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Experimental studies and theoretical calculations of photonuclear reactions on a natural mixture of palladium isotopes have been performed. The yields of photonuclear reactions on a natural mixture of Pd isotopes were measured for bremsstrahlung $$\gamma$$ radiation with a maximum energy of 55 MeV. The results are compared with calculations using the combined model of photonuclear reactions.

Experimental investigations and theoretical calculations were performed for the photoneutron reactions on the light palladium isotopes $${}^{102}\textrm{Pd}$$ and $${}^{104}\textrm{Pd}$$ . A target from a natural mixture palladium isotopes was irradiated with bremsstrahlung gamma rays generated at a racetrack microtron accelerating electrons to an energy of $$55$$ MeV (RTM-55). The absolute yields of the photoneutron reactions occurring on the isotopes $${}^{102}\textrm{Pd}$$ and $${}^{104}\textrm{Pd}$$ and leading to the emission of up to three neutrons were determined. The experimental results obtained in this way are compared with their counterparts calculated by means of the TALYS code and with evaluated cross sections.

The 110Pd(n,2n)109Pd, 102Pd(n,2n)101Pd, 105Pd(n,p)105Rh and 106Pd(n,p)106mRh reaction cross sections have been measured with respect to the 197Au(n,2n)196Au monitor reaction at the neutron energy of 14.54 ± 0.24 MeV by using the method of activation and off-line γ-ray spectrometry. The mono-energetic neutron beam was generated from the D–T reaction. The uncertainties in the various basic nuclear parameters in the measured reactions and their correlations were estimated by using covariance analysis. The present data were compared with the EXFOR based literature data, evaluated data of various libraries available in national nuclear data center and with the calculated values from TALYS-1.9 code.

Funding Information: Financial support by CMEco (Grant # 7405/31/2016) and SYMMET (Grant # 3891/31/2018) programs of Business Finland are gratefully acknowledged. Additional funding from the Alfred Kordelin Foundation, Finnish Cultural Foundation as well as the Emil Aaltonen Foundation (KA), and the Finnish Steel and Metals Producers’ Fund (LK) is also appreciated. The EPMA measurements were carried out by Mr. Lassi Pakkanen of the Geological Survey of Finland. This study utilized the Academy of Finland’s RawMatTERS Finland Infrastructure (RAMI) housed at Aalto University, GTK and VTT. Publisher Copyright: © 2021, The Author(s). Copyright: Copyright 2021 Elsevier B.V., All rights reserved. Dissolution and solubility of palladium in iron silicate melts saturated with alumina–iron spinel at 1300°C has been measured using an equilibration-drop quenching technique combined with electron probe microanalysis and laser ablation–inductive coupled plasma–mass spectrometry analysis from polished sections. Composition of the resulting Fe-Pd alloy allowed estimation of the activity of palladium at different oxygen partial pressures, and, thus, the solubilities of palladium in the studied slags in conditions typical of copper and nickel smelting as well as slag cleaning at pO2=10-5 to 10-10 atm. The mechanism of palladium dissolution in the studied iron silicate slags was oxidation by formation of the monovalent oxide species PdO0.5 over the entire oxygen activity range of this study. Testing the applicability of the various palladium isotopes for quantitative analyses of Pd in these types of matrices resulted in a good fit of measured concentrations of 104Pd and 105Pd with interference-corrected 106Pd and 108Pd.

With the proton number just below the magic number Z = 50, the palladium isotopes are known to exhibit rich nuclear structure phenomena. Inspired by the extensive experimental as well as theoretical structural investigations of Pd isotopes, we have performed the detailed study of band structures of 108–118Pd isotopes using triaxial projected shell model approach employing the multi-quasiparticle configuration space. As the mass region A ~ 110 depicts well-developed yrast, γ- and 2γ-bands, the present work demonstrates the reliable description of these bands by performing exact three-dimensional angular-momentum projection technique. The results obtained are also consistent with the global predictions of non-axial shapes for these isotopes. Besides this, the present study predicts the involvement of 2-quasiparticle neutron bands in describing various structural properties of these isotopes up to high spin states and has also achieved an excellent agreement of theoretical results with the known experimental data.

