Experimental data are used to determine the first-forbidden matrix elements for the 2.2-MeV $\beta$ transition of ${\mathrm{La}}^{140}$. The results show that the matrix-element ratio ($\frac{\int \overrightarrow{\alpha }}{\int i\overrightarrow{\mathrm{r}}}$) does not agree with the usual theoretical prediction which assumes the Ahrens-Feenberg approximation. The size of the experimental vector-matrix-element ratio can be understood on the basis of significant off-diagonal contributions in the Coulomb Hamiltonian. The theory of conserved vector current is used to investigate impurities in the isobaric analog to the ground state of ${\mathrm{La}}^{140}$. In addition, the contribution of third-forbidden matrix elements to the transition is investigated.

The failure to observe fission tracks in old Pb-rich and Au-rich minerals restricts the spontaneous fission rates of Au and Pb to ≲1×${10}^{-25\mathrm{}}$ per year per Au atom and <3×${10}^{-24\mathrm{}}$ per year per Pb atom (at 95% confidence level). No fission-track evidence for superheavy elements in these or other minerals rich in heavy elements has been found. These negative results are not compatible with recent proportional-counter data and track data of Flerov and co-workers.

The lifetimes of the 1.38-MeV $0^{+}$ state in ${}_{}{}^{92}{}_{}{}^{}\mathrm{Zr}$ and the 1.30-MeV $0^{+}$ state in ${}_{}{}^{94}{}_{}{}^{}\mathrm{Zr}$ were measured by a particle-$\gamma$ delayed coincidence technique. These states were excited with the ($p, p^{\prime }$) reaction at proton analog-resonance energies of 7.90 MeV for ${}_{}{}^{92}{}_{}{}^{}\mathrm{Zr}$ and 8.12 MeV for ${}_{}{}^{94}{}_{}{}^{}\mathrm{Zr}$. The mean lifetimes obtained from the logarithmic slope of the time spectra are $\tau =240\mathrm{}\pm 40$ psec for the 1.380-MeV state in ${}_{}{}^{92}{}_{}{}^{}\mathrm{Zr}$ and $\tau =462\mathrm{}\pm 30$ psec for the 1.30-MeV state in ${}_{}{}^{94}{}_{}{}^{}\mathrm{Zr}$. For both of these measurements the prompt-resolution function was obtained simultanously with the $0^{+}$ decay curve by observing the short-lived time spectrum for the first excited $2^{+}$ state.

New half-life values are given for ${}_{}{}^{145}{}_{}{}^{}\mathrm{Eu}$, ${}_{}{}^{146}{}_{}{}^{}\mathrm{Gd}$, ${}_{}{}^{149}{}_{}{}^{}\mathrm{Eu}$, ${}_{}{}^{151}{}_{}{}^{}\mathrm{Tb}$, ${}_{}{}^{153}{}_{}{}^{}\mathrm{Sm}$, ${}_{}{}^{153}{}_{}{}^{}\mathrm{Tb}$, ${}_{}{}^{153}{}_{}{}^{}\mathrm{Dy}$, ${}_{}{}^{155}{}_{}{}^{}\mathrm{Tb}$, and ${}_{}{}^{155}{}_{}{}^{}\mathrm{Dy}$. Absolute abundances are reported for prominent $\gamma$ rays associated with the decay of ${}_{}{}^{143}{}_{}{}^{}\mathrm{Pm}$, ${}_{}{}^{146}{}_{}{}^{}\mathrm{Gd}$, ${}_{}{}^{149}{}_{}{}^{}\mathrm{Pm}$, ${}_{}{}^{149}{}_{}{}^{}\mathrm{Eu}$, and ${}_{}{}^{153}{}_{}{}^{}\mathrm{Dy}$.

The structure of ${}_{}{}^{208}{}_{}{}^{}\mathrm{Pb}$ has been investigated using the ${}_{}{}^{209}{}_{}{}^{}\mathrm{Bi}(d, {}_{}{}^3{}_{}{}^{}\mathrm{He}){}_{}{}^{208}{}_{}{}^{}\mathrm{Pb}$ reaction at 50 MeV. Angular distributions have been measured from 10-50° lab for 15 levels in ${}_{}{}^{208}{}_{}{}^{}\mathrm{Pb}$. These states in ${}_{}{}^{208}{}_{}{}^{}\mathrm{Pb}$ are considered to be populated through their [$1h_{\frac{9}{2}}$, ${\mathrm{}\left(\mathrm{nlj}\right)\mathrm{}}^{-1\mathrm{}}$] proton particle-hole components. Spectroscopic factors have been extracted for each state and compared with those predicted by a recent random-phase-approximation calculation of Kuo and Brown. Generally good agreement between theory and experiment results.

