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The excitation function for the (63)Cu(n,p)(63)Ni reaction has been measured by activation method using the 4.5 MV Dynamitron accelerator of the Fast Neutron Laboratory of Tohoku University. Copper plates and hollow spherical copper shells were irradiated by neutrons of various energy up to 14.9 MeV produced by the T(p,n), D(d,n), and T(d,n) reactions. The (63)Ni produced in the irradiated copper target was chemically separated. The beta-rays emitted from the extracted (63)Ni were measured by a liquid scintillation method. The cross sections obtained were compared with the evaluated data files of JENDL-3.3, ENDF/B-VI and FENDL/A-2.0. Consequently, it is found that FENDL/A-2.0 is consistent with our experimental data in the energy range studied in this work. The effect of proton shell appeared in the excitation function obtained is also discussed.

The upper and lower limits of the excitation function of the (63)Cu(n,p)(63)Ni reaction were experimentally determined, and the number of (63)Ni nuclei produced in copper samples exposed to atomic bomb neutrons in Hiroshima was estimated by using the experimental excitation functions and the neutron fluences given in the DS02 dosimetry system. The estimated number of (63)Ni nuclei was compared with that measured and with that calculated using the DS02 dosimetry system and the corresponding ENDF/B-VI cross section. In comparison with DS02, there is about a 60% maximum difference in (63)Ni production at the hypocenter when the experimental upper cross section values are used. The difference becomes smaller at greater distances from the hypocenter and decreases, for example, to less than 30 and 5% when using the upper and lower experimental cross sections at 1,000 m, respectively.

The liquid–liquid microbatch extraction system (LMES) was developed for rapid separation of short-lived metal ions. The equipment is composed of three simple extraction cells for phase mixing, phase separation, and collection of a solvent. Metal separation can be completed in a single operation, lasting only a minute, from solvent extraction to preparation for gamma-ray spectrometry. As a demonstration of the rapid operation of the LMES, fission products were each separated into several categories after three stages of operation. The extractability in the LMES was comparable to that of traditional methods, and the developed method was feasible for rapid separation.

Trace amount of nickel in high-purity iron and iron oxide samples was determined by photon activation analysis (PAA) using the Electron Linear Accelerator at the Research Center for Electron Photon Science, Tohoku University. It was confirmed that about 0.015 μg of nickel in the high-purity iron oxide sample could be determined with an experimental uncertainty of 20% by PAA, that is, it was possible to determine 1% of nickel at least in a few μg of cosmic spherules. PAA was applied to the nickel-determination in cosmic spherules. Nickel in cosmic spherules was determined by PAA more accurately than by instrumental neutron activation analysis done in a reactor neutron spectrum with the fluence rate ratio of thermal neutrons to fast of 4–5 which has so far been applied to the analysis of spherule samples. Additionally, trace amount of nickel in the reference material Giant Clam JCt-1 supplied by the Geological Survey of Japan was determined by PAA with radiochemical treatment.

The hyperfine interactions of99Ru(←99Rh) in YBa2Cu3O7−x withx

The formation cross sections of [sup 10]Be and [sup 26]Al from Al, Fe, Co, Ni, Cu, Zn, Ag, and Au targets irradiated with 12 GeV protons were measured by accelerator mass spectrometry. The obtained cross sections were consistent with the excitation functions predicted from the literature values measured at other proton energies within the experimental uncertainties. The [sup 10]Be cross sections increased with an increase in the target mass. On the other hand, the [sup 26]Al cross sections decreased from Al to Ag targets, but increased somewhat from Ag to Au. The formation mechanisms of [sup 10]Be and [sup 26]Al including [sup 7]Be, [sup 22]Na, and [sup 24]Na are discussed with respect to fitting of the experimental results to the calculated values using the universal formula of Campi [ital et] [ital al]. During the course of the discussion, we introduce a new parameter, the degree of neuton excess ([ital N][minus][ital Z])/[ital A], in order to classify light fragments more clearly.

