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The northern Abukuma region of Japan is thickly covered by weathered Mesozoic granite. We investigated the vertical distribution of radionuclides ( 10 Be, 26 Al, and 36 Cl) produced by cosmic irradiation of weathered granitic soil collected from this region at a sampling site located 496 m above sea level, at 37°30′52.6″N, 140°40′13.2″E. We mechanically and chemically separated quartz particles from the weathered granitic soil, and purified them. We also analyzed the vertical distribution of 26 Al, 10 Be, and 36 Cl and estimated a long term averaged erosion rates of 0.019 ± 0.001 mm/y from 26 Al, 0.017 ± 0.001 mm/y from 10 Be, and ∼0.01 ± 0.001 mm/y from 36 Cl. These cosmogenic erosion rates are comparable to the rate estimated from a geomorphological evolution model and with the observed sedimentary deposition rate at Abukuma.

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.

Summary We produced 229Th in the nuclear reaction 232Th(γ, p2n) 229Ac, followed by disintegration to 229m,gTh. The 229mTh α-decay was searched for. Alpha-particle events of energy between 4.93 MeV and 5.05 MeV were observed in the separated thorium sample of β-decay products from an actinium source highly purified from the 232Th + γ reaction products. The energies of the α-particles coincide with those expected for 229mTh.

The yields of 7Be and 10Be produced by bremsstrahlung having a maximum energy (E0) of 200 MeV in natCu, natAg and 197Au targets were investigated by the AMS technique at MALT of the University of Tokyo. It was found that the yields at E0=200 MeV were much lower than those at E0⩾250 MeV, obtained in our previous works. A change in the yields of the fragmentation component in the target-mass dependence was observed at E0=200 MeV when compared with those at E0⩾250 MeV. However, the ratios of the fragmentation yield of 10Be to that of 7Be remained unchanged throughout the concerned E0.

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.

SummaryThe reaction yields of 63 radionuclides with the mass numberA= 56 − 135 produced in the photofission of209Bi by bremsstrahlung of end-point energies (E0) from 450 to 1100 MeV have been measured using a catcher foil technique with the aid of intensive chemical separation. The charge distribution was well reproduced by a Gaussian function with the most probable charge (Zp) expressed by a linear function ofA,i.e.,Zp=RA+S, and with theA-independent full width at half maximum (FWHMCD). The charge distribution parametersR,Sand FWHMCDwere independent ofE0above 600 MeV, reflecting the resonance nature in photonuclear reactions at intermediate energies. The weighted mean values atE0≥ 600 MeV wereR= 0.421 ± 0.001,S= 0.6 ± 0.1 and FWHMCD= 2.1 ± 0.1 charge unit (c.u.). The numbers of pre- and post-fission neutrons were deduced to be νpre= 12 ± 1 and νpost= 1.4 ± 0.3, respectively, assuming the Unchanged Charge Distribution (UCD). Based on the charge distribution parameters, the symmetric mass yield distributions with the most probable massApof 96 ± 1 mass unit (m.u.) and the width FWHMMDof 33 ± 1 m.u. were also obtained. The characteristics of the charge and mass yield distributions are discussed by referring to those for197Au based on the results of calculations using the Photon-induced Intranuclear Cascade Analysis code combined with the Generalized Evaporation Model (PICA3/GEM).

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 recoil properties of 14, 24, 26, 31, 21 and 20 radionuclides formed in photospallation reactions onnatV,natCu,93Nb,natAg,natTa, and197Au, respectively, induced by bremsstrahlung of end-point energies (E0) from 600 to 1100 MeV, have been investigated using the thick-target thick-catcher method based on the two-step vector model. The measured forward-to-backward ratios (F/B) were found to be independent of the mass difference (ΔA) between a product (Ap) and a target (At) and also of At. The recoil velocities ν from the first step and the mean kinetic energies T of the residual nuclei in the second step were deduced and discussed by comparing with the reported results on proton-induced reactions. A comparison with T values calculated by the PICA (Photon-Induced Intranuclear Cascade Analysis) code at E0= 400 MeV was also performed. It was found that although the code well reproduces the experimental results ofnatV andnatCu, the same calculation for heavier targets gives T values lower than the experimental results, indicating some nuclear-structure effect, such as a medium effect notably at At≥ 100. The parameter values of εs= T/(ΔA/At), the average kinetic energy of the emitted particles in a random-walk process of both the photon- and proton-reactions, were found to increase along with an increase of At, but change slopes to become constant above At= 100.