The excited levels of ${\mathrm{In}}^{109}$ have been investigated from the decay of ${\mathrm{Sn}}^{109}$ with high-resolution Ge(Li) and Si(Li) detectors and with standard scintillation counters. ${\mathrm{Sn}}^{109}$ was produced by the ($\alpha , n$) reaction on enriched ${\mathrm{Cd}}^{106}$. $\gamma$ rays of the following energies (in keV) and intensities have been assigned to the decay of ${\mathrm{Sn}}^{109}$: 119(<1), 223(∼2), 330.5(17.1), 335(4.5), 345(3), 390(6.4), 437(4.6), 442(5), 526(5.5), 609(2), 649.5(68), 725(1.5), 790(∼2), 839(0.7), 843(0.6), 872(∼1), 950(<1), 1028(17.8), 1037(12.7), 1098(100), 1120(9.1), 1221(0.7), 1321 (37.4), 1443(1.8), 1465(33.8), 1488(17.8), 1497(∼1), 1574(18.8), 1618 and 1622(2.5), 1688(2.0), 1712(1.9), 1729(2.6), 1741(1), 1762(3.5), 1823(1.5), 1841(<1), 1912(15.5), 1930(1.4), 1935(0.3), 1944(3.1), 1952(0.3), 1963(0.1), 1976(0.2), 2053(5.8), 2126(3.6), 2160(2.3), 2193(3.7), 2275 and 2278(1.6), 2349(<1), 2541(7.9), 2595(1.5), 2786(3.9), 2811(0.8), 2860(2.3), 2939(0.27), 3010(0.37), 3033(0.37), 3050(0.97), 3062(0.23), 3074(0.08), 3314(0.22), 3360(0.07), and 3393 (0.35). The use of two Ge(Li) detectors in coincidence studies has revealed the presence of several previously unreported transitions. Based on $\gamma -\gamma$ and $\beta -\gamma$ coincidence results, a consistent level scheme of ${\mathrm{In}}^{109}$ is given. The spin and parity assignments of some of the low excited levels of ${\mathrm{In}}^{109}$ are discussed.

A new high-spin isomer ${}_{}{}^{179m_2}{}_{}{}^{}\mathrm{Hf}$ has been produced by irradiation of isotopically enriched ${}_{}{}^{176}{}_{}{}^{}\mathrm{Yb}$ with $\alpha$ particles. To investigate its decay, Ge(Li) $\gamma$-ray spectra, Si(Li) conversion-electron spectra, and NaI(Tl)-Ge(Li) and Ge(Li)-Ge(Li) $\gamma -\gamma$ coincidence spectra have been recorded. $\gamma$ rays with energies 122.7, 146.2, 169.8, 192.8, 217.0, 236.6, 257.5, 268.9, 316.0, 362.6, 409.8, and 453.7 keV have been attributed to the decay of the isomer. These decay with a half-life of (29±1) day. The coincidence measurements establish that the quanta with energies 122.7 through 236.6 keV are in cascade, while the $\gamma$ rays with energies 268.9 through 453.7 keV represent crossover transitions within a rotational band with levels up to $I=\frac{21}{2}$ built on the ${}_{}{}^{179}{}_{}{}^{}\mathrm{Hf}$ ground state. The rotational-model quantity $\frac{{(g_K-g_R)}^2}{{Q_0}^2}$ has been derived from $\gamma$ intensity measurements of the cascade and crossover transitions. It is constant within the experimental error for all members of the band. The values for the gyromagnetic ratios $g_K=-0.202\mathrm{}\pm 0.027$ and $g_R=0.160\mathrm{}\pm 0.014$ have been deduced.

