Nuclear Data Sheets for A = 215

The evaluated spectroscopic data are presented for 12 known nuclides of mass 215 (Hg, Tl, Pb, Bi, Po, At, Rn, Fr, Ra, Ac, Th, Pa). For ²¹⁵Hg, ²¹⁵Tl, ²¹⁵Pb, and ²¹⁵Pa nuclei, no excited states are known. The decay characteristics of ²¹⁵Hg and ²¹⁵Tl are unknown. The decay scheme of ²¹⁵Pb is considered as incomplete. Ordering of γ cascades in the decay of 36.9–s isomer of ²¹⁵Bi and for high–spin states above 2251 keV in ²¹⁵Fr are not established. High–spin excitations, including several isomeric states, are well known in ²¹⁵Bi, ²¹⁵Po, ²¹⁵Rn, ²¹⁵Fr, ²¹⁵Ra, and ²¹⁵Ac. No particle–transfer reaction data are available for any of the A=215 nuclei.     

Nuclear Data Sheets for A = 198

The 2002 version of Nuclear Data Sheets for A = 198 (2002Zh04) has been updated and revised on the basis of the experimental results from various decay and reaction studies before June 2008. The experimental data for all known nuclei of A = 198 (Ir,Pt,Au,Hg, Tl,Pb,Bi,Po,At,Rn) have been reevaluated. The experimental methods, references, Jπ arguments, and necessary comments are given in the text. The theoretical internal conversion coefficient (ICC) (and its associated uncertainty) for γ-rays have been interpolated from theoretical values based on the “Frozen Orbital” approximation (2002Ba85) using the BRICC(v2.2) computer program. Summary band-structure drawings and level schemes from both radioactive decay and reaction studies are presented. Also of special interest are the new levels of ¹⁹⁸Ir, ¹⁹⁸Tl nuclei and identification of new superdeformed bands in ¹⁹⁸Pb and ¹⁹⁸Po.     

Nuclear Data Sheets for A = 192

Experimental structure and decay data for all nuclei with mass A=192 (Ta, W, Re, Os, Ir, Pt, Au, Hg, Tl, Pb, Bi, Po, At) have been evaluated. This evaluation, covering data received by 15 June 2012, supersedes the 1998 evaluation by C. M. Baglin (Nuclear Data Sheets 84, 717 (1998), literature cutoff August 1998) and the subsequent inclusion in the ENSDF database of the new nuclide ¹⁹²At (C. M. Baglin, literature cutoff 16 May 2006). It also incorporates the current evaluation of superdeformed-band information by B. Singh. Since the last publication, ¹⁹²Ta, ¹⁹²W and ¹⁹²At have been observed, and an isomeric state has been identified in ¹⁹²Re. The ε decay of ¹⁹²Au has been studied using a multidetector array resulting in an extensively revised level scheme for ¹⁹²Pt.     

<Superscript>212</Superscript>Pb/<Superscript>212</Superscript>Bi Generator for nuclear medicine

A scheme for producing the α-emitters ²¹²Pb and ²¹²Bi, to be used in a promising method of diagnostics and therapy in oncology – radioimmunotherapy, is proposed. The technology is based on two generators operating in tandem: ²²⁸Th/²¹²Pb and ²¹²Pb/²¹²Bi. The first one is based on separation from an initial solution containing thorium isotopes and gaseous ²²⁰Rn, which secures the purity of the desired products ²¹²Pb and ²¹²Bi. For a ²²⁸Th/²¹²Pb model generator, the efficiency of ²²⁰Rn extraction from solution was ~60%. After conditioning, the ²¹²Pb solution from the ²²⁸Th/²¹²Pb generator was used to charge a column, which functioned as a ²¹²Pb/²¹²Bi generator, with a cation exchanger.     

Evaluation of decay data of 213Bi

213Bi disintegrates (97.91±0.03) % by β- emission to the levels in 213po, and (2.09±0.03) % through α decay to 209Tl. The evaluation of the complete decay scheme and data of 213Bi including the recent new measurements are presented in this report. The Limitation of Relative Statistical Weight Method (LWM) was applied to average numbers throughout the evaluation. The uncertainty assigned to the average value was always greater than or equal to the smallest uncertainty of the values used to calculate the average. The half-life is determined to be 45.59±0.06 minutes. All known measured gamma-ray relative emission probabilities have been examined. And the gamma-ray emission probability of the reference γ line of 440.44keV is recommended to be (26.1±0.3) %. The calculated internal conversion coefficients and their uncertainties have been used to obtain the complete decay intensity balance. The other decay characteristics are calculated using the ENSDF analysis program. Finally the new 213Bi decay scheme was re-built.     