In our previous work, we have measured the neutron spallation cross sections of 12C and 209Bi in the 20-to 150-MeV energy range. Here in this succeeding study, the neutron activation cross sections on spallation reactions for 59Co and natCu have been measured in the quasi-monoenergetic p-7Li neutron fields in the 40-to 120-MeV energy range which have been established at two cyclotron facilities of Takasaki Research Establishment of Japan Atomic Energy Research institute (TIARA) and the Institute of Physical and Chemical Research (RIKEN). The neutron spectrum has been measured with the TOF (Time of Flight) method using an organic liquid scintillator, and the absolute value of peak neutron fluence has been determined from the proton recoil counter telescope at TIARA and the activation method of lithium target at RIKEN. In this study, the following seventeen neutron activation cross section data are reported which produce 56Mn, 54Mn, 52Mn, 58Co, 57Co, 56Co, 55Co, 59Fe from 59Co reactions and 56Mn, 59Fe, 60Co...

The extraction distributions of Am, Cm and lanthanides between tri-butyl phosphate solution and molten calcium nitrate tetrahydrate (Ca(NO 3 ) 2 ·4H 2 O) were studied radiochemically. The apparent equilibrium constants of the extraction reaction were determined and their systematics along the series was studied. By comparing the observed systematics with those obtained for other similar extraction systems it was found that there is a large difference in hydration effect between the lighter and heavier f-series in water-deficient hydrate melt systems.

For the development of a pyrochemical group-partitioning process of actinides and lanthanides, the equilibrium distributions of these elements were measured in some typical binary phase systems of molten salt and liquid metal. A LiCl-KCl mixture was selected as the salt phase, and Zn and Bi were examined as the metal phase. Generally speaking, actinides were more reducible and extractable from the salt phase into the metal phase than lanthanides, and the group partitioning of these elements was feasible in these systems. However, the separation factors which were the ratios in the distribution coefficient between actinides and lanthanides were found to be different in different systems due to different alloying energies. The thermodynamic quantities of actinides and lanthanides were evaluated from the equilibrium distributions and discussed in some detail.

A p-7Li quasi-monoenergetic neutron field for activation experiment has been developed at energies between 18 and 38 MeV. The absolute neutron intensity was accurately determined from the number of 7Be nuclei produced in the 7Li target which is equal to the number of the monoenergetic peak neutrons released in the 4π direction. The angular distribution function of the peak neutrons is necessary for the estimation of the monoenergetic neutrons emitted in the forward direction for the sample irradiation. The distribution function was measured for proton energies of 20, 30 and 40 MeV and was collected from papers for energies between 25 and 800 MeV to get the universal curve. Activation experiments of various natural and enriched samples were performed at this quasi-monoenergetic neutron field. Here we show the neutron activation cross sections of the 197Au(n, 2n)196Au, 197Au(n, 4n)194Au and 59Co(n, 2nα)54Mn reactions as examples.

AMS has been applied to many application researches at the new tandem accelerator facility of the University of Tokyo since April of 1995. The reproducibility of the measurements has not been good enough especially for 14 C-AMS, although, the larger acceptance of the stripper canal is found useful for it to be better. The minimum detection sensitivity is on the level of practical use.

Analysis of 99Tc in the environment have been interested because of a long term radioecological effect of 99Tc due to its long half-life. One of the problems on 99Tc analysis is a tracer since there is no stable isotope in Tc. Development of 99Tc determination by ICP-MS enables us to use 95mTc as a yield monitor. The radiochemical yield is evaluated by gamma spectrometry of 95mTc and 99Tc is determined by mass spectrometry without any in-terference by 95mTc tracer added to the sample. We produced 95mTc without 99Tc by an irradiation of metal Nb with 40MeV alpha particles using cyclotron. The 0.1 mm thickness Nb foil stacked 4 pieces was irradiated for 21 h at beam current of 1.5μC, dissolved in a mixture of HNO3 and HF, and 95mTc was isolated and purified chemically. No contamination of 99Tc was confirmed on 95mTc fraction.

The hyperfine interactions at {sup 99}Ru({sup $IMP@99}Rh) dispersed in YBa{sub 2}Cu{sub 3}O{sub 6.8} and YBa{sub 2}Cu{sub 3}O{sub 6} were studied by means of time-differential perturbed-angular-correlation (TDPAC) and emission Moessbauer spectroscopy. The TDPAC and Moessbauer measurements show that Ru ions are in the tetravalent state and exclusively occupy the Cu-1 sites, which form one-dimensional Cu-O chains in the orthorhombic phase. The oxygen coordinations around the Ru ions are discussed on the basis of the observed electric field gradients at {sup 99}Ru in YBa{sub 2}Cu{sub 3}O{sub 6.8} and YBa{sub 2}Cu{sub 3}O{sub 6}. 35 refs., 6 figs., 1 tab.

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.

The electrochemical calorimetry of the electrolysis of D2O has been carried out using a Pd cathode in an undivided, open cell fashion, together with measuring the total volume of the evolved gases....