Neutron transmission measurements have been carried out for ${\mathrm{Dy}}^{161}$, ${\mathrm{Dy}}^{162}$, ${\mathrm{Dy}}^{163}$, and ${\mathrm{Dy}}^{164}$, employing the fast-chopper facility of the Brookhaven Graphite Research Reactor. The $s$-wave neutron strength functions ($S^0$), resonance parameters, average level spacings, and potential-scattering radii have been determined. The values of the neutron strength functions of ${\mathrm{Dy}}^{161}$, ${\mathrm{Dy}}^{162}$, ${\mathrm{Dy}}^{163}$, and ${\mathrm{Dy}}^{164}$ are 1.85 ± 0.15, 2.3 ± 0.5, 1.7 ± 0.2, and 1.2 ± 0.5, all in units of ${10}^{-4\mathrm{}}$. The corresponding average total radiation widths of Dy isotopes are found to be 114 ± 10, 155 ± 15, 109 ± 8, and 55 ± 3 meV. A correlation between total radiation width and $S^0$ seems to be evident. Furthermore, examination of the present and previous results for the rare-earth isotopes indicates that there is a systematic trend of decrease of $S^0$ with increasing mass number for the even-even target nuclei. Absorption-resonance integrals and thermal cross sections are computed from the resonance parameters and are compared with direct measurements of other experiments.

Levels in ${}_{}{}^{110}{}_{}{}^{}\mathrm{Cd}$ have been studied through the decay of ${}_{}{}^{110g}{}_{}{}^{}\mathrm{Ag}\left(1^{+}\right)$ using NaI(Tl) and Ge(Li) detectors. The following $\gamma$-ray energies (intensities in parentheses) were observed: 657.8 ± 0.2(100), 815.6 ± 0.3(0.98), 1125.9 ± 0.3(0.36), 1186.4 ± 0.7(0.056), 1421.8 ± 1.3(0.044), 1475.8 ± 1.3(0.11), 1630.0 ± 1.2(0.048), 1674.2 ± 0.9(0.15), and 1783.3 ± 1.3(0.17) keV. Coincidence measurements performed with a NaI(Tl)-Ge(Li) system showed peaks at 816 and 1126 keV in coincidence with the 657.8-keV line. The 815.6-keV peak in the singles spectrum is a doublet composed of the 818.00-keV component depopulating the $2^{+}$ state at 1475 ± 0.05 keV and a 815.5-keV $\gamma$ ray. It is proposed that the low-energy component depopulates the twophonon, $0^{+}$ level at 1473.2 ± 0.3 keV. A level at 1783.6 ± 0.3 keV is also assigned and estimates of $log\mathrm{ft}$ values to all levels are given. Using a multichannel analyzer in the multiscalar mode, the half-life of ${}_{}{}^{110g}{}_{}{}^{}\mathrm{Ag}$ was measured as 24.7 ± 0.7 sec.

Measurements of the intensities of $K$ x rays in coincidence with fission were carried out in an experiment in which the energies of complementary fission fragment pairs and $K$ x rays were recorded event by event, using a multiparameter analyzer. Subsequent analysis of the data resulted in the determination of the x-ray intensities associated with intervals of fragment mass for each contributing element. Most probable charge and mass values for the emission of $K$ x rays were determined, and it was found that these most probable masses could be used to adequately define the $Z_p$ curve - without appreciable biasing due to details of nuclear structure. An examination of the effect of total kinetic energy on the x-ray distribution revealed a distinct enhancement of even-$Z$ $K$ x-ray contributions to the yields as the total kinetic energy increases. Apparent shifts in the values of most probable masses for the emission of $K$ x rays were also observed as a function of total kinetic energy.

The differences between various microscopic theories of isobaric analog resonances are exhibited. It is shown that the physical assumptions underlying the recent theory of Zaidi and Dyer are identical to those used in the formulation of Mekjian and MacDonald.

Proton elastic scattering data at 30.3 MeV are analyzed using the optical model recently developed by Greenlees, Pyle, and Tang. The present analysis differs from that given in the original paper in using a model-exact treatment of the spin-orbit and isospin terms of the potential. The quality of the fits obtained is insensitive to the detailed manner in which the potential is constructed and, in particular, to the choice of nucleon-nucleon force parameters. These parameters are therefore taken from an analysis of low-energy nucleon-nucleon scattering data, thus enabling the present analysis to give nuclear-neutron rms radii. The $n-p$ rms-radius difference is about zero for medium-weight elements and 0.1-0.2 F for heavy elements. Evidence is presented supporting the conclusion that the volume integral and the rms radius of the real central potential are the well-defined quantities which can be deduced from analyses of elastic proton scattering data.

