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Nuclear ground state properties including mass, charge radii, spins and moments can be determined by applying atomic physics techniques such as Penning-trap based mass spectrometry and laser spectroscopy. The MATS and LaSpec setups at the low-energy beamline at FAIR will allow us to extend the knowledge of these properties further into the region far from stability.The mass and its inherent connection with the nuclear binding energy is a fundamental property of a nuclide, a unique “fingerprint”. Thus, precise mass values are important for a variety of applications, ranging from nuclear-structure studies like the investigation of shell closures and the onset of deformation, tests of nuclear mass models and mass formulas, to tests of the weak interaction and of the Standard Model. The required relative accuracy ranges from 10−5to below 10−8for radionuclides, which most often have half-lives well below 1 s. Substantial progress in Penning trap mass spectrometry has made this method a prime choice for precision measurements on rare isotopes. The technique has the potential to provide high accuracy and sensitivity even for very short-lived nuclides. Furthermore, ion traps can be used for precision decay studies and offer advantages over existing methods.With MATS (Precision Measurements of very short-lived nuclei using an A_dvanced Trapping System for highly-charged ions) at FAIR we aim to apply several techniques to very short-lived radionuclides: High-accuracy mass measurements, in-trap conversion electron and alpha spectroscopy, and trap-assisted spectroscopy. The experimental setup of MATS is a unique combination of an electron beam ion trap for charge breeding, ion traps for beam preparation, and a high-precision Penning trap system for mass measurements and decay studies. For the mass measurements, MATS offers both a high accuracy and a high sensitivity. A relative mass uncertainty of 10−9can be reached by employing highly-charged ions and a non-destructive Fourier-Transform Ion-Cyclotron-Resonance (FT-ICR) detection technique on single stored ions. This accuracy limit is important for fundamental interaction tests, but also allows for the study of the fine structure of the nuclear mass surface with unprecedented accuracy, whenever required. The use of the FT-ICR technique provides true single ion sensitivity. This is essential to access isotopes that are produced with minimum rates which are very often the most interesting ones. Instead of pushing for highest accuracy, the high charge state of the ions can also be used to reduce the storage time of the ions, hence making measurements on even shorter-lived isotopes possible.Decay studies in ion traps will become possible with MATS. Novel spectroscopic tools for in-trap high-resolution conversion-electron and charged-particle spectroscopy from carrier-free sources will be developed, aiming e.g. at the measurements of quadrupole moments and E0 strengths. With the possibility of both high-accuracy mass measurements of the shortest-lived isotopes and decay studies, the high sensitivity and accuracy potential of MATS is ideally suited for the study of very exotic nuclides that will only be produced at the FAIR facility.Laser spectroscopy of radioactive isotopes and isomers is an efficient and model-independent approach for the determination of nuclear ground and isomeric state properties. Hyperfine structures and isotope shifts in electronic transitions exhibit readily accessible information on the nuclear spin, magnetic dipole and electric quadrupole moments as well as root-mean-square charge radii. The dependencies of the hyperfine splitting and isotope shift on the nuclear moments and mean square nuclear charge radii are well known and the theoretical framework for the extraction of nuclear parameters is well established. These extracted parameters provide fundamental information on the structure of nuclei at the limits of stability. Vital information on both bulk and valence nuclear properties are derived and an exceptional sensitivity to changes in nuclear deformation is achieved. Laser spectroscopy provides the only mechanism for such studies in exotic systems and uniquely facilitates these studies in a model-independent manner.The accuracy of laser-spectroscopic-determined nuclear properties is very high. Requirements concerning production rates are moderate; collinear spectroscopy has been performed with production rates as few as 100 ions per second and laser-desorption resonance ionization mass spectroscopy (combined with β-delayed neutron detection) has been achieved with rates of only a few atoms per second.This Technical Design Report describes a new Penning trap mass spectrometry setup as well as a number of complementary experimental devices for laser spectroscopy, which will provide a complete system with respect to the physics and isotopes that can be studied. Since MATS and LaSpec require high-quality low-energy beams, the two collaborations have a common beamline to stop the radioactive beam of in-flight produced isotopes and prepare them in a suitable way for transfer to the MATS and LaSpec setups, respectively.

Nuclear ground state properties including mass, charge radii, spins and moments can be determined by applying atomic physics techniques such as Penning-trap based mass spectrometry and laser spectroscopy. The MATS and LaSpec setups at the low-energy beamline at FAIR will allow us to extend the knowledge of these properties further into the region far from stability.

