uncertainty, uncertainty from calibration, uncertainty 2310200100070 of flight path. 2310200100071 Defined as 1.009*(statistical uncertainty). 2310200100072 HISTORY (20090909C) M.M. 2310200100073 (20110926U) M.M. Free text "(E-kin <500 neV)" was 2310200100074 shifted. 2310200100075 ENDBIB 73 0 2310200100076 NOCOMMON 0 0 2310200100077 ENDSUBENT 76 0 2310200199999 SUBENT 23102002 20081222 22172310200200001 BIB 6 16 2310200200002 REACTION (13-AL-27(N,TOT),,SIG) 2310200200003 Measured total cross section for neutrons velocity of 2310200200004 6.2 m/s . 2310200200005 SAMPLE "Pure" Al. Weight in % : Al - 98.5, B - 3.E-3. 2310200200006 ASSUMED (ASSUM1,13-AL-27(N,ABS),,SIG) At thermal energy. 2310200200007 (ASSUM2,5-B-0(N,ABS),,SIG) At thermal energy. 2310200200008 ANALYSIS Based on the chemical composition of the samples, 2310200200009 measured after the transmission experiment only, the 2310200200010 absorption cross-sections of the samples were 2310200200011 calculated . The measured neutron loss in Al in this 2310200200012 experiment, on the basis of a 1/v dependence, is a 2310200200013 factor 2.2 higher than expected from the absorption 2310200200014 cross-section alone. 2310200200015 MISC-COL (MISC) incident neutron velocity, m/sec. 2310200200016 EN-DUMMY was calculated by compiler. 2310200200017 STATUS (TABLE) Table 3 of NIM/A,608,144,2009. 2310200200018 ENDBIB 16 0 2310200200019 COMMON 2 3 2310200200020 ASSUM1 ASSUM2 2310200200021 B B 2310200200022 0.23 767. 2310200200023 ENDCOMMON 3 0 2310200200024 DATA 4 1 2310200200025 EN-DUMMY DATA DATA-ERR MISC 2310200200026 NANO-EV B B SEE TEXT 2310200200027 200. 229. 3. 6.2 2310200200028 ENDDATA 3 0 2310200200029 ENDSUBENT 28 0 2310200299999 SUBENT 23102003 20081222 22172310200300001 BIB 6 18 2310200300002 REACTION (40-ZR-0(N,TOT),,SIG) 2310200300003 Measured total cross section for neutrons velocity of 2310200300004 5.8 m/s . 2310200300005 SAMPLE "Pure" Zr. Weight in % : Zr - 99.65, Hf - 1.E-2, 2310200300006 B - 3.E-3. 2310200300007 ASSUMED (ASSUM1,40-ZR-0(N,ABS),,SIG) At thermal energy. 2310200300008 (ASSUM2,5-B-0(N,ABS),,SIG) At thermal energy. 2310200300009 (ASSUM3,72-HF-0(N,ABS),,SIG) At thermal energy. 2310200300010 ANALYSIS Based on the chemical composition of the samples, 2310200300011 measured after the transmission experiment only, the 2310200300012 absorption cross-sections of the samples were 2310200300013 calculated . The measured neutron loss in Al in this 2310200300014 experiment, on the basis of a 1/v dependence, is a 2310200300015 factor 2.4 higher than expected from the absorption 2310200300016 cross-section alone. 2310200300017 MISC-COL (MISC) incident neutron velocity, m/sec. 2310200300018 EN-DUMMY was calculated by compiler. 2310200300019 STATUS (TABLE) Table 3 of NIM/A,608,144,2009. 2310200300020 ENDBIB 18 0 2310200300021 COMMON 3 3 2310200300022 ASSUM1 ASSUM2 ASSUM3 2310200300023 B B B 2310200300024 0.185 767. 106. 2310200300025 ENDCOMMON 3 0 2310200300026 DATA 4 1 2310200300027 EN-DUMMY DATA DATA-ERR MISC 2310200300028 NANO-EV B B SEE TEXT 2310200300029 175. 378. 5. 5.8 2310200300030 ENDDATA 3 0 2310200300031 ENDSUBENT 30 0 2310200399999 SUBENT 23102004 20081222 22172310200400001 BIB 6 16 2310200400002 REACTION (40-ZR-ALY(N,TOT),,SIG) 2310200400003 Measured total cross section for neutrons velocity of 2310200400004 5.8 m/s . 2310200400005 SAMPLE Zircaloy 110. Weight in % : Zr - 98.7, Nb - 1.1, 2310200400006 Hf - 5.E-3, B - 3.E-3. 2310200400007 ASSUMED (ASSUM1,40-ZR-0(N,ABS),,SIG) At thermal energy. 2310200400008 (ASSUM2,5-B-0(N,ABS),,SIG) At thermal energy. 