O-alpha-D-Glucopyranosyl-(1----6)-O-beta-D-glucopyranosyl-(1----6)-1-N- [L-aspart-1-oyl-(L-proline)-4-oyl]-alpha- and -beta-D-glucopyranosylamine have been prepared, as models for a derivative possibly present in the glomerular basement membrane of rats, by condensation of the corresponding D-glucosyl-dipeptide derivatives with 2,3,4,2',3',4',6'-hepta-O-acetyl-alpha-D-isomaltopyranosyl bromide in the presence of mercuric cyanide, followed by deprotection of the trisaccharide-dipeptide derivatives.

A new method to estimate the fast-neutron fluence of the Hiroshima atomic bomb is proposed. 63 Ni produced by the 63 Cu(n, p) 63 Ni reaction provides a unique measure by which to estimate the fast-neutron fluence of the Hiroshima/Nagasaki atomic bombs, because the half-life of 63 Ni is 100 years and 70% of the 63 Ni produced in a copper piece presently exists after 50 years. Using the neutron spectrum given in DS86 and the estimated cross section, we found that a piece of copper of about 10 g which was exposed at a point around 100 m from the hypocenter gives a measurable amount of 63 Ni using a low-background liquid scintillation counter. For the measurement of 63 Ni, accelerator mass spectrometry also seems to be applicable.

Photonuclear production yields of 51 Ti und 51,49,48 Cr from 51 V were redetermined for bremsstrahlung end-point energies ( E 0 ) of 30 to 1000 or 1050 MeV with the aid of radiochemical separation of Cr. The yield curves for 51 Ti, 51 Cr, 49 Cr and 48 Cr show a clear evidence for two components in the production process; one tor secondary-proton reactions at E 0 Q π and the other for photopion reactions, at E 0 > Q , Q π being Q -values for (γ, π + ) and ( γ , π + x n) reactions. The contributions of the secondary reactions for production of the Ti and Cr isotopes at E 0 > Q π were then estimated by fitting calculated secondary yields to the observed ones at E 0 Q π , and found to be about 40%, 20%, 4% and 4% for 51 Ti, 51 Cr, 49 Cr and 48 Cr, respectively, at E 0 = 400 to 1000 MeV. The calculation of the secondary yields was based on the excitation functions for 51 V(n, p) and (p, x ′n) calculated with the ALICE code and the reported photoneutron and photoproton spectra from 12 C and some other complex nuclei. The present results for 49 Cr are close to the reported ones, while the present 48 Cr yields differ by a factor of about 50. For the 51 Ti and 51 Cr yields, there are some discrepancies between the present and reported ones. The yield corrected for the secondaries, in units of μb/equivalent quantum, were unfolded into cross sections per photon, in units of μb, as a function ol monochromatic photon energy with the LOUHI-82 code. The results for the 51 Ti and 49 Cr are in disagreement in both the magnitude and shape with the theoretical predictions based on DWIA and PWIA. A Monte Carlo calculation based on the PICA code by Gabriel and Alsmiller does reproduce the gross feature of the present results.

The nuclide53Mn was produced by the following three nuclear reactions,52Cr(d, n)53Mn,51V(3He n)53Mn and50Cr(α, n), (α, p)53Mn. Enriched52Cr and50Cr metal targets were prepared on copper plate holder by electrodeposition. The commercially available natural vanadium foil was used for the51V(3He, n)53Mn reaction. Each target was bombarded in a cyclotron. Manganese was extracted and purified without using carrier from the bombarded targets by anion and cation exchanges and solvent extraction. The isotopic ratio53Mn/55Mn was measured by mass spectrometry and the amount of55Mn was determined by neutron activation analysis. The activity of53Mn obtained was 7 dpm by 750 millicoulombs in3He bombardment (E3He=20 MeV). The activity due to by-product54Mn was about several thousands times higher than that of53Mn in3He and deuteron bombardments, which were produced through51V(3He, γ)54Mn and53Cr(d, n)54Mn. In alpha bombardment (Eα=15 MeV), the activity of53Mn produced was 8 dpm by 95 millicoulombs. The activity ratio, dpm54Mn/dpm53Mn, was about 3, and this ratio was the best one among the results so far obtained.