Nuclear Data Sheets for A = 184

Nuclear structure and decay data for all nuclei with mass number A=184 (Lu, Hf, Ta, W, Re, Os, Ir, Pt, Au, Hg, Tl, Pb, Bi) have been evaluated, and the corresponding level schemes from radioactive decay and reaction studies are presented. This evaluation supersedes the previous publication (R.B. Firestone, Nuclear Data Sheets 58, 243 (1989) (literature cutoff date 1 June 1989)) and subsequent revisions of high spin data for several nuclides by Huo Junde (31 July, 1995) and evaluations by C.M. Baglin for ¹⁸⁴Au, ¹⁸⁴Pb and the new nuclide ¹⁸⁴Bi (literature cutoff dates 4 April 2003, 28 July 2003 and 21 January 2004, respectively). The present evaluation includes literature available by 1 October 2009. Subsequent to those evaluations, (HI, xnγ) studies have contributed significantly to our knowledge of the structure of ¹⁸⁴Re (2005Wh04), ¹⁸⁴Os (2002Sh21, 2002Wh01, 1998Sh36), ¹⁸⁴Hg (1995De30, 1995Sf01) and ¹⁸⁴Au (2004Zh38). Additional information on the level structure of ¹⁸⁴W has become available from new thermal neutron capture measurements (2003Bo52, 2004Lo22, 2007ChZX), from detailed (p,t) reaction studies (2006Me25), new Coulomb excitation (1991Wu05) and (γ,γ^′) (1993He15) studies, and from the ¹⁹⁸Pt(¹³⁶Xe,Xγ) reaction (2004Wh02); knowledge of ¹⁸⁴Pt has benefited from a new ¹⁸⁴Au ε decay study (2006KrZT, 1992Xu02, 1992Xu06, 1992XuZY), but this decay cannot yet be normalized due to the mixed parentage of the sources used.     

Nuclear Data Sheets for A=182

Nuclear spectroscopic information for known nuclides of mass number 182 (Lu,Hf,Ta,W,Re,Os,Ir,Pt,Au,Hg, Tl,Pb) with Z=71 to 82 and N=111 to 100 have been evaluated and presented together with adopted energies and Jπ of levels in these nuclei. No excited state data are yet available for ¹⁸²Lu, while only limited structure information is available for ¹⁸²Pb and ¹⁸²Tl. Rotational band structures are known for ¹⁸²Hg and ¹⁸²Au but spin-parity assignments remain largely tentative. The decays of ¹⁸²Lu, ¹⁸²Hg, ¹⁸²Au and ¹⁸²Tl are not well established. The ¹⁸²Hf isotope is of geophysical and astrophysical interest. This evaluation supersedes previous full evaluations of A=182 published by 1988Fi05 and 1975Sc13, and a selected (mainly high-spin) update of A=182 published by 1995Si04.     

Nuclear Data Sheets for A = 224

Nuclear structure information for all nuclei with mass number A = 224 is summarized. Evaluated data and the adopted levels and spin and parity assignments are given.Data for ²²⁴Rn and ²²⁴Fr β-decays and ²²⁴Fr decay schemes are from unpublished work by V. P. Afanasev, et al. (1973), and should be considered preliminary.²²⁴Ac ε-decay data and decay scheme are from unpublished work by M. W. Hill (1958), who used Nal crystal to detect photons. A complete, more reliable decay work would be desirable, and would be useful to determine the ²²⁴Ac ground-state spin.α-parents are shown on the drawings above their daughters. α-decay data are given as much as possible on the drawings. Unless otherwise indicated, γ-transitions (photon+ce) intensities are shown. For data with uncertainties and references, see A = 228 compilation in this issue.Neutron- and proton-separation energies, and Q-values for decays shown on the drawings have been taken from 1974 mass adjustment by A. H. Wapstra, K. Bos, ad N. B. Gove.     