We report measurements of the isotope shift of the mass 104, 105, 106, 108, and 110 stable palladium isotopes for transitions from the metastable state $4{d}^{9}{(}^{2}{D}_{5/2})5s,{\phantom{\rule{0.16em}{0ex}}}^{2}{[5/2]}_{3}\ensuremath{\rightarrow}4{d}^{9}{(}^{2}{D}_{5/2})5p,{\phantom{\rule{0.16em}{0ex}}}^{2}{[7/2]}_{4}^{o}$ at 340 nm, and $4{d}^{9}{(}^{2}{D}_{5/2})5s,{\phantom{\rule{0.16em}{0ex}}}^{2}{[5/2]}_{3}\ensuremath{\rightarrow}4{d}^{9}{(}^{2}{D}_{5/2})5p,{\phantom{\rule{0.16em}{0ex}}}^{2}{[3/2]}_{2}^{o}$ at 363 nm. For $^{105}\mathrm{Pd}$, we determine the hyperfine structure of both transitions. The measurements were performed by saturation absorption spectroscopy in a custom-built hollow cathode lamp and will serve as a reference for collinear laser spectroscopy of short-lived neutron-rich palladium isotopes. We also report on the observation of a population inversion for the 363-nm transition under certain discharge conditions.

Deuteron-induced nuclear reactions for the generation of 103Pd were investigated using the stacked-foil activation technique on rhodium targets at deuteron energies up to Ed=33MeV. The excitation functions of the reactions 103Rh(d,xn)101,103Pd, 103Rh(d,x)100g,cum,101m,g,102m,gRh and 103Rh(d,2p)103Ru have been measured, and the Thick-Target Yield for 103Pd has been calculated.

Collinear laser spectroscopy on stable palladium isotopes was performed at the IGISOL facility in Jyväskylä in preparation for an experiment on its neutron-rich isotopes. Five transitions from different initial atomic states were tested, with the goal of finding the most spectroscopically efficient. The observed intensities afforded a comparison with atomic-level population predictions based on charge-exchange calculations. For some transitions hyperfine parameters of 105Pd were measured, which were found to be in good agreement with literature values. A King plot analysis was performed using the measured isotope shifts and known charge radii from literature to determine the atomic field and mass shift factors.

This paper presents a new method for high precision Pd isotope analyses in iron meteorites. First, Pd is separated from the sample matrix by a novel two-stage anion exchange procedure after which isotopic measurements are carried out using MC-ICP-MS. Analyses of doped standard solutions show that isobaric interference from Ru and Cd can be adequately corrected for Ru/Pd < 0.0005 and Cd/Pd < 0.025. This is frequently achieved using the presented separation method. The purified Pd fraction after ion exchange chromatography is also sufficiently devoid of Ni (Ni/Pd < 0.04), Zr (Zr/Pd < 0.0002) and Zn (Zn/Pd < 0.06) for precise and accurate measurements because these elements produce molecular interference on the masses of the Pd isotopes. An external reproducibility of 1.29 for e102Pd, 0.22 for e104Pd, 0.11 for e106Pd, and 0.27 for e110Pd is calculated based on the repeated analyses of five independently processed aliquots of the IAB iron meteorite Toluca. The method was verified by the analysis of three metals from IVB iron meteorites and the results show excellent agreement with previous data. The new method enables accurate analysis of all Pd isotopes, and in particular 102Pd, which is of major interest for cosmochemical applications.

In this study, the Palladium nuclei have been studied by interacting boson fermion model for even-odd nuclei. The isotopes under study have proton number 46 and neutron numbers 63-67. The calculations involved the eigenstates and reduce electric probability. The calculations show that the energy levels are reasonable with experimental data. The B(E2) values compared with those of experimental and are in good agreements. All calculations compared with experimental and give more data for reader.

Arc reactor is the design for compact fusion reactor. In this paper mechanism of an Arc Reactor is discussed which is a multi-isotope radio-decay cell that can be created using Low Energy Nuclear Reactor (LENR) technology which is a low-radiation fusion reactor. Here, Palladium isotope is used as a core and it generates significant amount of power.It also introduces a new portable method to generate power without generating too much heat and heavy radiation.

We present a novel two-step even–odd mass isotope selective excitation and ionization scheme, potentially applicable in resource recycling and management of palladium occurring in high-level nuclear waste. In contrast to the conventional three-step selective ionization process, the two-step scheme utilizes transition selection rules to an autoionizing Rydberg state, rather than to an intermediate state, resulting in an increase in efficiency of over an order of magnitude while retaining excellent selectivity of >99.7%. The reduction in the number of excitation lasers required allows several technical simplifications and reduces costs should the process be developed for large-scale resource recycling operations.

Energy levels and B(E2) transitions for palladium isotopes with proton number Z=46 and neutron numbers (n) between 57 and 67 have been calculated through the interacting boson-fermion model. The set of parameters used in this calculation is the best approximation that has been carried out so far. Good agreement was found from comparison between the calculated energy levels and the transition probabilities B(E2) with those of experimental.