A radiochemical procedure has been established to dope carrier-free 99Rh in YBa2Cu3O7−x. The time-differential perturbed-angular correlation of γ-rays emitted from the nuclear excited levels of the daughter nuclide 99Ru in the superconducting and semiconducting samples with x99Ru is a useful hyperfine-interaction probe comparable to 57Fe.0.2 and 1.0, respectively, revealed the hyperfine electric quadrupole interaction for the former and the magnetic interaction in addition for the latter. The results have shown that

Neutron emission caused by the spontaneous appearance of a hole state in a nucleus, which could take place as a manifestation of violation of the Pauli principle, was searched for. Neutrons from natural lead were found to be less than 1.6*10-3 neutrons/s kg which gives a lifetime of tau >1.0*1020 y (0.99 CL). It is shown that the present measurement limits spontaneous appearance of a hole state better than the measurement of nuclear gamma -transitions by many orders of magnitude.

A third measurement of the electron antineutrino mass by tritium beta decay at INS was carried out after making some improvements for enhancing the counting rate. Langmuir-Blodgett film beta -ray sources with a 5-times larger area (60*200 mm2) than those used in previous measurements were prepared, and a new position sensitive beta -detector with a 6-times larger sensitive area was developed. Using this modified equipment, about 150000 events, more than one order of magnitude higher numbers than in previous measurements, were accumulated in the last 100-eV region below the end-point energy.

Radiochemical yield measurements are reported for barium isotopes from $^{133}\mathrm{Cs}$(\ensuremath{\gamma},${\mathrm{\ensuremath{\pi}}}^{\mathrm{\ensuremath{-}}}$xn${)}^{133\mathrm{\ensuremath{-}}\mathit{x}}$Ba for x=0, 2, 4, 5, 6, 7, and 9 for bremsstrahlung maximum end-point energies ${\mathit{E}}_{0}$=30--1050 MeV and for $^{133}\mathrm{Xe}$ from $^{133}\mathrm{Cs}$(\ensuremath{\gamma},${\mathrm{\ensuremath{\pi}}}^{+}$${)}^{133\mathit{m},}$gXe for ${\mathit{E}}_{0}$=300--1000 MeV. Emphasis was placed on Ba measurements near the pion threshold and for different target thicknesses in order to assess interfering secondary particle-induced reactions. Clear evidence of secondary reactions was found in the form of a shoulder in the yield curves for a range of values near ${\mathit{E}}_{0}$\ensuremath{\lesssim}${\mathit{Q}}_{\mathrm{\ensuremath{\pi}}}^{\mathrm{\ensuremath{-}}}$, the ${\mathit{Q}}_{\mathrm{\ensuremath{\pi}}}^{\mathrm{\ensuremath{-}}}$ value of $^{133}\mathrm{Cs}$(\ensuremath{\gamma},${\mathrm{\ensuremath{\pi}}}^{\mathrm{\ensuremath{-}}}$xn) reaction. This result was used for the correction of yields at ${\mathit{E}}_{0}$\ensuremath{\gtrsim}${\mathit{Q}}_{\mathrm{\ensuremath{\pi}}}^{\mathrm{\ensuremath{-}}}$ with the aid of reported measurements of photoproton spectra from $^{12}\mathrm{C}$ and other complex nuclei and cross sections of ${(}^{133}$Cs+p) reactions. The yields corrected for the secondaries ${\mathrm{\ensuremath{\sigma}}}_{\mathit{q}}$(${\mathit{E}}_{0}$) were unfolded into cross sections per photon of energy k, \ensuremath{\sigma}(k). The characteristic features of ${\mathrm{\ensuremath{\sigma}}}_{\mathit{q}}$(${\mathit{E}}_{0}$) and \ensuremath{\sigma}(k) are then discussed in terms of ${\mathit{E}}_{0}$ and k dependences and product mass (${\mathit{A}}_{\mathit{p}}$=133-x) by comparing the present results with those for other systems currently obtained by our group. It was found that the present results of \ensuremath{\sigma}(k) are generally reproduced by a cascade-evaporation calculation based on the pica code of Gabriel and Alsmiller, only if the calculated values are shifted up in photon energy by 30 MeV and the neutron cutoff energy is chosen to be 1 MeV.

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.

The electrochemical calorimetry of the electrolysis of D2O has been carried out using a Pd cathode in an undivided, open cell fashion, together with measuring the total volume of the evolved gases....

A technique for preparing nuclear reaction targets of various thicknesses was developed by using common filtration technique of hydroxide precipitates with a porous Al(2)O(3) membrane filter. Uniformity was found to be within a few % in each thickness. Durability for beam irradiation was also confirmed. The preparation procedure is convenient and the method is appropriate for several target materials, including not only precious materials but also radioactive materials with low contamination.

In response to the needs of research groups in Japan, a chemical separation procedure was developed for isolating specific radioactive isotopes from a multitracer prepared by the reaction of 235U fission induced by thermal neutrons. This efficient technique is based on solvent extraction and separates the multitracer isotopes into six groups. It is intended to be used in an automated rapid extraction system.

