[en] The nuclear masses reflect the sum of all interactions inside a nucleus. Their precise knowledge can be used to benchmark nuclear mass models and to gain nuclear structure information. Penning-trap mass spectrometers have proven their potential to obtain lowest uncertainties. Uniquely located at a nuclear reactor, the double Penning-trap mass spectrometer TRIGA-TRAP is dedicated to measurements in the neutron-rich region. For a gain in sensitivity a non-destructive detection system for single ion mass measurements was adopted. This includes the implementation of a narrow band-pass filter tuned to the heavy ion cyclotron frequency as well as a cryogenic low-noise amplifier. For on-line mass measurements, the laser ablation ion source was equipped with a newly developed miniature radiofrequency quadrupole trap in order to improve the extraction efficiency. A more economic use of the radioactive material enabled mass measurements using only 10¹⁵ atoms of target material. New mass measurements were performed within this work in the realm of the deformed shell closure N=152. Their implementation into the atomic-mass evaluation improved the uncertainty of more than 80 nuclides in the heavy mass region and simultaneously shifted the absolute mass of two α decay chains.

[en] TRIGA-SPEC is a setup for Penning trap mass spectrometry and collinear laser spectroscopy on short-lived neutron-rich nuclides located at the research reactor TRIGA-Mainz. It is dedicated to the determination of nuclear ground-state properties like masses and charge-radii. The nuclides are produced by neutron-induced fission of an actinide target located in a target chamber near the reactor core. It is required to extract the nuclides fast and with high efficiency from the target chamber in order to make precision experiments on short-living species with half-lives in the order of 1s. To this end, they are flushed out with a helium gas jet containing carbon aerosols and transported through a skimmer region to an ECR ion source. The characterisation of the carbon aerosol generator and the verification of transported fission products are presented

[en] TRIGA-TRAP is a facility which aims for mass measurements on neutron-rich short-lived fission products and actinides with relative mass uncertainties of 10^-7 and below. To this end the cyclotron frequency of a stored ion in a Penning trap is determined. In high-precision mass spectrometry the investigation of systematic errors is of utmost importance. In order to demonstrate the accuracy of the measured values, various carbon cluster ions have been used in cross reference measurements. The results are presented and the accuracy limit of TRIGA-TRAP is discussed

[en] Nuclear masses represent the binding energies and, therefore, the sum of all interactions in the nucleus. They provide an important input parameter to nuclear structure models. Presently, a tremendous interest in masses of very exotic neutron-rich nuclides exists to support theoretical models for the nucleosynthesis via the rapid neutron capture process. The research reactor TRIGA Mainz provides access to a large variety of neutron-rich nuclides produced by thermal-neutron induced fission of an actinide target. The double-Penning trap mass spectrometer TRIGA-TRAP will perform high-precision mass measurements in this region of the nuclear chart as well as on actinides from uranium to californium. It also serves as a test facility for the development of new techniques that will be implemented in future facilities like MATS at FAIR (GSI, Darmstadt). The layout of TRIGA-TRAP as well as recent mass measurements are presented

[en] Nuclear structure and astrophysics studies rely heavily on precision mass measurements of rare isotopes. However, many of these isotopes far from the valley of stability can only be produced at very low rates, which are incompatible with the destructive measurement techniques used by rare isotope Penning trap mass spectrometry facilities. To this end, the Low Energy Beam and Ion Trap facility at the National Superconducting Laboratory is in the process of commissioning a single ion Penning trap (SIPT) mass spectrometer that relies on the non-destructive narrowband Fourier Transform ion cyclotron resonance technique. SIPT is the first Penning trap designed to perform mass measurements of rare isotopes produced via projectile fragmentation at rates on the order of one ion per day. The system details and cryogenic detection design, as well as results from the room and cryogenic temperature commissioning, are discussed at length.

[en] Tests of nuclear mass models, studies of the nuclear structure of heavy elements and calculations of the astrophysical r-process require high precision atomic mass data. For this purpose the double Penning trap mass spectrometer TRIGA-TRAP has recently been set up in order to explore the less-known neutron-rich area of the nuclide chart. Certain nuclides of interest are produced by thermal neutron-induced fission of an actinoide target with low rates, in the order of a few nuclides per second or less. Thus, the implementation of very efficient means of detection are necessary, such as the non-destructive Fourier transform ion cyclotron resonance (FT-ICR) technique where ultimately a single trapped ion, with a half-life of longer than one second is sufficient for the entire mass measurement. The present status of the implementation of the FT-ICR detection at TRIGA-TRAP is presented. The potential benefit for other experiments is discussed.