It has been suggested that modern dose calculation algorithms should be able to report absorbed dose both as dose to the local medium, D-m,D-m, and as dose to a water cavity embedded in the medium, D-w,D-m, using conversion factors from cavity theory. Assuming that the cell nucleus with its DNA content is the most important target for biological response, the aim of this study is to investigate, by means of Monte Carlo (MC) simulations, the relationship of the dose to a cell nucleus in a medium, D-n,D-m, to D-m,D-m and D-w,D-m, for different combinations of cell nucleus compositions and tissue media for different photon energies used in brachytherapy. As D-n,D-m is very impractical to calculate directly for routine treatment planning, while D-m,D-m and D-w,D-m are much easier to obtain, the questions arise which one of these quantities is the best surrogate for D-n,D-m and which cavity theory assumptions should one use for its estimate. The Geant4.9.4 MC code was used to calculate D-m,D-m, D-w,D-m and D-n,D-m for photon energies from 20 (representing the lower energy end of brachytherapy for Pd-103 or I-125) to 300 keV (close to the mean energy of Ir-192) and for the tissue media adipose, breast, prostate and muscle. To simulate the cell and its nucleus, concentric spherical cavities were placed inside a cubic phantom (10 x 10 x 10 mm(3)). The diameter of the simulated nuclei was set to 14 mu m. For each tissue medium, three different setups were simulated; (a) D-n,D-m was calculated with nuclei embedded in tissues (MC-D-n,D-m). Four different published elemental compositions of cell nuclei were used. (b) D-w,D-m was calculated with MC (MC-D-w,D-m) and compared with large cavity theory calculated D-w,D-m (LCT-D-w,D-m), and small cavity theory calculated D-w,D-m (SCT-D-w,D-m). (c) D-m,D-m was calculated with MC (MC-D-m,D-m). MC-D-w,D-m is a good substitute for MC-D-n,D-m for all photon energies and for all simulated nucleus compositions and tissue types. SCT-D-w,D-m can be used for most energies in brachytherapy, while LCT-D-w,D-m should only be considered for source spectra well below 50 keV, since contributions to the absorbed dose inside the nucleus to a large degree stem from electrons released in the surrounding medium. MC-D-m,D-m is not an appropriate substitute for MC-D-n,D-m for the lowest photon energies for adipose and breast tissues. The ratio of MC-D-m,D-m to MC-D-n,D-m for adipose and breast tissue deviates from unity by 34% and 15% respectively for the lowest photon energy (20 keV), whereas the ratio is close to unity for higher energies. For prostate and muscle tissue MC-D-m,D-m is a good substitute for MC-D-n,D-m. However, for all photon energies and tissue types the nucleus composition with the highest hydrogen content behaves differently than other compositions. Elemental compositions of the tissue and nuclei affect considerably the absorbed dose to the cell nuclei for brachytherapy sources, in particular those at the low-energy end of the spectrum. Thus, there is a need for more accurate data for the elemental compositions of tumours and healthy cells. For the nucleus compositions and tissue types investigated, MC-D-w,D-m is a good substitute to MC-D-n,D-m for all simulated photon energies. Whether other studied surrogates are good approximations to MC-D-n,D-m depends on the target size, target composition, composition of the surrounding tissue and photon energy.

We review structure data obtained by decay spectroscopy of neutron-rich nuclei of mass close to 100. Emphasis is put on the contribution of experiments at IGISOL in the nineties. They confirmed the earlier postulated shape coexistence in the fast shape-transition region between N = 58 (spherical ground states and low collectivity) and N = 60 (strong axial deformation). A detailed spectroscopic study of the A = 99 chain established the upper-Z limit of the N = 56 shell closure region with 99Nb, owing to striking similarities with 97Y. A consequence of the N = 56 closure is that the s1/2 odd-neutron becomes the ground state of the most neutron-rich N = 57 isotones, starting with 99Mo, instead of the degenerated d5/2 and g7/2 subshells familiar in the tin region. Consequences on the change of spin on astrophysical r-process calculations are briefly discussed. Finally, we say a few words about neutron-rich rhodium and palladium isotopes near the neutron midshell where regular and intruder states coexist very close to each other.

Wombourne, West Midlands, UK Email: jwarblaster@yahoo.co.uk This review looks at the discovery and the discoverers of the thirty-eight known ruthenium isotopes with mass numbers from 87 to 124 found between 1931 and 2010. This is the sixth and fi nal review on the circumstances surrounding the discoveries of the isotopes of the six platinum group elements. The fi rst review on platinum isotopes was published in this Journal in October 2000 (1), the second on iridium isotopes in October 2003 (2), the third on osmium isotopes in October 2004 (3), the fourth on palladium isotopes in April 2006 (4) and the fi fth on rhodium isotopes in April 2011 (5). An update on the new isotopes of palladium, osmium, iridium and platinum discovered since the previous reviews in this series is also included.

