Abstract: The effectiveness of therapeutically used iron compounds is related to their physical and chemical properties. Four different iron compounds used in oral, intravenous, and intramuscular therapy have been examined by X-ray powder diffraction, iron-57 Mossbauer spectroscopy, transmission electron microscopy, BET surface area measurement, potentiometric titration and studied through dissolution kinetics determinations using acid, reducing and chelating agents. All compounds are nanosized with particle diameters, as determined by X-ray diffraction, ranging from 1 to 4.1 nm. The superparamagnetic blocking temperatures, as determined by Mossbauer spectroscopy, indicate that the relative diameters of the aggregates range from 2.5 to 4.1 nm. Three of the iron compounds have an akaganeite-like structure, whereas one has a ferrihydrite-like structure. As powders the particles form large and dense aggregates which have a very low surface area on the order of 1 m2 g−1. There is evidence, however, that in a colloidal solution the surface area is increased by two to three orders of magnitude, presumably as a result of the break up of the aggregates. Iron release kinetics by acid, chelating and reducing agents reflect the high surface area, the size and crystallinity of the particles, and the presence of the protective carbohydrate layer coating the iron compound. Within a physiologically relevant time period, the iron release produced by acid or large chelating ligands is small. In contrast, iron is rapidly mobilized by small organic chelating agents, such as oxalate, or by chelate-forming reductants, such as thioglycolate.

Abstract: The Canadian Penning Trap (CPT) mass spectrometer is a device used for high-precision mass measurements on short-lived isotopes. It is located at the ATLAS superconducting heavy-ion linac facility where a novel injection system, the RF gas cooler, allows fast reaction products to be decelerated, thermalized and bunched for rapid and efficient injection into the CPT. The CPT spectrometer and its injection system will be described in detail and its unique capabilities with respect to its initial physics program, concentrating on isotopes around the N=Z line with particular emphasis on isotopes of interest to low-energy tests of the electroweak interaction and the rp-process, will be highlighted.

Abstract: HITRAP is a planned ion trap facility for capturing and cooling of highly charged ions produced at GSI in the heavy-ion complex of the UNILAC-SIS accelerators and the ESR storage ring. In this facility heavy highly charged ions up to uranium will be available as bare nuclei, hydrogenlike ions or few-electron systems at low temperatures. The trap for receiving and studying these ions is designed for operation at extremely high vacuum by cooling to cryogenic temperatures. The stored highly charged ions can be investigated in the trap itself or can be extracted from the trap at energies up to about 10 keV/q. The proposed physics experiments are collision studies with highly charged ions at well-defined low energies (eV/u), high-accuracy measurements to determine the g-factor of the electron bound in a hydrogen-like heavy ion and the atomic binding energies of few-electron systems, laser spectroscopy of HFS transitions and X-ray spectroscopy.

Abstract: Based on the use of a single ion, isolated at the center of a cryogenically cooled Penning trap, an environment is produced which makes this mass spectrometer remarkably free of systematic errors. The most notable developments in our quest for an ultra-high accuracy instrument were (a) the compensation of the trapping potential, (b) the discovery that motional sidebands could manipulate radial energies, (c) the use of multiply-charged ions that could improve signal-to-noise, and (d) the use of an ultra-stable superconducting magnet/cryostat system with drift <0.010 ppb/h. The dominant systematic errors are associated with radial electric fields caused by image charges in the trap electrodes and with the rf-electrical drive field used to determine the harmonic axial resonance. To illustrate the potential of this improved spectrometer, the four-fold improved measurement of the proton's mass and the eight-fold improved measurement of oxygen's atomic mass will be described.

Abstract: In a recent experiment performed at PSI, a peak in the time-of-flight distribution of pμ(1s) atoms could be identified with decay of ppμ* molecular ions situated below the 2s threshold, providing 900 eV of kinetic energy to the pμ atom. This finding may be interpreted in terms of the side path model which suggests that metastable muonic molecules may form with high probability in resonant collisions between muonic hydrogen in the 2s state and hydrogen molecules, e.g. $$p\mu (2s) + {\text{H}}_{\text{2}} \to [(pp\mu ^* )_{vJ}^{pq} - pee]_{vK} \to [(pp\mu ^* )_{v'J'}^{p'q'} - pe]^ + + e^ - .$$ The Coulombic decay of the Auger stabilised ppμ* molecular ion then leads to the formation of highly energetic pμ(1s) atoms. In the present paper calculations of resonant formation rates in pure hydrogen are presented and compared to the quenching rate of pμ(2s) atoms measured at low hydrogen density.