γ谱无源效率刻度法测量IAEA国际比对样品

利用γ谱无源效率刻度法对IAEA在2010年-2012年间提供的6个水样、3个土壤样和1个生物灰中的~(241)Am、~(133)Ba、~(60)Co、~(134)Cs、~(137)Cs、~(152)Eu、~(228)Ac、~(40)K、~(208)Tl、~(226)Ra、~(214)Bi、~(212)Pb、~(214)Pb、~(238)U等核素进行了活度浓度分析。测试结果与IAEA的参考值相比,报送的41个数据总体接受率为100%。通过比对结果分析,验证了γ谱无源效率刻度方法的实用性和可靠性,为该方法在环境辐射监测中的广泛应用提供了依据。     

Variation of Intensity of Environmental Gamma-Rays Measured with Ge(Li) Spectrometer

The variation of the intensity of environmental γ-rays has been studied with a Ge(Li) spectrometer. The 12 γ-rays were selected to be examined and typical characteristics of variations were obtained for each γ-rays. The intensity of γ-rays of ²¹⁴Pb and ²¹¹Bi which are ²²²Rn daughter nuclei increases on rainy days to the severalfold value of the average in the case of no precipitation. These variations were observed to be roughly proportional to rainfall rate in a sequence of precipitation. The γ-rays intensity of nuclides of the thorium series and ¹³⁷Cs is nearly constant within about 3% regardless of the weather. Its variation is about equal to the statistical fluctuation of the present measurements. The mean diurnal variations of f-ray intensity were obtained on days without precipitation. The intensity of ²¹⁴Pb and ²¹⁴Bi j-rays fluctuates nearly sinusoidally with an amplitude of about 6% of the average value and the maximum in the early morning.     

Separation of the alpha-emitting radioisotopes actinium-225 and bismuth-213 from thorium-229 using alpha recoil methods

An innovative method has been demonstrated for separating alpha-emitting isotopes for medical radiotherapy applications. The method relies on recoil-ion separation rather than on conventional wet chemistry techniques to separate medical isotopes from their precursor sources. The isotopes ²²⁵Ac and ²¹³Bi have been separated from electro-deposited sources of ²²⁹ThO₂. Separations of ²²⁵Ac were carried out by placing nickel recoil collector foils in firm contact with the ²²⁹ThO₂ sources. One-stage recoil-ion separations of ²²⁵Ac from ²²⁹Th have been performed as well as two-stage separations of ²¹³Bi from previously recoil separated ²²⁵Ac. In addition, a direct recoil separation of ²¹³Bi from ²²⁹Th has been demonstrated. The ²¹³Bi from the one-stage direct separation has a high isotopic purity, but contains small amounts of long-lived ²²⁵Ac alpha activity. The two-stage separations of ²¹³Bi produce high isotopic purity material (>99.9999%), but result in lower isotopic yields. Range-energy calculations have been carried out to determine the yields of recoil ions as a function of alpha-particle energy and ThO₂ thickness. The results of the calculations have been benchmarked with recoil separation measurements carried out using ThO₂ electro-deposits over a range of thickness. A computer code based on the generalized Bateman equations has been developed to allow calculations of the amounts of any isotope in the ²²⁹Th decay chain as a function of recoil separation exposure time and elapsed time after the separation. An excellent match has been obtained between the predictions of the Bateman calculations and the results of recoil separation measurements. The recoil separation method has proven to be a simple and effective way of separating medically useful isotopes such as ²¹³Bi. In addition, the method has been shown to produce no chemical or radioactive wastes, in contrast to radiochemical separation methods, which generate mixed (chemical and radioactive) waste.     

Nuclear Data Sheets for A = 222

The ENSDF evaluation for A=222 mass chain (1996El01) has been updated on the basis of the experimental results, since September 1995 (literature cutoff date in 1996El01), from various reaction and decay studies for all nuclides in A=222 mass chain (Z=84 to 92). A new nuclide (²²²Po) has since been observed. In addition, new measurements have been reported in Rn, Th and Ra nuclides. The results obtained from various theoretical studies are given as comments. The updated level and decay schemes, and experimental decay and reaction data on which they are based, are summarized and presented for all the nuclides with mass number A=222. The adopted values of level energies, level spins and parities are given, and γ-ray energies, intensities, as well as other nuclear properties are presented. The references, Jπ arguments, and necessary comments are given in the text. All Q values have been adopted from 2011AuZZ. Theoretical work of 2009Mo27 was consulted.     