The four-particle-four-hole state in ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$ and the corresponding states in the even-even, $N=Z$ nuclei of the $2s-1d$ shell have been investigated in the framework of the Hartree-Fock approximation. Detailed calculations were performed in each case to determine the most stable Hartree-Fock solution. By assuming a simple model, the excitation energies of the band heads were calculated showing that ${}_{}{}^{24}{}_{}{}^{}\mathrm{Mg}$ is the last nucleus where a state analogous to the four-particle-four-hole state in ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$ might be observed. Energy levels have been calculated in ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$, ${}_{}{}^{20}{}_{}{}^{}\mathrm{Ne}$, and ${}_{}{}^{24}{}_{}{}^{}\mathrm{Mg}$ using a basis of good angular-momentum states. A comparison between the predicted and the observed energy spectrum has been shown. In ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$, calculations have been performed both with phenomenological and realistic interactions and the results have been compared. The accuracy of the projected angular-momentum states from the twelve-particle-four-hole solution in ${}_{}{}^{24}{}_{}{}^{}\mathrm{Mg}$ has been estimated and shows that the projected states in this case are close to the eigenstates. We have demonstrated that one of two $0^{+}$ states observed around 7 MeV in ${}_{}{}^{20}{}_{}{}^{}\mathrm{Ne}$ is an eight-particle-four-hole state.

The nuclear polarization effect in muonic atoms is calculated for ${}_{}{}^{208}{}_{}{}^{}\mathrm{Pb}$ and ${}_{}{}^{40}{}_{}{}^{}\mathrm{Ca}$. The nuclear intermediate states of ${}_{}{}^{208}{}_{}{}^{}\mathrm{Pb}$ are collective particle-hole states calculated from realistic nucleon-nucleon forces. The total effect is an increase of binding of 6.0±0.6 keV for the $1s$ level, 1.9±0.2 keV for the $2p$ level, and 1.2±0.2 keV for the $2s$ level. We are able to set the uncertainties of the calculation at the relatively small values given above for the following reasons: The muonic intermediate states are treated exactly with the reference-spectrum method; the energies of nuclear intermediate states of $l>\mathrm{}2\mathrm{}$ turn out to be small compared with muonic intermediate state energies; the nuclear dipole states have been well studied experimentally and theoretically; and the nuclear monopole polarization calculated from the particle-hole states has been checked with a Thomas-Fermi theory which gives the observed surface thickness and the surface energy. Similar calculations for ${}_{}{}^{40}{}_{}{}^{}\mathrm{Ca}$ give the correction to the $1s$ level as 0.2 keV. Henley and Cooper's closure approximation, which leads to a large correction of 58 keV to the ${}_{}{}^{208}{}_{}{}^{}\mathrm{Pb}$ $1s$ level, is repeated with two of the following improvements: The intermediate muonic states in the continuum are treated properly, and the two-nucleon cross terms in the ground-state nucleus are included. The correction then comes down to 6 keV.

The analysis of muonic x-ray spectra in deformed nuclei was carried out in the past by diagonalizing the electric quadrupole interaction between the spin doublets ($2p_{\frac{3}{2}}, 2p_{\frac{1}{2}}$), ($3d_{\frac{5}{2}}, 3d_{\frac{3}{2}}$) and the lowest rotational band of the nucleus. With the present experimental accuracy, this procedure is no longer adequate. To take into account the muonic and nuclear states not included in the diagonalization, we renormalize the electric quadrupole interaction by virtual excitations into those states. We find that the renormalization correction amounts to a few percent of the quadrupole matrix elements. This explains the systematic tendency for the intrinsic quadrupole moments obtained from the traditional analysis to be a few percent larger than the values deduced from Coulomb excitation experiments. We also find that the inclusion of the renormalization corrections has a very significant effect on the parameters of the charge distribution and the intensity ratios of the hyperfine multiplets.

Precise measurements, using a stable high-resolution Ge(Li) spectrometer, have been made of the $K(2p-1s)\mathrm{}$ and $L(3d-2p)\mathrm{}$ muonic x-ray spectra for nine deformed even-even nuclei: ${}_{}{}^{150}{}_{}{}^{}\mathrm{Nd}$, ${}_{}{}^{152}{}_{}{}^{}\mathrm{Sm}$, ${}_{}{}^{162}{}_{}{}^{}\mathrm{Dy}$, ${}_{}{}^{164}{}_{}{}^{}\mathrm{Dy}$, ${}_{}{}^{168}{}_{}{}^{}\mathrm{Er}$, ${}_{}{}^{170}{}_{}{}^{}\mathrm{Er}$, ${}_{}{}^{182}{}_{}{}^{}\mathrm{W}$, ${}_{}{}^{184}{}_{}{}^{}\mathrm{W}$, and ${}_{}{}^{186}{}_{}{}^{}\mathrm{W}$. From these measurements, parameters describing the nuclear charge distribution have been determined. Nuclear-polarization corrections have been included in the analysis. The accuracy of the determination of the parameters of the nuclear charge distribution is limited by theoretical rather than experimental uncertainties. Isotope shifts have been determined and compared with optical and electronic x-ray results.