Time Differential Perturbed Angular Correlation measurements were performed in intrinsic germanium with the 100Pd/100Rh probe. The probe was produced via 92Zr(12C, 4n)100Pd and recoil-implanted into samples. Parallel measurements with the 111In/111Cd probe confirmed the quality of the germanium studied. The measurements with the 100Pd/100Rh probe show a modulation pattern in the ratio function with a quadrupole interaction frequency of 8.3(2) Mrad/s. The pattern depends on sample orientation and it is most pronounced after annealing at 500°C. After annealing at 700°C the effect vanishes due to strong damping of the ratio function. The pattern may be caused, similar to what has been observed for highly doped n-type silicon, by the pairing of the Pd-atom with a vacancy located in the direction. The disappearance of the pattern would indicate the dissociation of this pair. Pair formation and dissociation may be relevant to palladium-induced-crystallization processing of germanium.

The new facility of the RIKEN RI Beam Factory (RIBF) is dedicated to provide beams of unstable nuclei very far from the stability valley. It started operation at the end of 2006 after 10 years construction. Three newly-built cyclotrons boost the energy up to 345 MeV/nucleon for various heavy-ion beams accelerated by pre-existed accelerators, a linac (RILAC) and a ring cyclotron (RRC), which have been operated in 20 years. The first experiment in the year 2007, production of new neutron-rich palladium isotopes, was followed by the first experiment of secondary reactions at the end of 2008. The capability in producing nuclei far from the stability is exceeding the one of any other facilities in the world, and will reach the level where about 1000 unknown isotopes can be created. Several new experimental installations are planned or being constructed.

Results of the first direct observation of the true ternary fission of 234Pa* nucleus are presented. The yield of the effect depending on the experimental geometry is about 10−5/binary fission. Mass of the lightest fragment in the triplet lies mainly in the range of 20–40 a.m.u. An intimate connection between the effect and known cluster decay as well as conventional binary fission is briefly discussed.

Experimental information is presented from the neutron rich 103Zr to the neutron deficient 103Sn. At the neutron rich side, new information on the β− decay of 103Zr (1.3 s), 103Nb (1.5 s) and 103Mo (67.5 s) is presented. From (n,γ) studies, very elaborate level and γ information in 103Ru was obtained. The excited states of 103Ru have been studied via 102Ru(d,p) and 104Ru(d,t) experiments. The β− decay of 103Ru (39.26 d) was studied extensively while the 103Ag e decay was also reinvestigated. Excited states of 103Pd were studied via 104Pd(d,t),(3He,α). The 103Cd e decay (7.3 min) has been investigated by several groups. (HI,xnypγ) reactions were used in the study of the high spin states in 103Ag. For the first time, experimental information is shown for the decay of 103In (65 s). Theoretical studies on different properties of A=103 nuclei are reported in the adopted levels tables.

Experimental data on ground- and excited-state properties for all known nuclei with mass number A = 96 have been compiled and evaluated. States populated in radioactive decay, as well as in nuclear reactions, have been considered. For these nuclei, level and decay schemes, as well as tables of nuclear properties, are presented. This work supersedes the 1993 evaluation by L.K. Peker (1993Pe02). In summary, three isomers were identified in {sup 96}Ag (2003Ba39,1997Gr02), even though the relative energies were not established. In {sup 96}Ru a nuclear fluorescence experiment (2005Li59) determined the spin, branching ratios and transition strengths of dipole excitations; high-spin level properties were reported by 2000Kh02 and 2002Kl07. High spin levels in {sup 96}Tc were studied in 2001Bu19. For {sup 96}Mo, there are new high-spin data (2000Ch42), as well as low-spin levels produced in (n,n{sup '}{gamma}) (2007Le05) and ({gamma},{gamma}{sup '}) (2004Fr30). High spin data (2005Pa48) were obtained for {sup 96}Zr using heavy-ion induced fission. For {sup 96}Sr, new levels were deduced using alpha-induced (2005Pa48) and spontaneous fission. The decay of a (10-) isomer in {sup 96}Rb was studied by 2005Pi13. Several new mass measurements for neutron rich nuclides have been published, which were used to obtain Q-values and separation energies.

The radioactive decay of the isotopes 254-256Lr and their daughter products was investigated by means of α , prompt α -γ and delayed conversion electron-γ coincidence spectroscopy. The isotopes were produced using the reaction 48Ca + 209Bi .

