Absence of proton weak coupling states in93Nb

The reactions⁹³Nb(p, p)⁹³Nb,⁹³Nb(p, n)⁹³Mo, and⁹³Nb(p, p′) through isobaric analog resonances in⁹⁴Mo have been used to study the structure of low-lying⁹³Nb states, specifically the degree to which these states can be described as single protons coupled to the core states of⁹²Zr. Excitation curves were obtained from 5.8 to 7.6 MeV incident proton energy, for eight states in⁹³Nb. Results of this work are compared to results from Coulomb excitation studies,⁹³Nb(n, n′γ),⁹³Nb(d,p),⁹²Zr(³He,d),⁹⁴Mo(d,³He) and other related work.     

Energy levels in 93Mo populated by the 93Nb(p,nγ) reaction

Energy levels of ⁹³Mo have been investigated by means of the ⁹³Nb(p, nγ)⁹³Mo reaction. The excitation functions of the level de-excitation γ-rays were measured with a Ge(Li) detector under proton bombardment in the energy range 3.0 to 5.0 Me V. A detailed γ-ray decay scheme which includes 69 levels and 123 γ-ray lines was constructed from the threshold energies for 64 γ-rays and the γ-ray excitation functions around five isobaric analogue resonances in the ⁹³Nb(p, nγ) reaction. Spin-parity values for 59 levels and favourable values for 8 levels were assigned from the analysis of relative neutron yields via the isobaric analogue resonances of the parent odd-odd nucleus ⁹⁴Nb. The results of the present experiment are compared with shell-model calculations.     

Ba（n，x）~（134）Cs，~（134）Ba（n，2n）~（133）Ba，

用中子活化法相对于５４Ｆｅ（ｎ，Ｐ）５４Ｍｎ反应，在１３．５０—１４．８０ＭｅＶ中子能区测量了Ｂａ（ｎ，ｘ）１３４Ｃｓ，１３４Ｂａ（ｎ，２ｎ）１３３Ｂａ，１４０Ｃｅ（ｎ，２ｎ）１３９Ｃｅ，１４２Ｃｅ（ｎ，２ｎ）１４１Ｃｅ和２３Ｎａ（ｎ，２ｎ）２２Ｎａ的反应截面．并将所测的结果和其他作者的结果进行了比较，中子能量是用９０Ｚｒ（ｎ，２ｎ）８９ｍ＋ｇＺｒ反应和９３Ｎｂ（ｎ，２ｎ）９２ｍＮｂ反应截面比法测定的。     

The 93Nb(p,d)92Nb reaction at 26.3 MeV

The ⁹³Nb(p, d)⁹²Nb reaction was studied at a proton energy of 26.3 MeV. Angular distributions were obtained for outgoing deuterons to 37 states in ⁹²Nb up to an excitation energy of 4.2 MeV. The results were compared with DWBA calculations to extract l-values and spectroscopic factors. Fourteen previously unobserved l = 1 transitions were measured.     

Cross-Section Measurements for Reactions on Platinum Isotopes in the Neutron Energy Range of 13.5 to 14.6MeV

Cross-sections for (n,2n) and (n,p) reactions have been measured on platinum isotopes at the neutron energies of 13.5 to 14.6 MeV using the activation technique. Data were reported for the following reactions: Pt(n,2n)197m+gPt,198Pt(n,2n)197mPt,192Pt(n,2n)191Pt, 194Pt(n,p)194Ir, 195Pt(n, p)195mIr, and 196Pt(n,p)196mIr. At the neutron energies of 13.5, 14.1 and 14.6 MeV, the cross sections in mb are 2038±159, 1919±73 and 1836±68 for 198Pt(n,2n)197m+gPt reaction; 974±37, 1055±39 and 1042±39 for 198Pt(n, 2n)197mPt reaction, respectively. The cross sections are 1680±103, 1810±67 and 2047±97 for 192Pt(n,2n)191Pt reaction, and 1.0±0.2, 1.6±0.2 and 1.8±0.2 for 195Pt(n, p)195mIr reaction, respectively, at energies of 14.1, 14.4 and 14.6MeV. At 14.1 and 14.4 MeV neutron energies, the cross sections are 3.8±0.4 and 5.4±0.5 for 194Pt(n,p)194Ir reaction. While, the data are (1.13±0.07) and (1.18±0.06) mb at energies of 13.5 and 14.4 MeV, respectively, for 196Pt(n,p)196mIr reaction.The neutron fluences were determined using the monitor reaction 93Nb(n, 2n)92mNb or 27Al(n, a)24Na. A comparison was made between the present cross sections and the collected data for the measured reactions.     