Abstract: Because of the high density of energy storage and the large cross section for its release, nuclear spin isomers have attracted considerable recent interest The triggering of induced gamma emission from them has encouraged efforts to develop intense sources of short-wavelength radiation One of the more interesting examples is the 16+ 4-qp isomer of 178Hf which stores 2445 MeV for a half-life of 31 years meaning that as a material, such isomeric 178Hf would store 13 GJ/g Recently, a sample containing 63×1014 nuclei of the isomer of 178Hf was irradiated with X-ray pulses derived from a device operated at 15 mA to produce bremsstrahlung radiation with end point energies set to values between 60 and 90 keV Emission of gamma radiation from the sample was increased by 1–2% above the quiescent value of spontaneous emission Such an accelerated decay of the 178Hf isomer is consistent with an integrated cross section of 22×10−22 cm2 keV if the resonant absorption of the X-rays takes place below 20 keV as indicated by the use of selective absorbing filters in the irradiating beam The work reported here describes the current experimental focus and results recently obtained with the use of coincident detection of emitted gamma photons by several detectors

Abstract: The electronic structure of II–VI and III–V compound-based diluted magnetic semiconductors is calculated based on the local density approximation (LDA) using the Korringa–Kohn–Rostoker method combined with the coherent potential approximation. The magnetism of 3d transition-metal-atom-doped ZnO, ZnS, ZnSe, ZnTe, GaN, GaAs is investigated from first-principles. It is suggested that the double exchange mechanism stabilizes the ferromagnetism in these DMSs. In order to obtain microscopic information on the electronic structure of transition-metal-impurities in semiconductors, the hyperfine field of respective impurities in each host material is calculated. It is found that the agreement with the experimental values is not good, probably because the LDA is not sufficient to describe the core states of transition metals. However, it is suggested that the hyperfine fields clearly reflect the local magnetic moments for 3d impurities.

Abstract: During 25 years pioneering μCF experiments were performed at PSI. After initial study of the Wolfenstein–Gershtein effect in H/D, an intense research program on dμd fusion led to the early discovery of resonant dμd formation at low temperature and to the first direct observation of μd spin flip. With the Gatchina ionisation chamber absolute precisions of ∼1% on the determination of dμd formation and spin flip rates were recently obtained in good agreement with the theory.

Abstract: Six crystalline ferrates(VI): K3Na(FeO4)2, K2FeO4, Rb2FeO4, Cs2FeO4, K2Sr(FeO4)2 and BaFeO4, were studied by Mossbauer spectroscopy. Room-temperature spectra of potassium, rubidium and cesium ferrates are single lines, but spectra of barium, potassium–strontium and potassium–sodium ferrates show a presence of quadrupole interactions. Most of these salts display an antiferromagnetic transition with a Neel temperature within 2 to 8 K range.

Abstract: Measurement of thermal and elastic properties of materials, like phonon density of states, specific heat or speed of sound, by a new X-ray scattering technique is presented. Inelastic nuclear resonant scattering of X-rays produced from new electron storage rings, coupled with advances in high-energy-resolution crystal optics and fast detectors has enabled the development of a new method of analyzing the energy loss in a scattering process with a resolution of 107 or better in the X-ray region of 6–30 keV. Some unique aspects like element (isotope) selectivity, the amount of material needed for analysis (nanograms) and physical size that X-rays can be focused (5 micrometer or better) favors this approach over more established techniques of neutron scattering, Mossbauer, and Raman spectroscopy. Applications to several unique cases (e.g., multilayers and high pressure) are discussed.

Abstract: Penning trap mass spectrometry has reached a state that allows its application to very short-lived nuclides available from various sources of radioactive beams. Mass values with outstanding accuracy are achieved even far from stability. This paper illustrates the state of the art by summarizing the status of the ISOLTRAP experiment at ISOLDE/CERN. Furthermore, results of mass measurements on unstable rare earth isotopes will be given.

Abstract: Mass measurements of the N = Z nuclei 80Zr, 76Sr, 68Se were performed for the first time and a new measurement was obtained for 80Y, using the second cyclotron CSS2 of GANIL as a high-resolution spectrometer. Ions around N = Z were produced by fusion-evaporation in the inverse 58Ni (4.32 MeV A) + 24Mg and 12C reactions. New masses were measured by a time-of-flight method, with a precision of 2 · 10-6, by using well-known masses as references. Study of the double binding energy difference δV np is then performed leading to a strong N = Z Wigner effect around N = Z = 40. Knowledge of new masses in this region also plays a crucial role in the modelling of the astrophysical rp process.