Dependence of isomeric ratios on maximum photon energy in the reactions 110Pd(γ, n)109m, gPd and 113In(γ, n)112m, gIn is studied in the energy region of bremsstrahlung 9–18 MeV with the step ΔE = 0.5 MeV. Cross sections of population of the metastable state for 109Pd and 112In in (γ, n) reactions were first obtained in the energy region under study. The obtained results are compared with the results of the calculation in the framework of the cascade-evaporation model.

Monte Carlo (MC) simulations were performed to estimate brachytherapy dose distributions for Collaborative Ocular Melanoma Study (COMS) eye plaques. Brachytherapy seed models 200, 6711, and CS-1 Rev2 carrying 103Pd, 125I, and 131Cs radionuclides, respectively, were modeled and benchmarked against previously published values. Calculated dose rate constants MClambda were 0.684, 0.924, and 1.052 cGy h(-1) U(-1) (+/- 2.6%, k = 1 uncertainty) for models 200, 6711, and CS-1 Rev2, respectively. The seeds were distributed into 10, 12, 14, 16, 18, 20, and 22 mm-diameter COMS eye plaques. Simulations were performed in both heterogeneous and homogeneous environments, where the latter were in-water and the former included the silastic seed carrier insert and gold-alloy plaque. MC-based homogenous central axis dose distributions agreed within 2% +/- 1% (+/- 1 s.d.) to hand-calculated values. For heterogeneous simulations, notable photon attenuation was observed, with dose reduction at 5 mm of 19%, 11%, and 9% for 103Pd, 125I, and 131Cs, respectively. A depth-dependent correction factor was derived to correct homogenous central-axis dose distributions for plaque component heterogeneities, which were found to be significant at short radial distances.

The 1994 evaluation on mass A = 106 has been revised, taking into account all data available before May 2007. Detailed experimental information is presented from the neutron rich nucleus {sup 106}Y to the neutron deficient {sup 106}Te nucleus. All conversion coefficients have been calculated with BRICC.

In the present study, $B(E2; 2^{+}_{1}\rightarrow 0^{+}_{1})$ values have been measured in the 208,210Rn and 206Po nuclei through Coulomb excitation of re-accelerated radioactive beams in inverse kinematics at CERN-ISOLDE. These nuclei have been proposed to lie in, or at the boundary of the region where the seniority scheme should persist. However, contributions from collective excitations are likely to be present when moving away from the N=126 closed shell. Such an effect is confirmed by the observed increased collectivity of the $2^{+}_{1}\rightarrow 0^{+}_{1}$ transitions. Experimental results have been interpreted with the aid of theoretical studies carried out within the BCS-based QRPA framework.

We formulate a microscopic description of charge-changing excitations, including dynamical mixture of one- and two-phonon states. The present formalism generalizes our previous microscopic anharmonic vibrator approach (MAVA), designed to treat charge-conserving two- and four-quasiparticle degrees of freedom and their mixing. In the present formalism, the proton–neutron MAVA, pnMAVA, the main building blocks are the quasiparticle random-phase approximation (QRPA) phonons in the charge-conserving channels, and the proton–neutron QRPA (pnQRPA) phonons in the charge-changing channels. The QRPA and pnQRPA equations are directly used in deriving the equations of motion for two-phonon states. The beta-decay Gamow–Teller matrix elements, connecting the 1 + states of a double-odd nucleus with two-phonon 0 + and 2 + states of the neighboring double-even nucleus, contain contributions from the metric matrix and scattering terms of the beta-decay operator. The pnMAVA has been applied to predict β − -decay and β + -decay amplitudes for transitions feeding the one- and two-phonon states in the palladium isotopes 106,108Pd. A fair agreement with the data has been achieved.