Abstract: Nuclear ground state properties including mass, charge radii, spins and moments can be determined by applying atomic physics techniques such as Penning-trap based mass spectrometry and laser spectroscopy. The MATS and LaSpec setups at the low-energy beamline at FAIR will allow us to extend the knowledge of these properties further into the region far from stability. The mass and its inherent connection with the nuclear binding energy is a fundamental property of a nuclide, a unique “fingerprint”. Thus, precise mass values are important for a variety of applications, ranging from nuclear-structure studies like the investigation of shell closures and the onset of deformation, tests of nuclear mass models and mass formulas, to tests of the weak interaction and of the Standard Model. The required relative accuracy ranges from 10−5 to below 10−8 for radionuclides, which most often have half-lives well below 1 s. Substantial progress in Penning trap mass spectrometry has made this method a prime choice for precision measurements on rare isotopes. The technique has the potential to provide high accuracy and sensitivity even for very short-lived nuclides. Furthermore, ion traps can be used for precision decay studies and offer advantages over existing methods. With MATS (Precision Measurements of very short-lived nuclei using an A_dvanced Trapping System for highly-charged ions) at FAIR we aim to apply several techniques to very short-lived radionuclides: High-accuracy mass measurements, in-trap conversion electron and alpha spectroscopy, and trap-assisted spectroscopy. The experimental setup of MATS is a unique combination of an electron beam ion trap for charge breeding, ion traps for beam preparation, and a high-precision Penning trap system for mass measurements and decay studies. For the mass measurements, MATS offers both a high accuracy and a high sensitivity. A relative mass uncertainty of 10−9 can be reached by employing highly-charged ions and a non-destructive Fourier-Transform Ion-Cyclotron-Resonance (FT-ICR) detection technique on single stored ions. This accuracy limit is important for fundamental interaction tests, but also allows for the study of the fine structure of the nuclear mass surface with unprecedented accuracy, whenever required. The use of the FT-ICR technique provides true single ion sensitivity. This is essential to access isotopes that are produced with minimum rates which are very often the most interesting ones. Instead of pushing for highest accuracy, the high charge state of the ions can also be used to reduce the storage time of the ions, hence making measurements on even shorter-lived isotopes possible. Decay studies in ion traps will become possible with MATS. Novel spectroscopic tools for in-trap high-resolution conversion-electron and charged-particle spectroscopy from carrier-free sources will be developed, aiming e.g. at the measurements of quadrupole moments and E0 strengths. With the possibility of both high-accuracy mass measurements of the shortest-lived isotopes and decay studies, the high sensitivity and accuracy potential of MATS is ideally suited for the study of very exotic nuclides that will only be produced at the FAIR facility.Laser spectroscopy of radioactive isotopes and isomers is an efficient and model-independent approach for the determination of nuclear ground and isomeric state properties. Hyperfine structures and isotope shifts in electronic transitions exhibit readily accessible information on the nuclear spin, magnetic dipole and electric quadrupole moments as well as root-mean-square charge radii. The dependencies of the hyperfine splitting and isotope shift on the nuclear moments and mean square nuclear charge radii are well known and the theoretical framework for the extraction of nuclear parameters is well established. These extracted parameters provide fundamental information on the structure of nuclei at the limits of stability. Vital information on both bulk and valence nuclear properties are derived and an exceptional sensitivity to changes in nuclear deformation is achieved. Laser spectroscopy provides the only mechanism for such studies in exotic systems and uniquely facilitates these studies in a model-independent manner.The accuracy of laser-spectroscopic-determined nuclear properties is very high. Requirements concerning production rates are moderate; collinear spectroscopy has been performed with production rates as few as 100 ions per second and laser-desorption resonance ionization mass spectroscopy (combined with β-delayed neutron detection) has been achieved with rates of only a few atoms per second.This Technical Design Report describes a new Penning trap mass spectrometry setup as well as a number of complementary experimental devices for laser spectroscopy, which will provide a complete system with respect to the physics and isotopes that can be studied. Since MATS and LaSpec require high-quality low-energy beams, the two collaborations have a common beamline to stop the radioactive beam of in-flight produced isotopes and prepare them in a suitable way for transfer to the MATS and LaSpec setups, respectively.