Abstract: Since EXAT98 at Ascona, significant progress has been marked for experimental investigations of the fundamental understanding of muon catalyzed fusion (μCF) phenomena in D–T, D2 and other hydrogen systems. Future progress in the μCF studies is now guaranteed due to the successful launching of advanced accelerator projects such as JAERI-KEK Joint Proton Accelerator project and RI Beam Factory project at RIKEN. Also, the start of the next-phase thermal nuclear fusion project of ITER becomes promising so that some future contributions from ITER to μCF or vice-versa can be expected for various physical or technological aspects of fusion research. The future progress of μCF studies will also be promoted because of the growth of various other scientific research using muons. The essence of all these subjects is reviewed.

Abstract: Mass selective buffer gas cooling is a technique used for ions that are stored in a Penning trap. The technique can be applied to all elements and the mass resolving power achieved has proven to be sufficient to resolve isobars. When not only a few but 106 and more ions are stored at the same time, space charge starts to play a dominant role for the spatial distribution. In addition, the observed cyclotron frequency is shifted. This work investigates these effects by numerical calculations.

Abstract: An ion catcher as presented in this contribution is able to create cooled and very clean singly-charged ion pulses out of a ‘hot’ beam within a very short period of time. Precision measurements on shortlived radioactive nuclides become possible. This contribution describes experiments with a 252Cf fission source at the ‘gas-cooler’ at ATLAS (Argonne Tandem Linac Accelerating System) at the Argonne National Laboratories (ANL), Argonne, USA [1]. The system consists of a gas-cell to stop and thermalize the ions, two extraction radio frequency quadrupole structures (RFQ) to separate the ions from the buffer gas and a buncher RFQ to cool and accumulate the ions. The system and its performance is investigated with two independent measurements. The transported activity was measured to determine the efficiency of the system and time of flight measurements (TOF) were performed to determine the transported masses with respect to the transported activity.

Abstract: Projectile fragments of a 209Bi beam were separated in flight with the fragment separator FRS and injected into the experimental storage ring ESR. In the ESR a beam containing up to about 100 different isotopes was cooled to a relative velocity spread of δυ/υ = 10 by means of the electron cooler. The image currents of the ions induced in a Schottky pick-up probe at each turn were recorded. A subsequent Fast Fourier Transformation of these signals yields the revolution frequencies of the different isotopes stored in the ESR. Unknown masses of more than 150 neutron-deficient nuclides in the element range of 52 ≤ Z ≤ 85 have been measured directly by Schottky Mass Spectrometry and in addition more than 60 new masses have been obtained from α-decay chains. These new mass data allow the location of the one-proton dripline and the prediction of the two-proton dripline for heavy nuclides. The experimental masses are compared with different theoretical predictions.

Abstract: Single-phase amorphous Fe52Nb48 and Fe36Nb64 alloys were synthesized during mechanical alloying (MA) processes. X-ray diffraction and Mossbauer spectroscopy were used to study the structure and hyperfine interactions of the milling products. Some differences in the formation mechanism of a single-phase amorphous alloy were observed between Fe52Nb48 and Fe36Nb64. However, in both cases the final product of MA processes were amorphous alloys in paramagnetic state.

Abstract: We have used REXTRAP at ISOLDE to test the feasibility of in-trap electron spectroscopy. The results of calculations, experiments with various electron sources as well as a first test with trapped radioactive ions are presented.

Abstract: The present status of mass measurements from reactions producing nuclei at the driplines, including those unstable to nucleon or cluster emission, is discussed. The results of recent heavy ion and π-meson induced experiments on the study of the superheavy hydrogen isotopes (4H, 5H, 6H), helium (9He, 10He), lithium (10Li, 11Li) and beryllium (13Be) are given. The possibilities of mass measurements in radioactive ion beam experiments are also considered.

Abstract: The QCMC scheme created earlier for cascade calculations in heavy hadronic atoms of hydrogen isotopes has been modified and applied to the study of cascade processes in the μp muonic hydrogen atoms. The distribution of μp atoms over kinetic energies has been obtained and the yields of K-series X-rays per one stopped muon have been calculated.

Abstract: A thermodynamic model for site preferences of solute atoms in ordered binary phases is applied in this paper for substitutional and interstitial sites of the Cu3Au, or L12, structure. Site preferences are found to depend on formation energies of combinations of elementary point defects and on energies for transfer of solutes among different sites. The composition dependence in compounds having a wide phase field is examined in detail. A phenomenology of site preference behavior is outlined for regular lattice sites as well as for non-lattice sites such as grain boundaries.