Underlying characteristics in brachytherapy dosimetry parameters for medical radionuclides 137Cs, 125I, 192Ir, 103Pd, and 169Yb were examined using Monte Carlo methods. Sources were modeled as unencapsulated point or line sources in liquid water to negate variations due to materials and construction. Importance of phantom size, mode of radiation transport physics--i.e., photon transport only or coupled photon:electron transport, phantom material, volume averaging, and Monte Carlo tally type were studied. For noninfinite media, g(r) was found to degrade as r approached R, the phantom radius. MCNP5 results were in agreement with those published using GEANT4. Brachytherapy dosimetry parameters calculated using coupled photon:electron radiation transport simulations did not differ significantly from those using photon transport only. Dose distributions from low-energy photon-emitting radionuclides 125I and 103Pd were sensitive to phantom material by upto a factor of 1.4 and 2.0, respectively, between tissue-equivalent materials and water at r =9 cm. In comparison, high-energy photons from 137Cs, 192Ir, and 169Yb demonstrated +/- 5% differences in dose distributions between water and tissue substitutes at r=20 cm. Similarly, volume-averaging effects were found to be more significant for low-energy radionuclides. When modeling line sources with L < or = 0.5 cm, the two-dimensional anisotropy function was largely within +/- 0.5% of unity for 137Cs, 125I, and 192Ir. However, an energy and geometry effect was noted for 103Pd and 169Yb, with Pd-103F(0.5,0 degrees)=l.05 and yb-169F(0.5,0 degrees)=0.98 for L=0.5 cm. Simulations of monoenergetic photons for L=0.5 cm produced energy-dependent variations in F(r, theta) having a maximum value at 10 keV, minimum at 50 keV, and approximately 1.0 for higher-energy photons up to 750 keV. Both the F6 cell heating and *F4 track-length estimators were employed to determine brachytherapy dosimetry parameters. F6 was found to be necessary for g(r), while both tallies provided equivalent results for F(r, theta).

New half-lives for neutron-rich ruthenium, rhodium and palladium isotopes close to the r-process path along the N=82 closed shell have been measured at the National Superconducting Cyclotron Laboratory at Michigan State University. The studied isotopes are close to the critical A=118-126 mass region in the astrophysical r-process, where incorrect nuclear structure development towards the shell closure may have the most pronounced effect on the abundances of elements produced. Neutron-rich nuclei were produced by fragmentation of a 120-MeV per nucleon 136 Xe beam on Be and were separated by the A1900 fragment separator. The nuclei of interest were implanted into a double-sided Si strip detector at the center of the MSU β counting system. Charge states and fully- stripped isotopes were distinguished by a measurement of the total kinetic energy of each implant. Our measured half-lives will provide first clues on whether our understanding of nuclear structure evolution in this mass region is correct.

Angular distributions for the inelastic scattering of 13.0 MeV deuterons on 104;106;108;110Pd were measured with the Sao Paulo Pelletron-Enge-Spectrograph facility in the range of 12(0) < thetalab < 64(0). A Coulomb-Nuclear Interference analysis, employing the Distorted Wave Born Approximation with the Deformed Optical Model as transition potential, under well established global optical parameters, was applied to the first quadrupolar excitations. The values of C = / , the ratio of charge to isoscalar deformation lengths, and of ()² were extracted through the comparison of experimental and predicted cross section angular distributions. The ratios of reduced charge to isoscalar transition probabilities, B(EL) to B(ISL) respectively, are related to the square of the parameter C and were thus obtained with the advantage of scale uncertainties cancellation. For 104Pd, and preliminary for 108Pd, the respective values of C = 1.18(3) and C = 1.13(4) reveal an enhanced contribution of the protons relative to the neutrons to the excitation, while a smaller effect is found for 106Pd, C = 1.06(3) and for 110Pd, C = 1.07(3), in comparison with the value C = 1.00 expected for homogenous collective excitations.

The new data provided by recent experiments on 118Pd, a nucleus not previously investigated, and on the high-spin states of the yrast band in even $^{110\mbox{--}116}$ Pd isotopes have been analyzed in the framework of the IBA-2 model, extending a former study. A correct description of the properties of 118Pd has been obtained by using model parameters equal or very close to those of the neighbouring isotopes. The importance of mixed-symmetry components for a satisfactory description of the states of $J \geq 10$ in $^{110\mbox{--}118}$ Pd is pointed out.

Neutron-rich nuclei populated in spontaneous fission are providing new tests for microscopic models. The neutron-rich 104–108 Mo, 108–114 Ru and 112–116 Pd exibit a variety of rapidly changing collective band structures to high spins. The first evidence for chiral band doublets in any even-even nucleus are reported.

The effects of a significant decrease in the sputtering rate and of the symmetrical separation of the isotope pairs 108Pd-105Pd and 110Pd-104Pd at depths up to 500 A are experimentally detected in Pd specimens saturated with deuterium during electrolysis (i.e., having a high concentration of internal stresses). These effects are shown to be qualitatively explained using the concepts of isotope separation by centrifugation and diffusion with allowance for defects and mechanical stresses that appear in the near-surface Pd layer during deuterium penetration.