Energy requirements for ingestion and standing were determined in open-circuit respiration chambers with four ruminally cannulated German Red Pied steers weighing 617 ± 53 kg of BW (mean ± SD). The requirement for standing over lying was derived by regressing heat production on time spent standing within 2-h periods when no feed was offered to avoid any interference with eating activity, and amounted to 14 kJ/(d•kg of BW). The energy requirement for ingestion was determined by calculating the difference between heat production during a 2-h period without feed and during a consecutive 2-h period in which straw of different particle sizes, fresh and conserved grass, or rolled barley were offered for ad libitum intake. Before measurements, the rumens of the steers were emptied, washed, and filled with a buffer solution to avoid heat production by metabolism of absorbed nutrients from the feed ingested during the experimental periods. The mean value for all feeds tested was 20 J/(min of ingestion • kg BW). Relating heat production to the amount of DM or fiber ingested did not decrease variation among feeds. This confirms the observations of earlier studies, that energy requirement for ingestion is mainly determined by time spent eating. Results of additional measurements, in which the same amounts of the respective feeds ingested in preceding periods were put into the emptied rumens via the cannulas, showed that the presence of the feed in the rumen did not increase heat production, indicating that the increment of heat production during eating is mainly caused by ingesting and chewing the feed. Further measurements in the same animals with an ingesta-filled rumen showed that ingestion of straw led to an increase in heat production per minute of chewing similar to those with emptied rumens, which confirms the validity of the experimental procedure using ruminally emptied animals to determine the energy requirement for ingestion.

This study tested the hypothesis that the effect of lysine intake, if first-limiting, on protein retention in growing pigs is completely independent of the effects of energy intake, differences in the protein retention capacity among genotypes and gender, and body weight. Protein retention, using the nitrogen balance technique, was measured in 12 castrated male German Landrace and Pietrain pigs at 44 and 77 kg of BW and at two energy intake levels (1.1 and 1.3 MJ ME/kg BW.75). All animals received a constant amount of a basal diet that provided a protein intake of 220 g/d and a total lysine intake of 13 g/d. Appropriate amounts of cornstarch were offered additionally to reach the intended energy intake levels. The results show that neither energy intake nor breed had any effect on the level of protein retention, whereas, at 77 kg BW, protein retention was significantly lower than at 44 kg (117.8 and 123.5 g/d, respectively), which can be attributed to the higher requirement for maintenance. The results of this experiment and the linearity of the relationship between protein retention and lysine intake as shown by several authors simplify both the prediction of protein retention from lysine intake and the calculation of the lysine requirement for a particular protein retention. However, to ensure accuracy of these predictions, it is essential to know when ratios of lysine to other amino acids and to energy and capacity for protein retention in the animal become first-limiting.

Es wird ein numerisches Lösungsverfahren zur Integration von Systemen nichtlinearer, partieller Differentialgleichungen für eine Theorie geometrisch nichtlinearer, schubelastischer Flächentragwerke vorgestellt. Der Algorithmus ist in die Gruppe der inkrementellen und iterativen Verfahren einzuordnen. Zur Diskretisierung wird ein Mehrstellenverfahren verwendet. Die wichtige Frage der Überwindung von Singularitäten wird umfassend beantwortet. Schließlich kann die Leistungsfähigkeit der Methode bei der numerischen Behandlung von Aufgaben aus der Stabilitätstheorie und der nichtlinearen Spannungstheorie demonstriert werden.

A novel system consisting of RF quadrupole and time-of-flight sections is proposed, in which ions can be cooled, bunched, mass separated with a resolution sufficient to differentiate between isobars, and guided to different experimental setups, e.g. for precision mass measurements or mass-resolved decay spectroscopy. It enables multiplexed operation of several connected experiments and interleaved measurements using different nuclides in one connected experiment. Such a system could be employed advantageously at in-flight facilities, at which experiments with stopped exotic nuclei are made possible using gas-filled stopping cells, such as SHIPTRAP at GSI, or potentially at ISOL facilities. First results for individual stages of the system are presented.

Abstract.: A novel system consisting of RF quadrupole and time-of-flight sections is proposed, in which ions can be cooled, bunched, mass separated with a resolution sufficient to differentiate between isobars, and guided to different experimental setups, e.g. for precision mass measurements or mass-resolved decay spectroscopy. It enables multiplexed operation of several connected experiments and interleaved measurements using different nuclides in one connected experiment. Such a system could be employed advantageously at in-flight facilities, at which experiments with stopped exotic nuclei are made possible using gas-filled stopping cells, such as SHIPTRAP at GSI, or potentially at ISOL facilities. First results for individual stages of the system are presented.

A novel system consisting of RF quadrupole and time-of-flight sections is proposed, in which ions can be cooled, bunched, mass separated with a resolution sufficient to differentiate between isobars, and guided to different experimental setups, e.g.?for precision mass measurements or mass-resolved decay spectroscopy. It enables multiplexed operation of several connected experiments and interleaved measurements using different nuclides in one connected experiment. Such a system could be employed advantageously at in-flight facilities, at which experiments with stopped exotic nuclei are made possible using gas-filled stopping cells, such as SHIPTRAP at GSI, or potentially at ISOL facilities. First results for individual stages of the system are presented.