A stable radioactive source in vacuo was obtained by a modified horizontal lifting method of Langmuir-Blodgett (L/B) film. In spite of the slight consumption of the substrate solution (only 2–2.5 ml) for preparing a 15 mm×25 mm sized L/B film containing four molecular layers of 109Cd icosanoate, the deposition of the film was complete. The reliability of the deposited films by this method was confirmed by their radioactivities, deposition ratios and autoradiographs. The condition to obtain a larger sized homogeneous L/B film (20–25 mm×102 mm) was also examined. Two or four molecular layers of nonradioactive Cd icosanote deposited on the L/B film of 109Cd icosanoate did not influence the intensity of the γ-ray of 88.0 KeV. Concequently, it is possible to obtain the high radioactive source by the deposition of the multilayers of 109Cd icosanoate. Spectra of L2 and L3 conversion electrons from the 109Cd in its built-up film were also determined. In conclusion, the present depositing method for the L/B film i...

Direct measurement of the β + spectrum of 60 Zn has been carried out with an online isotope separator. Radioactive 60 Zn was produced by the reaction of nat Ni(α, xn) 60 Zn. Emitted β- and γ-rays were measured with a planar type Ge(Li) and a coaxial type Ge(Li) detectors, respectively. Observed β + spectrum was decomposed by the method of Rehfield. The end-point energies of the analyzed spectra were obtained to be 3.082±0.064 MeV and 2.484±0.059 MeV, respectively. Assuming that the highest component of positrons feeds the 62 keV level in 62 Cu, the Q-value of the β + decay of 60 Zn was determined to be 4.166±0.064 MeV.

Langmuir—Blodgett (L/B) films of tritiated fatty acid were prepared to measure the electron antineutrino mass. The measurement requires that a source should be highly radioactive, homogeneous, very thin, uniform, and nonvolatile in vacuo . With regard to the volatility, the L/B film of fatty acid is, in general, not very stable in vacuo , and desorption of the source molecules results in the main background rates of the measurement and reduces the sensitivity of the mass determination. In the present work, we examined the stability of the L/B film in vacuo , and tried to improve the stability of the film by (i) perfect formation and deposition of metal soap molecules that are more resistant against evaporation than the original fatty acid molecules, and (ii) cooling of the 3 H source with liquid nitrogen in order to reduce the evaporation. Finally, a uniform and highly radioactive 3 H source, which is nonvolatile even at a pressure of 10 −4 Pa, was obtained using the Langmuir—Blodgett film of cadmium [ 3 H]icosanoate (sp act 200,000 Ci/mole).

Glucotriosyl asparagine 2, a proposed structure for the glycan part of nephritogenic glycopeptide 1 isolated from the glomerular basement-membrane of rat, was synthesized in regio-and stereo-selective manners starting from α-D-glucopyranosyl azide 8. The key intermediate for this synthesis was designed to be glucotriosyl azide 21, based on retrosynthetic considerations.

The energy-loss spectra of 18 keV electrons in adsorbed residual gas on Langmuir-Blodgett film, made from arachidic acid (C20H40O2) and cooled at temperatures of -10°C, -35°C and -60°C, were measured through use of an electron source that also acted as an adsorbent. In addition, the amount of adsorbed residual gas was estimated from the energy-loss probability.

Large sized and uniformly deposited 169Yb sources were prepared with the following properties: the intensity variation and the deposited thickness were 2, respectively, for the source sizes of 35×45 mm2 and 20×100 mm2 with the deposited activity of 20-50 µCi, as an energy reference source for the neutrino mass measurement at INS. The technical details of the preparation: the processes of chemical separation and purification, and vacuum-deposition, are here reported.