A brief review on laser separation of rare ytterbium and palladium isotopes by selective photoionisation is presented. The 168Yb isotope enrichment is performed using the optical scheme proposed by A.M. Prokhorov and co-workers in 1991. The kinetic model of selective photoionisation is described in detail and the production of highly enriched 168Yb isotopes in weight quantities is reported (up to 90 % — 95 % in a plasma, up to 62 % on a collector, and up to 45 % in a wash solution). The rate of production of enriched ytterbium achieves 5 — 10 mg h-1 (more that 1 g per month). The results of theoretical and experimental studies of selective photoionisation of palladium are also presented. A substantial enrichment of different palladium isotopes is achieved: 102Pd — up to 18 % (the natural content is 1 %), 104Pd — up to 70 % (11.4 %), and 105Pd — up to 60 % (22.33 %). The kinetics of selective ionisation of palladium is analysed using new experimental data on the fine structure and hyperfine splitting of the terms.

A scheme for isotope-selective ionisation of palladium is studied experimentally. A considerable enrichment by the 102Pd, 104Pd, and 105Pd isotopes is achieved. Based on experimental data, the estimate for the hyperfine and isotopic structures of the 4d95p 3P1 level is obtained according to which the requirements to laser radiation and the Doppler width of atomic lines providing a high photoionisation selectivity are determined. To obtain a highly enriched (above 50 %) 102Pd isotope, the spectral width of a laser line (after frequency doubling) should be 60 — 80 MHz, the laser frequency stability (before doubling) should be 20 — 40 MHz, and the width of atomic lines should not exceed 100 MHz.

Investigations of double beta decay processes to excited states of daughter nuclei were performed at the Modane underground laboratory (LSM, France, 4800 m w.e.) using the high sensitivity spectrometer OBELIX [1], which is a common activity of JINR Dubna, IEAP CTU in Prague and LSM. The spectrometer is based on the HPGe detector with the sensitive volume of 600 cm3 and relative efficiency of 160%. Investigation of resonant neutrino-less double electron capture of 106Cd was performed with ∼23.2 g of 106Cd (enrichment of 99.57%) during ∼17 days. The experiment with natural Ni (∼21.7 kg of mass) was also carried out during ∼47 days. The preliminary experimental limits for 0νEC/EC resonant decay to the excited states of 106Pd and different modes of β β decay 58Ni are presented.

Databases for production of 103Pd, 201T1 radioisotopes and medical radioisotopes of iodine are presented including about 50 excitation functions for the main production routes and for disturbing re...

It is proposed to use the Zeeman effect for increasing the selectivity of laser isotope separation. It is shown on the basis of the available spectroscopic data that the selectivity of laser separation of the palladium isotope 102Pd can be increased significantly by using the Zeeman effect.

The isotopes used for permanent prostate implants, 125 I and 103 Pd , provide about equivalent tumor control. The purpose of this study is to investigate how characteristic x rays may be used to raise the relative biological effectiveness (RBE) of an iodine seed at short distances to increase the differential effect between tumor and healthy tissue. Within the theoretical framework of microdosimetry, the GEANT4 Monte Carlo simulation toolkit has been used to calculate the RBE of experimental seed designs in which shell and core dimensions and composition were varied independently. A new seed model was also simulated based on the best results obtained. The RBE could be enhanced by increasing the shell thickness and for the range considered, optimum results were obtained by using gradually lower atomic number elements. For a practical 50–60 μm shell, molybdenum is the material of choice. The core diameter has little influence on RBE, but maximum effectiveness is obtained with yttrium or zirconium. These results were put together to design a Mo-shell and Y-core seed for which the RBE enhancement was at least 5–7 % (close to the source), which is higher than palladium. This enhanced RBE combined with the longer half-life of iodine could mean comparable tumor control and better protection to organs at risk than with current seeds. The RBE dependence on distance is an interesting feature that could benefit other applications such as ocular melanoma or coronary brachytherapy where a highly localized dose distribution is desired.

Activation cross-sections for 18 (n,2n) reactions producing short-lived nuclei with half-lives between 20 s and 38 min were measured in the energy range between 13.4 and 14.9 MeV by an activation method. The measured target isotopes were 14N, 31P, 54Fe, 63Cu, 79Br, 87Rb, 92Mo, 108Pd, 113In, 132Ba, 138Ba, 140Ce, 141Pr, 144Sm and 165Ho. Four cross-sections for 108Pd, 132Ba, 144Sm and 165Ho were obtained at six-point energies for the first time. The intense 14 MeV neutron source facility (OKTAVIAN) at Osaka University was used for irradiation. All cross-section values were relatively obtained on the basis of the standard cross-section of 27Al(n, α) 24Na reaction (ENDF/B-VI). To obtain reliable neutron activation cross-sections, careful attention was paid to neutron irradiation and induced activities measurement. The present results were compared with previous data and the evaluated data in JENDL-3.2, JENDL-Activation File and ENDF/B-VI. The previous data measured at multi-point energies show reasonable agreement with the present results in comparison with those at one-point energy. There are overestimations of the cross-section for 31P in JENDL-3.2 and ENDF/B-VI, and for 132Ba and 165Ho in JENDL-Activation File.