Determination of the Products of Irradiation of Natural Molybenum By Deuterons with Energy up to 13 MeV by Means of Semiconductor Gamma- and X-Ray Spectrometry

Introduction

Among the products of irradiation of natural molýbdenum by deuterons with energies up to 13 MeV, by means γ and X-ray speclrometry were identified these radlonudldes: ⁹⁹Nb, ^92mNb, ^95m+gNb ⁹⁶Nb, ⁹⁹Mo, ¹⁰¹Mo, ⁹²Tc, ^93m+gTc, ^94m+g^>Tc, ^95m+gTc, ⁹⁶Tc, ^97mTc, ^99mTc,¹⁰¹Tc, and ⁸⁹Zr. With the more intensive lines of γ transitions of ⁹⁰Nb, ⁹⁶Nb, ^93m+gTc, ^94m+gTc, ^95m+gTc, ⁹⁹Tc and ^97mTc accurate photon energies have been established and for the lines 1475.7 and 1520.5 keV of ⁹³Tc, 820.2 keV of ^95mTc, and 96.4 keV of ^97mTc also the absolute intensities of the emitted γ were determined. By means of aluminium foils, by which the set of Mo foils had been interlaid, the atomic recoil in forward and backward direction ivas established for the 17.82 mg/cm² Mo foils and deuteron energy up to 12.7 MeV and the ion current of 3.4 μA.     

Deeply bound 1s and 2p pionic states in 205Pb and determination of the s-wave part of the pion-nucleus interaction

We observed well-separated 1s and 2p pi(-) states in 205Pb in the 206Pb(d,3He) reaction at T(d) = 604.3 MeV. The binding energies and the widths determined are B(1s) = 6.762+/-0.061 MeV, Gamma(1s) = 0.764(+0.154)(-0.171) MeV, B(2p) = 5.110+/-0.045 MeV, and Gamma(2p) = 0.321(-0.062)(+0.060) MeV. They are used to deduce the real and imaginary strengths of the s-wave part of the pion-nucleus interaction, which translates into a positive mass shift of pi(-) in 205Pb.     

Measurements of the Cross-sections of Produced Short-Lived Nuclei Induced by Neutrons around 14 MeV on Isotopes of Tungsten

New experimental cross-section data for the180 W(n,2 n)179 mW,186 W(n,2 n)185 mW and186 W(n,p)186 Ta reactions at the neutron energies of 13.5 and 14.4 MeV are obtained by the activation technique. The neutron beams are produced by means of the3 H(d,n)4 He reaction. The gamma activities of the product nuclei are measured by a high-resolution gamma-ray spectrometer with a coaxial high-purity germanium detector. The neutron fluence is determined using the monitor reaction93 Nb(n,2 n)92 mNb. The results in the current work are discussed and compared with the measurement results found in the literature. It is shown that these higher accuracy experimental cross-section data around the neutron energy of 14 MeV agree with some previous experimental values from the literature within experimental uncertainties.     