Nuclear Data Sheets for170Pt

Nuclear structure data pertaining to¹⁷⁰Pt have been compiled and evaluated, and incorporated into the ENSDF data file. This evaluation of¹⁷⁰Pt supersedes the previous publication (Coral M. Baglin,Nuclear Data Sheets 77,125 (1996) (literature cutoff date October 1995)), and includes literature available by 17 February 1999. The newly incorporated references are: 98Se20, 98Ki20, 97Ju04, 96Bi07 and 95Au04. Three new data sets have been added, as follows:¹⁷⁴Hg α decay,¹⁷¹Au p decay (1.02 ms), (HI,xnγ).     

Development of Three-Dimensional Numerical Model for 222Rn and its Decay Products Coupled with a Mesoscale Meteorological Model I. Model Description and Validation

A three-dimensional Eulerian numerical model for ²²²Rn and its decay products coupled with a mesoscale meteorological model has been developed and applied to the reproduction of the daily and monthly variations of ²²²Rn concentration, the monthly variation of ²¹⁰Pb deposition in Japan and the temporal variation of gamma dose rate after the cold front passage in the coastal area of the Japan Sea for the verification of model capability. The results are as follows: (1) The model reproduced the monthly variation of surface ²²²Rn concentration in remote islands, but underestimated inland concentration due to a coarse vertical resolution near the surface of the model. (2) The model reproduced the seasonal variation of the observed and the long-term yearly averaged ²¹⁰Pb depositions as long as precipitations are predicted precisely. (3) The model reproduced the rise of gamma dose rate in precipitation accompanied by the cold front passage. In particular, ²²²Rn decay products in melted snow and graupel contributed the rise of gamma dose rate.     

Nuclear Data Sheets for A = 216

Nuclear structure information for all nuclei with mass number A = 216 is summarized. Evaluated data and the adopted levels and spin and parity assignments are given.Only the α—decay mode has been observed for all nuclei in this mass chain. Possible ε—capture and/or β—decay are expected to be quite weak for most of them. An upper limit of 0.6% was set by 68Va18 for ²¹⁶Th ε—decay from α—yields. The compilers estimate any ε—capture decay from ²¹⁶At to ²¹⁶Po to be <1.5×10^?6%; similarly, β—decay from ²¹⁶At to ²¹⁶Rn ground state is expected to be <0.0004%, and allowed β^? to any yet unobserved level in ²¹⁶Rn can be estimated to be <0.005% from expected log ft values.Level scheme information for all nuclei is from α—decays of their parents with A=220. α—parents are shown on the drawings above their daughters. α—decay data are given as much as possible on the drawings. For data with uncertainties and references, see A=220 compilation in this issue.Neutron— and proton—separation energies and Q—values for decays shown on the drawings have been taken from 1974 mass adjustment by A. H. Wapstra, K. Bos, and N. B. Gove.     

Nuclear data sheets for A = 190

Experimental nuclear structure and decay data for nuclides of mass A=190 have been evaluated. This work supersedes the previous evaluation by M. R. Schmorak, published in Nuclear Data Sheets 9, 401 (1973). Because of the new experimental results which are incorporated, the present evaluation involves a complete revision of the level structure of every mass-190 nuclide except ¹⁹⁰Ir. It covers significant new results not included in the recent evaluation by R. E. Doebler and E. Browne (Table of Isotopes, 7th Edition, ed. by C. M. Lederer and V. S. Shirley, p. 1213ff, John Wiley and Sons, Inc. (1978)) for the following nuclides and reactions or decay schemes: ¹⁹⁰Os from ¹⁸⁹Os(n,γ) and Coulomb excitation; ¹⁹⁰Pt from (HI,xnγ) reactions and ¹⁹²Pt(p,t); ¹⁹⁰Au from ¹⁹¹Ir(α,5nγ); ¹⁹⁰Hg from (HI,xnγ) reactions; ¹⁹⁰Tl from ¹⁹⁰Pb ε decays; ¹⁹⁰Pb from ¹⁵⁴Gd(⁴⁰Ar,4nγ). Of the nuclei readily studied by nuclear reactions, little is presently known of the odd-odd ¹⁹⁰Ir, and there are only sketchy, preliminary data on high-spin states of ¹⁹⁰Au, which is expected to have a low-lying 11- isomer whose decay has not been observed. A recent measurement of the g-factor for the 24.1-ns isomer in ¹⁹⁰Hg suggests strongly that this state decays by an unobserved transition, whose existence requires confirmation.     