Experimental data showing generation of {sup 4}He from a Pd sheet-D{sub 2} gas system observed by E. Botta et al. are analyzed by the trapped neutron catalyzed fusion (TNCF) model. The proposed mechanism of {sup 4}He generation is not the direct d-d reaction but the reactions between the trapped neutron and a Pd isotope, n-{sub 46}{sup A}Pd reactions, with a supplemental assumption, decrease of threshold energies for (n,{alpha}) reactions of {sub 46}{sup A}Pd in solids. The arbitrary parameter n{sub n}, the density of the trapped neutron, of the model is determined to be {approx}10{sup 12} cm{sup -3}, which is consistent with values determined in analyses of data in various events in the cold fusion phenomenon.

The 1991 evaluation of A = 107 has been revised. Experimental information is presented for various A = 107 nuclides, from the neutron-rich 107 Nb to the neutron-deficient 107 Te. All data available before June 1999 have been considered.

A simple method is presented for the separation of no-carrier-added 111Ag from neutron irradiated natural palladium. The method is based on sorption of 111Ag in 0.01 M HCl on alumina. Palladium is removed by washing with 0.1 M HCl and the 111Ag is eluted with 4 M HCl. The overall yields of 111Ag are better than 85% with1 microg/ml palladium as an impurity. The whole procedure from dissolving the target to the final 111Ag solution takes about 2 h.

Cross sections for (n, p), (n, α ) and (n, 2n) reactions have been measured on palladium isotopes at 13.5–14.7 MeV using the activation technique. Data are reported for the following reactions: 102 Pd(n, p) 102 m Rh, 102 Pd(n, p) 102 g Rh, 105 Pd(n, p) 105 Rh, 106 Pd(n, p) 106 Rh; 106 Pd(n, α ) 103 Ru, 108 Pd(n, α ) 105 Ru; 102 Pd(n, 2n) 101 Pd and 110 Pd(n, 2n) 109 Pd.

The isotopes ${}^{68--74}\mathrm{Ni}$, of interest both for nuclear physics and astrophysics, have been produced in proton-induced fission of ${}^{238}\mathrm{U}$ and ionized in a laser ion guide coupled to an on-line mass separator. Their $\ensuremath{\beta}$ decay was studied by means of $\ensuremath{\beta}$- $\ensuremath{\gamma}$ and $\ensuremath{\gamma}$- $\ensuremath{\gamma}$ spectroscopy. Half-lives have been determined and production cross sections extracted. A partial level scheme is presented for ${}^{73}\mathrm{Cu}$ and additional levels for ${}^{71}\mathrm{Cu}$, providing evidence for a sharply lowered position of the $\ensuremath{\pi}{1f}_{5/2}$ orbital as occupancy of the $\ensuremath{\nu}{1g}_{9/2}$ state increases. The latter may have a clear impact on the predicted structure and decay properties of doubly magic ${}^{78}\mathrm{Ni}$.

Excited states in 113Pd, populated in β− decay of 113Rh and in spontaneous fission of 248Cm and 252Cf, have been studied by means of γ spectroscopy at the IGISOL facility of Jyvaskylä University and using large arrays of Ge detectors (Eurogam2 and Gammasphere, respectively). The position of the 11/2− yrast excitation in 113Pd, proposed recently at 166.1 keV by other authors, has been corrected to 98.9 keV. The decay of this level has been discussed to explain the observed transition intensities. The 7/2− member of the yrast, unique-parity configuration has been identified at 84.9 keV and a band on top of this level proposed. On top of the 1/2+, first excited state a band has been built and a new 3/2+ bandhead has been proposed at 151.9 keV. A possible oblate-shape origin of these low-energy bandsheads has been discussed. peerReviewed

The short-lived isomeric states in the T{sub Z}=1 nuclei, {sup 94m}Pd [T{sub 1/2}=0.6(1) {mu}s] and {sup 96m}Ag [T{sub 1/2}=0.7(2) {mu}s], were identified among the fragmentation products of the {sup 112}Sn (63A MeV) + {sup nat}Ni (93.5 mg/cm{sup 2}) reaction at GANIL. The separation and identification of the reaction products was done by means of the Alpha and LISE3 magnetic spectrometers combined with time-of-flight, energy-loss, and total kinetic energy measurements. Evidence for isomeric states in {sup 80}Y, {sup 98}Cd, and {sup 102}Sn was also obtained. {copyright} {ital 1997} {ital The American Physical Society}