Abstract: An empirical expression for the dependence of the magnetic hyperfine field on the aluminium content and the particle size in iron oxides and oxyhydroxides is often used in Mossbauer studies of soil samples. According to this expression, the reduction of the hyperfine field in nanometer-sized particles should be proportional to the inverse particle diameter. This is apparently in disagreement with the expression for the influence of collective magnetic excitations on the magnetic hyperfine field, which predicts a reduction proportional to the inverse volume. It is shown that this apparent discrepancy in the case of non-interacting hematite nanoparticles (accidentally) can be explained by the size dependence of the magnetic anisotropy constant. However, it is also pointed out that a third parameter, namely the strength of the inter-particle interactions, can have a significant influence on the magnetic hyperfine splitting in Mossbauer spectra of magnetic nanoparticles. Therefore, an analysis of data, based on the empirical expression, which only takes into account the particle size and the aluminium content, can give erroneous results.

Abstract: Recent theoretical calculations show for defect complexes in semiconductors, characterized by electric field gradients (EFG), that their chemical compositions, electronic charge states and the induced lattice relaxations can be obtained by comparing the experimental and calculated EFG. The experimental data are obtained by perturbed γγ angular correlation experiments and the calculations are performed using ab initio full potential methods in the framework of density functional theory.

Abstract: It was confirmed by detecting the β-NMR of 12B (I π=1+, T 1/2=20.2 ms) in a TiO2 (rutile) crystal that the nuclear spin polarization of 12B was totally maintained in the crystal as produced through a nuclear reaction before implantation. Two locations, site 1 and site 2, were found with the relative populations 9 and 1, respectively, and the electric field gradients (EFGs) at those sites were obtained to be q(site 1)=+(37.1±0.5)1015 V/cm2, η(site 1)<0.03, q(site 2)=+(185±5)1015 V/cm2 and η(site 2)=0.62±0.02. We also found that about 30% of the initial polarization of 8Li (I π=2+, T 1/2=838 ms) was maintained in the crystal. Since the polarizations of other β emitting nuclei, 12,16N, 13,19O, and 41Sc were also totally maintained in the crystal, the crystal can be a “Spin Dewar” in which many short-lived nuclides can be implanted with their polarizations totally maintained during their lifetimes for the studies not only on the electronic structure of impurities in it but also on the nuclear properties.

Abstract: Fe x Cu100−x magnetoresistive alloys were produced by mechanical alloying. X-ray diffraction shows fcc structure. The room-temperature Mossbauer spectra evolves from an asymmetrical doublet below x=25%, to a broad magnetic hyperfine field distribution above this concentration. Quadrupole splitting of the doublet varies between 0.48 and 0.57 mm/s, and its isomer shift from 0.16 to 0.29 mm/s. Low-temperature Mossbauer spectroscopy displays a B hf distribution. Magnetization measurements display different features depending on concentration, from mictomagnetism to ferromagnetism. Low-temperature magnetoresistance is measured. Samples with x∼20% exhibit larger magnetoresistivity ratios. Bulk and hyperfine magnetic properties are correlated in order to explain magnetoresistivity features of these samples.

Abstract: The ion trap facility SHIPTRAP is being set up to deliver very clean and cool beams of singly-charged recoil ions produced at the SHIP velocity filter at GSI Darmstadt. SHIPTRAP consists of a gas cell for stopping and thermalizing high-energy recoil ions from SHIP, an rf ion guide for extraction of the ions from the gas cell, a linear rf trap for accumulation and bunching of the ions, and a Penning trap for isobaric purification. The progress in testing the rf ion guide is reported. A transmission of about 93(5)% was achieved.

Abstract: In this work we show that mechano-synthesis is a good method to prepare the FeSiB amorphous alloy starting from Fe, Si, B pure elements with relative atomic composition of 75, 15 and 10%, respectively. We have used a high-energy ball-milling system keeping the material under an Ar atmosphere. The evolution of the microstructure inside the grains is followed by X-ray diffraction and Mossbauer spectroscopy at room temperature. The dependence of crystalline size, lattice parameter and hyperfine parameters on milling time is discussed. Our results show that the milled samples obtained after 10 h of milling contained a bcc structure in the amorphous matrix. After 19 h of milling the sample became fully amorphous.

Abstract: A review of the Muon Catalyzed Fusion theory after the International Symposium EXAT-98 is presented. The main results obtained are discussed. Special attention is paid to the unsolved problems of the μCF phenomenon and its applications.

Abstract: We report an ab initio study of the electric-field gradient (EFG) at Cd impurities located at the cation site in the semiconductor SnO2(rutile phase). The study was performed with the WIEN97 implementation of the FP-LAPW method. In order to simulate the diluted Cd-impurity in the SnO2 host and to calculate the electronic structure of the system we used a 72-atoms super-cell, studying the relaxation introduced by the impurity in the lattice. The free-relaxation process performed shows that the relaxations of the oxygen nearest-neighbors of the impurity are not isotropic. Our prediction for the EFG tensor are compared with experimental results and point-charge model predictions.