Isotope shifts in the muonic spectra of ${}_{20}{}^{40}{}_{}{}^{}\mathrm{Ca}$, ${}_{}{}^{44}{}_{}{}^{}\mathrm{Ca}$; ${}_{24}{}^{50}{}_{}{}^{}\mathrm{Cr}$, ${}_{}{}^{52}{}_{}{}^{}\mathrm{Cr}$, ${}_{}{}^{53}{}_{}{}^{}\mathrm{Cr}$, ${}_{}{}^{54}{}_{}{}^{}\mathrm{Cr}$; ${}_{29}{}^{63}{}_{}{}^{}\mathrm{Cu}$, ${}_{}{}^{65}{}_{}{}^{}\mathrm{Cu}$; ${}_{42}{}^{92}{}_{}{}^{}\mathrm{Mo}$, ${}_{}{}^{95}{}_{}{}^{}\mathrm{Mo}$, ${}_{}{}^{96}{}_{}{}^{}\mathrm{Mo}$, ${}_{}{}^{97}{}_{}{}^{}\mathrm{Mo}$; ${}_{50}{}^{116}{}_{}{}^{}\mathrm{Sn}$, ${}_{}{}^{117}{}_{}{}^{}\mathrm{Sn}$, ${}_{}{}^{118}{}_{}{}^{}\mathrm{Sn}$, ${}_{}{}^{119}{}_{}{}^{}\mathrm{Sn}$, ${}_{}{}^{120}{}_{}{}^{}\mathrm{Sn}$, ${}_{}{}^{122}{}_{}{}^{}\mathrm{Sn}$, ${}_{}{}^{124}{}_{}{}^{}\mathrm{Sn}$; ${}_{60}{}^{142}{}_{}{}^{}\mathrm{Nd}$, ${}_{}{}^{143}{}_{}{}^{}\mathrm{Nd}$, ${}_{}{}^{144}{}_{}{}^{}\mathrm{Nd}$, ${}_{}{}^{145}{}_{}{}^{}\mathrm{Nd}$, ${}_{}{}^{146}{}_{}{}^{}\mathrm{Nd}$, ${}_{}{}^{148}{}_{}{}^{}\mathrm{Nd}$, and ${}_{}{}^{150}{}_{}{}^{}\mathrm{Nd}$ have been measured using a stable high-resolution Ge(Li) spectrometer system. The results are compared with values calculated for assumed nuclear charge distributions. In the case of the Nd isotopes, the half-density radius and the skin thickness have been determined from the measured $K$ and $L$ x-ray energies. An interesting shell-closing effect has been observed among the Cr isotopes. The muonic isotope shifts have been used to extract specific-mass shifts from optical measurements. We find that, even in Nd, these specific-mass shifts are very large, and not at all negligible in the analysis of optical results. The isotope shifts in Sn follow favorably the theoretically predicted general trend. The great reduction of the isotope shift between ${}_{}{}^{122-124}{}_{}{}^{}\mathrm{Sn}$ as reported in an optical investigation was not found in the muonic case. Lastly, a comparison has been made between the muonic results and recent electronic x-ray measurements. These were found to be in reasonable agreement.

A method for measuring neutron-charged-particle coincidences from the 14.4-MeV neutron-induced reaction has been developed. The $n+d\to p+n+n$ reaction has been studied by the coincidence detection of the outgoing proton and neutron. The cross section has been measured as a function of five independent kinematic variables. A contribution of neutron-proton quasifree scattering has been observed. The cross section for ${\ominus }_n={\ominus }_p=30\mathrm{}°$ is found to be $\sigma =37.5\mathrm{}\pm 5.8$ mb/${\mathrm{sr}}^2$. This result is in fair agreement with the data for proton-proton quasifree scattering from the $p+d\to p+p+n$ reaction. The possibility of obtaining a proper $a_{\mathrm{nn}}$ value is discussed.