The Hiroshima and Nagasaki atomic bombs resulted in the worst reported exposure of radiation to the human body. The data of survivors have provided the basis for the risk estimation for ionizing radiation, and thus are widely used as the basis of radiation safety. In this report we have studied a new method to detect the low-level 63Ni activity in copper samples in order to estimate the fast neutron fluence from the Hiroshima atomic bomb. Only 0.8 x 10(-3) Bq g(-1) of 63Ni is expected to be produced by the atomic bomb in a copper sample with the 63Cu(n, p)63Ni reaction at a distance of 500 m from the hypocenter. Our method has the required level of sensitivity for determination of the fast neutron fluence out to distances of at least 500 m, and perhaps as far as 1,000 m. We have already investigated and collected some bomb-irradiated copper samples for further study.

The formation cross sections of tritium from oxygen have been measured in p-Li and p-Be neutron fields installed at the INS SF cyclotron in order to estimate the production of tritium in the cooling water of accelerators. Irradiations were performed with the semi-monoenergetic neutrons produced from the 7Li(p,n) reaction at proton energies (Ep) from 20 up to 40 MeV in 5 MeV steps and those from 9Be(p,n) in 2.5 MeV steps with proton intensities of 2 - 5 (mu) A, which yields from 1011 to 1012 n/cm2 at the target position. The neutron energy spectra were determined by an NE-213 scintillator. The tritium produced in the water used as the oxygen target was extracted by a distillation method, and measured by a liquid scintillation counter. The excitation functions for 16O(n,t)14N reaction obtained by the p-Li and p-Be neutrons agreed well with each other within the experimental uncertainties.© (1995) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Production of a cachexia-inducing factor(s) by the SEKI melanoma cell line, established from a human melanoma, has been well documented. Conditioned medium from cultures of this melanoma cell line contains a factor(s) that inhibits the activity of lipoprotein lipase (LPL) in fully differentiated 3T3-L1 adipocytes. The mode of inhibition of this enzyme by the factor, i.e. its dose-dependency and time course, is very similar to that of LPL-inhibition by a macrophage-derived cachexia-inducing factor, cachectin/tumor necrosis factor (cachectin/TNF). However, the conditioned medium of SEKI melanoma cells does not contain any immuno-reactive substances reactive in enzyme-linked immunosorbent assay (ELISA) with anti-cachectin/TNF antibody, or with anti-interleukin 1 alpha or beta antibodies. This LPL-suppression factor present in the conditioned medium seems to be a peptide because of its heat-lability and apparent molecular weight of more than 25,000. The conditioned media from cultures of four other different cell lines were found to show no significant suppression of LPL activity. These results imply that SEKI melanoma cells produce a cachexia-inducing factor(s) similar to cachectin/TNF but that the molecule involved is different.

A thirty-three year-old woman with systemic lupus erythematosus (SLE) suffered from acute myocardial infarction. Prednisolone 20 mg/day was used because the signs of SLE, such as fever and decreased serum C3, levels, became aggravated on the fifth hospital day of acute myocardial infarction. Fatal cardiac rupture occurred on the twenty-second hospital day. At autopsy, extensive myocardial infarction with coronary artery thrombi and diffuse coronary arteritis were revealed. The rare clinical picture of a fatal cardiac rupture in the later phase of acute myocardial infarction and the precise dosage of prednisolone for her SLE are described.

Neutral glycosphingolipids from urinary sediments of six patients with Fabry's disease and 11 members of the family of one propositus were analyzed using high-performance liquid chromatography. Per-o-benzoyl derivatives of GlcCer, LacCer, GbOse3Cer and GbOse4Cer were clearly resolved by a solvent mixture of hexane/dioxane/isopropanol (75:25:1, v/v) on a normal-phase silica column. Using our isocratic solvent system, the analysis was completed within 15 min. The smallest amount of glycolipid that could be detected by HPLC was 50 pmol and a linear response was shown at 230 nm up to 400 pmol. The calculated peak area of GbOse4Cer was higher than those of GlcCer, LacCer and GbOse3Cer. The molar ratios of GbOse3Cer to monohexosyl ceramide (CMH) in the urinary sediments were: Fabry hemizygotes, 36.33 +/- 25.54 (n = 6); heterozygotes, 0.94 +/- 0.50 (n = 4); and controls, 0.11 +/- 0.06 (n = 5). The molar ratio CDH/CMH was also higher in patients (8.42 +/- 6.23) than in controls (0.77 +/- 0.23). The female H was a rare example of a carrier with typical clinical manifestations. From the urinary sediment analysis, females E, G and J were suspected to be Fabry heterozygotes, although no clinical signs were observed at the time of examination.

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.