2310200400009 (ASSUM3,72-HF-0(N,ABS),,SIG) At thermal energy. 2310200400010 (ASSUM4,41-NB-93(N,ABS),,SIG) At thermal energy. 2310200400011 ANALYSIS Based on the chemical composition of the samples, 2310200400012 measured after the transmission experiment only, the 2310200400013 absorption cross-sections of the samples were 2310200400014 calculated . 2310200400015 MISC-COL (MISC) incident neutron velocity, m/sec. 2310200400016 EN-DUMMY was calculated by compiler. 2310200400017 STATUS (TABLE) Table 3 of NIM/A,608,144,2009. 2310200400018 ENDBIB 16 0 2310200400019 COMMON 4 3 2310200400020 ASSUM1 ASSUM2 ASSUM3 ASSUM4 2310200400021 B B B B 2310200400022 0.185 767. 106. 1.15 2310200400023 ENDCOMMON 3 0 2310200400024 DATA 4 1 2310200400025 EN-DUMMY DATA DATA-ERR MISC 2310200400026 NANO-EV B B SEE TEXT 2310200400027 175. 313. 46. 5.8 2310200400028 ENDDATA 3 0 2310200400029 ENDSUBENT 28 0 2310200499999 SUBENT 23102005 20081222 22172310200500001 BIB 6 16 2310200500002 REACTION (40-ZR-ALY(N,TOT),,SIG) 2310200500003 Measured total cross section for neutrons velocity of 2310200500004 5.8 m/s . 2310200500005 SAMPLE Zircaloy 125. Weight in % : Zr - 97.3, Nb - 2.5, 2310200500006 Hf - 4.E-2, B - 2.E-3. 2310200500007 ASSUMED (ASSUM1,40-ZR-0(N,ABS),,SIG) At thermal energy. 2310200500008 (ASSUM2,5-B-0(N,ABS),,SIG) At thermal energy. 2310200500009 (ASSUM3,72-HF-0(N,ABS),,SIG) At thermal energy. 2310200500010 (ASSUM4,41-NB-93(N,ABS),,SIG) At thermal energy. 2310200500011 ANALYSIS Based on the chemical composition of the samples, 2310200500012 measured after the transmission experiment only, the 2310200500013 absorption cross-sections of the samples were 2310200500014 calculated . 2310200500015 MISC-COL (MISC) incident neutron velocity, m/sec. 2310200500016 EN-DUMMY was calculated by compiler. 2310200500017 STATUS (TABLE) Table 3 of NIM/A,608,144,2009. 2310200500018 ENDBIB 16 0 2310200500019 COMMON 4 3 2310200500020 ASSUM1 ASSUM2 ASSUM3 ASSUM4 2310200500021 B B B B 2310200500022 0.185 767. 106. 1.15 2310200500023 ENDCOMMON 3 0 2310200500024 DATA 4 1 2310200500025 EN-DUMMY DATA DATA-ERR MISC 2310200500026 NANO-EV B B SEE TEXT 2310200500027 175. 309. 41. 5.8 2310200500028 ENDDATA 3 0 2310200500029 ENDSUBENT 28 0 2310200599999 SUBENT 23102006 20081222 22172310200600001 BIB 6 16 2310200600002 REACTION (13-AL-CMP(N,TOT),,SIG) 2310200600003 Measured total cross section for neutrons velocity of 2310200600004 6.2 m/s . 2310200600005 SAMPLE AlMg3. Weight in % : Al - 96.7, Mg - 2.6, B - 1.E-3, 2310200600006 Mn - 0.3 . 2310200600007 ASSUMED (ASSUM1,13-AL-27(N,ABS),,SIG) At thermal energy. 2310200600008 (ASSUM2,5-B-0(N,ABS),,SIG) At thermal energy. 2310200600009 (ASSUM3,12-MG-0(N,ABS),,SIG) At thermal energy. 2310200600010 (ASSUM4,25-MN-55(N,ABS),,SIG) At thermal energy. 2310200600011 ANALYSIS Based on the chemical composition of the samples, 2310200600012 measured after the transmission experiment only, the 2310200600013 absorption cross-sections of the samples were 2310200600014 calculated . 2310200600015 MISC-COL (MISC) Incident neutron velocity, m/sec. 2310200600016 EN-DUMMY was calculated by compiler. 2310200600017 STATUS (TABLE) Table 3 of NIM/A,608,144,2009. 2310200600018 ENDBIB 16 0 2310200600019 COMMON 4 3 2310200600020 ASSUM1 ASSUM2 ASSUM3 ASSUM4 2310200600021 B B B B 2310200600022 0.23 767. 0.063 13.3 2310200600023 ENDCOMMON 3 0 2310200600024 DATA 4 1 2310200600025 EN-DUMMY DATA DATA-ERR MISC 2310200600026 NANO-EV B B SEE TEXT 2310200600027 200. 168. 9. 6.2 2310200600028 ENDDATA 3 0 2310200600029 ENDSUBENT 28 0 2310200699999 ENDENTRY 6 0 2310299999999