Excited states of 96Nb from the 96Zr(p,nγ)96Nb reaction

The γ-ray spectra of the ⁹⁶Zi(p, nγ)⁹⁶Nb reaction have been measured with Ge(Li) detectors at different bombarding proton energies between 1.3 and 5.1 MeV. γγ coincidences were observed at E_p = 4.7 and 5.0 MeV. On the basis of experimental results a level scheme of ⁹⁶Nb was deduced, and γ-threshold energies and γ-branching ratios were determined. Computed Hauser-Feshbach (p, n′) cross sections have been compared with experimental data obtained from the γ-ray measurements, and level spins and parities have been determined. The energies of ⁹⁶Nb levels were calculated on the basis of the parabolic rule, derived from the cluster-vibration model. The Racah multipole decomposition method was used also for the theoretical interpretation of several ⁹⁶Nb multiplet states.     

A formula used to subtract the effect of gamma-ray of the others to that of measured reaction in measurement of cross section of nuclear reaction and its application

Abstract According to the regulation of growing and decay of artificial radioactive nuclide, a formula used to subtract the effect of characteristic γ-ray of the others to that of measured reaction was deduced. And then the cross sections of 120Te (n, 2n)119mTe reaction induced by neutrons around 14 MeV were measured by activation relative to the 93Nb (n, 2n)92mNb. In the process of the cross sections measured to be calculated, it was subtracted that the effect of characteristic γ-ray of 126Te (n, p)126Sb to that of measured 120Te (n, 2n)119mTe reaction using the formula deduced. The experimental results were (689±37) and (750±41) mb at the neutron energies of (13.5±0.3) and (14.6±0.3) MeV, respectively. Measurements were carried out by γ-detection using a coaxial HPGe detector. As samples, spectroscopically pure tellurium powder has been used. The fast neutrons were produced by the T(d, n)4He reaction. The neutron energies in these measurements were determined by the method of cross-section ratios between 90Zr (n, 2n) 89m+gZr and 93Nb (n, 2n) 92mNb reactions.     

Low-lying states of ~(92,93)Nb excited in the reactions induced by the weakly-bound nucleus ~6Li near the Coulomb barrier

Excited states of odd-odd nucleus ~(92)Nb and odd-A nucleus ~(93)Nb were populated in the 6 Li+ 89 Y reaction with an incident energy of 34 MeV. The processes that produce 92,~(93)Nb and can be measured by a combination of light charged particle and gamma ray measurements are discussed. Twenty new transitions are observed and eight new levels are constructed in ~(92)Nb, and in addition two new transitions are added to the level scheme of ~(93)Nb. Using shell2 model calculations, the low-lying structure of 9 Nb is investigated and compared with the experimental results.     

Cross-section measurement for Ni(n,x)58(m+g)Co,Ni(n,x)60mCo,Ni(n,x)61Co and Ni(n,x)62mCo reactions induced by neutrons around 14MeV

The cross sections of Ni(n,x)58(m+g)CO,Ni(n,x)80mCo,Ni(n,x)61Co and Ni(n,x)62mCo reactions induced by neutrons around [14]MeV were measured in this work and calculated by a previously developed formula in this work.The neutron flux was determined using the monitor reaction 27Al(n,α)24Na and the neutron energies were measured with the method of cross-section ratios for 89Zr(n,2n)89Zr to 93Nb(n,2n)92mNbreactions.     

Isomeric ratios in photonuclear reactions of molybdenum isotopes induced by bremsstrahlung in the giant dipole resonance region

We have determined the isomeric ratios of isomeric pairs ^97m,gNb, ^95m,gNb and ^91m,gMo produced in ⁹⁸Mo(γ, p)^97m,gNb, ⁹⁶Mo(γ, p)^95m,gNb and ⁹²Mo(γ, n)^91m,gMo photonuclear reactions in the giant dipole resonance (GDR) region by the activation method. The results were analyzed, discussed and compared with the similar data from literature to examine the role of excitation energy, neutron configuration, channel effect and direct and pre-equilibrium processes in (γ, p) photonuclear reactions. In this work the isomeric ratios for ^97m,gNb from 14 to 19 MeV, for ^195m,gNb from14 to 24 MeV except 20 and 23.5 MeV and for ^91m,gMo at 14 and 15 MeV are the first time measurements.     