Proton recoil spectra from $n-p$ elastic scattering were measured with a counter telescope for an incident neutron energy of 24.0 MeV at mean lab proton recoil angles of 8°, 17°, 31°, and 45°, corresponding to c.m. neutron scattering angles of 164°, 146°, 118°, and 89°. The ratio $\frac{\sigma \left(164\mathrm{}°\right)}{\sigma \left(89\mathrm{}°\right)}$ was 1.134±0.016, where the error quoted is based on counting statistics. In order to obtain a differential cross section, the c.m. relative angular distribution was normalized to a total cross section of 397.2 mb using an $A(1+B{cos}^2\theta )$ fit. This gave $A=30.1\mathrm{}\pm 0.3$ mb/sr and $B=0.146\mathrm{}\pm 0.017$.

The activation cross sections for 18 ($n, p$), ($n, \alpha$), and ($n, 2n$) reactions have been measured with 14.8-MeV neutrons. The radioactivity measurements were carried out with a Ge(Li) detector. The cross sections measured, in millibarns, are ${}_{}{}^{27}{}_{}{}^{}\mathrm{Al}(n, p){}_{}{}^{27}{}_{}{}^{}\mathrm{Mg}$, 73±5; ${}_{}{}^{85}{}_{}{}^{}\mathrm{Rb}(n, 2n){}_{}{}^{84m}{}_{}{}^{}\mathrm{Rb}$, 714±50; ${}_{}{}^{85}{}_{}{}^{}\mathrm{Rb}(n, 2n){}_{}{}^{84g}{}_{}{}^{}\mathrm{Rb}$, 621±75; ${}_{}{}^{85}{}_{}{}^{}\mathrm{Rb}(n, p){}_{}{}^{85m}{}_{}{}^{}\mathrm{Kr}$, 6±1; ${}_{}{}^{87}{}_{}{}^{}\mathrm{Rb}(n, 2n){}_{}{}^{86m}{}_{}{}^{}\mathrm{Rb}$, 584±40; ${}_{}{}^{87}{}_{}{}^{}\mathrm{Rb}(n, 2n){}_{}{}^{86g}{}_{}{}^{}\mathrm{Rb}$, 833±60; ${}_{}{}^{87}{}_{}{}^{}\mathrm{Rb}(n, p){}_{}{}^{87}{}_{}{}^{}\mathrm{Kr}$, 7±1; ${}_{}{}^{84}{}_{}{}^{}\mathrm{Sr}(n, 2n){}_{}{}^{83}{}_{}{}^{}\mathrm{Sr}$, 395±75; ${}_{}{}^{86}{}_{}{}^{}\mathrm{Sr}(n, 2n){}_{}{}^{85m}{}_{}{}^{}\mathrm{Sr}$, 360±30; ${}_{}{}^{86}{}_{}{}^{}\mathrm{Sr}(n, p){}_{}{}^{86m}{}_{}{}^{}\mathrm{Rb}$, 9±1; ${}_{}{}^{88}{}_{}{}^{}\mathrm{Sr}(n, 2n){}_{}{}^{87m}{}_{}{}^{}\mathrm{Sr}$, 344±30; ${}_{}{}^{88}{}_{}{}^{}\mathrm{Sr}(n, p){}_{}{}^{88}{}_{}{}^{}\mathrm{Rb}$, 20±2; ${}_{}{}^{90}{}_{}{}^{}\mathrm{Zr}(n, 2n){}_{}{}^{89m}{}_{}{}^{}\mathrm{Zr}$, 143±15; ${}_{}{}^{90}{}_{}{}^{}\mathrm{Zr}(n, 2n){}_{}{}^{89g}{}_{}{}^{}\mathrm{Zr}$, 342±25; ${}_{}{}^{90}{}_{}{}^{}\mathrm{Zr}(n, p){}_{}{}^{90m}{}_{}{}^{}\mathrm{Y}$, 13±1; ${}_{}{}^{90}{}_{}{}^{}\mathrm{Zr}(n, \alpha ){}_{}{}^{87m}{}_{}{}^{}\mathrm{Sr}$, 4.6±0.5; ${}_{}{}^{93}{}_{}{}^{}\mathrm{Nb}(n, 2n){}_{}{}^{92m}{}_{}{}^{}\mathrm{Nb}$, 455±25; and ${}_{}{}^{93}{}_{}{}^{}\mathrm{Nb}(n, \alpha ){}_{}{}^{90m}{}_{}{}^{}\mathrm{Y}$, 5.8±0.5. The measured cross sectons are compared with those calculated by evaporation theory. The ($n, 2n$) measured cross sections agree well with the calculated values but the agreement between calculated and measured values for ($n, p$) reactions is poor.