Measurements of natural radionuclides in soil samples from Upper Egypt

This paper presents the results of natural radioactivity measured for the soil of Qena using gamma-ray spectrometry at ZSR, Hanover University, Germany. Soil samples of radioactive concentrations of ^238U-series （^234Th, ^214pb, and ^214Bi）, 232Th-series （^228Ac, ^212pb, and ^208Tl） and ^40K were analyzed. Three objectives were set： （1） activity levels by surface soft sampling at 0-30 cm depth, （2） dose rates of gamma radiation, radium equivalent, index hazard, and effective dose, and （3） ambient dose rates.     

Determination of (n,2n) Reaction Cross Sections for Some Nuclei with Asymmetry Parameter

The (n,2n) reaction cross sections for targets of ^203,205Tl, ^{204,206,207,208}Pb, ²⁰⁹Bi, ²³²Th and ²³⁸U were calculated both theoretically and semi-empirically. Theoretical calculations were done using two different computer codes: PCROSS computer code for the full exciton model and ALICE/ASH-2006 computer code for the geometry dependent hybrid (GDH) model with the incident neutron energy up to 25 MeV. Semi-empirical calculations were done using formulas derived by several researchers. The obtained results have been discussed and compared with the available experimental data taken from the literature. The different nuclear reaction program codes used in the present study show considerable differences depending upon the selected energy range. Especially PCROSS calculation results show a disagreement above the incident energy of about 16 MeV for all the studied nuclei. Moreover, even though the graphs qualitatively agree in shape, they differ in magnitude below 15 MeV.     

Detailed Evaluation of Natural Gamma-Radiation Field due to Uranium (238U) Series

Peak counting rates of a Ge(Li) detector for γ-rays of interest and exposure rates at 1 m above the ground have been calculated using the soil and air concentration profiles of naturally occurring radionuclides at Tsukuba (Yatabe City, Tsukuba District, Ibaraki Prefecture). Decrease in the peak counting rate for 609 keV ²¹⁴Bi γ-ray above the ground, which was due to diffusion loss of ²²²Rn under the ground, was evaluated to be about 44% of the peak counting rate calculated assuming uniform distribution of ²²²Rn under the ground, and decrease in the exposure rate was evaluated to be about 13% of the total exposure rate calculated assuming uniform distribution. Field measurement of γ-rays from sources in the soil and air was also made with the Ge(Li) detector at Tsukuba. The calculated peak counting rates where the diffusion loss of ²²²Rn was involved agreed with those observed in situ. During the observation the calculated peak counting rate for the 609 keV γ-ray from airborne ²¹⁴Bi ranged 3–19% of that from uniformly distributed ²¹⁴Bi source under ground, and the calculated exposure rate from the airborne ²²²Rn daughters ranged 1–9% of the total exposure rate.     

α放射性核素靶向治疗研究进展:α核素的制备与分离北大核心CSCD

α放射性核素靶向治疗(targeted alpha therapy,TAT)技术作为一种很有前景的肿瘤放疗手段近些年来正不断发展。因α放射性核素具有线性传能密度(linear energy transfer,LET)高、射程短、放射生物学效应和细胞毒性强等特点,TAT在微小肿瘤、散在性肿瘤及发生微转移肿瘤的治疗上展现出了独特的优势。但是,由于可用于TAT的α核素来源非常有限,且其制备和纯化也十分困难,这就导致α核素的获取成为了制约TAT技术发展的主要因素之一。针对α放射性核素靶向治疗中α核素的获取问题,本文从核素的性质、制备技术及分离方法的角度对几种适用于靶向治疗的α放射性核素(^(225)Ac、^(213)Bi、^(212)Pb、^(212)Bi、^(227)Th、^(223)Ra、^(230)U、^(226)Th、^(211)At、^(149)Tb)的研究现状进行了概述。