利用TALYS和EMPIRE研究质子诱发钼靶核反应

利用加速器直接生产99Mo和99mTc在核医学领域具有良好的发展前景,精确可靠的核反应数据对于同位素生产具有重要意义.本文通过对EXFOR数据库中natMo(p,x)96m+gTc、100Mo(p,x)99Mo、100Mo(p,2n)99mTc核反应截面实验数据进行分析,采用多项式拟合实验数据给出参考值.并利用TALY...     

Gamma decay of93Mo states from92Mo (d,pγ) and93Tc β-decay

The decay scheme of the fragmented single neutron states of93Mo up to 3.2 MeV excitation energy is obtained from a⁹²Mo(d,pγ)⁹³Mo coincidence experiment. The total γ-spectrum from⁹²Mo+d shows additional strong γ-decays following the β-decay of⁹³Tc produced by the (d, n) reaction. The decay scheme is discussed in the frame of the particle-core coupling model. The important role of 2⁺ core excited components inE2 andM1 transitions between states with different angular momentum of the single particle component is pointed out.     

Observation of the double-charge-exchange reaction48Ca(32S,32Si)48Ti atE lab=125 MeV

The impact parameter (b) dependence of K-shell vacancy production probability for 1,5 MeV/u Nb on Mo collisions has been measured. Consistent with previous experiments on other high Z collision systems, the shape of the b-dependence shows significant deviations from the two-state 2p?-2pσ rotational coupling model.     

Energy levels of92Nb from 92Zr(p,nγ)92Nb

The energy levels of⁹²Nb were studied by means of the⁹²Zr(p, nγ) reaction. The deexcitation γ-rays were observed with a high-resolution Ge(Li) detector in the proton energy range 3.00–4.80 MeV in steps of about 25 keV. Many new excited states of ⁹²Nb were populated by this reaction. Excitation energies up to 1.77 MeV were determined with high precision, and a level scheme of ⁹²Nb is proposed. From a Hauser-Feshbach analysis, the γ-decay scheme and other information, the spin-parities of many levels were assigned.     

Spectroscopy of C

The ¹⁴C(t, p)¹⁶C reaction locates five new states in ¹⁶C, at excitation energies of 3120 ± 15, 3983 ± 10, 4136 ± 10 and 6109 ± 15 keV, in addition to the g.s. and 1.76 MeV states. The 3.02 and 3.98 MeV states appear to be the second 0⁺ and 2⁺ 2p-2h states, respectively. The 4.14 MeV state has J^π = 4⁺ and the 6.11 MeV state has J^π = 2⁺, 3⁻, or 4⁺.     

Low-energy enhancement in the photon strength of 95Mo

A new experimental technique is presented using proton-γ-γ correlations from (94)Mo(d,p)(95)Mo reactions which allows for the model-independent extraction of the photon strength function at various excitation energies using primary γ-ray decay from the quasicontinuum to individual low-lying levels. Detected particle energies provide the entrance excitation energies into the residual nucleus while γ-ray transitions from low-lying levels specify the discrete states being fed. Results strongly support the existence of the previously reported low-energy enhancement in the photon strength function.     

Cross-section measurement for the ~(93)Nb(n,2n)~(92g)Nb reaction at the neutron energy of 14.6 MeV by the AMS method

The cross-section for the~(93)Nb(n,2n)~(92g)Nb reaction has been measured at the neutron energy of 14.6 Me V using neutron activation and accelerator mass spectrometry(AMS)determination of the long-lived product nuclide~(92g)Nb.The neutron energy was generated from the D+T neutron source at the China Institute of Atomic Energy(CIAE).The neutron flux was monitored by measuring the activity of~(92m)Nb produced in the competing reaction channel of~(93)Nb(n,2n)~(92m)Nb.At the neutron energy of 14.6 MeV,the~(93)Nb(n,2n)~(92g)Nb reaction cross-section of(736±220)mb was obtained for the first time.