[en] The TRIGA-SPEC experiment has been installed recently at the research reactor TRIGA Mainz. Ground state properties like masses, charge radii, spins, and moments of short-lived nuclides can be determined with very-high precision using the Penning trap mass spectrometer TRIGA-TRAP, and the collinear laser spectroscopy setup TRIGA-LASER. Short-lived neutron-rich radionuclides in the mass range 80 < A < 140 are produced by thermal neutron induced fission of e.g. U-235, Pu-239 or Cf-249, respectively. For the extraction and ionization of the fission products a gas-jet system is coupled to a 2.45-GHz ECR ion source for the production of singly charged ions. The gas-jet has been tested on-line and fission products have been extracted. First off-line tests of the ion source have been performed successfully with argon gas. The results of the commissioning test of the ion source and the on-line coupling of the experiments are presented.

[en] The double Penning trap mass spectrometer TRIGA-TRAP will perform high-precision mass measurements on exotic neutron-rich nuclides, which are produced via neutron-induced fission of actinide targets at the research reactor TRIGA Mainz. In order to determine which ion species are present in the ion bunch delivered to the Penning trap system, a non-destructive ion detection technique will be implemented in the cylindrical purification trap. This so called broad-band Fourier transform ion cyclotron resonance (FT-ICR) detection technique is based on the detection of image currents, induced by the ions in the trap electrodes. To this end, a new cryogenic low-noise broad-band amplifier is being designed and tested. With this system the identification of contaminations will be possible without the need to eject ions from the trap as usually done at other facilities. The setup as well as its present status are presented

[en] Precise experimental data of the ground-state properties of short-lived nuclides are required to test the predictive power of nuclear mass models and to support nucleosythesis calculations of the astrophysical r-process. Besides the measurement of these properties with high precision, the creation and preparation of the nuclides of interest is one of the biggest challenges in this field of physics. So far, mostly the proton-rich side of the nuclear chart could be reached at various research facilities by bombarding a heavy target with light particles. For the TRIGA-SPEC experiment located at the TRIGA reactor in Mainz, nuclides of the neutron-rich side of the nuclear chart can be created by neutron-induced fission of an actinide target inside the reactor. The online coupling is going to be realized with an aerosol-loaded gas-jet system, an ion source, a separator magnet, and an RFQ quadrupole for ion beam cooling and bunching. The coupling of the already working mass spectrometer TRIGA-TRAP and laser-spectroscopy setup TRIGA-LASER to the reactor will be finished in the near future. An overview of the online coupling and the ion beam preparation as well as possible alternatives is presented. The TRIGA-TRAP mass spectrometer and the TRIGA-LASER laser spectroscopy setup, forming the TRIGA-SPEC experiment, were recently installed at the research reactor TRIGA Mainz in order to perform high-precision measurements of the ground state properties of short-lived neutron-rich radionuclides in the mass range 80< A<140. The radionuclides are produced by thermal neutron-induced fission in an actinide target inside the reactor, extracted by a gas-jet system, and ionized by an ECR ion source. The ions of interest will then be mass-separated in a 90 ^circle dipole magnet. An RFQ buncher is being installed to accumulate, cool and bunch the ion beam. It will reduce the ion beam's emittance using buffer gas cooling in Helium and accumulate bunches of up to 10⁵ singly-charged ions. A following switchyard will then connect TRIGA-TRAP and TRIGA-LASER to the extraction part of the setup. The status of the implementation of the dipole magnet and the RFQ buncher is presented. TRIGA-TRAP is so far the only Penning-trap mass spectrometer installed at a nuclear research reactor worldwide. Its scientific goal is the high-precision mass measurement of neutron-rich fission products being prepared in the TRIGA reactor in Mainz. Precise experimental mass data in the region towards the island of stability of the nuclear chart are required to test nuclear mass models and to support the nucleosynthesis calculations of the astrophysical r-process. The production of the nuclides of interest is performed by thermal neutron-induced fission of an actinide target with rates of a few nuclides per second or less.

[en] At the TRIGA research reactor in Mainz the TRIGA-SPEC setup is under construction. The aim is to perform Penning trap mass spectrometry and collinear laser spectroscopy on short-lived neutron-rich nuclides. The nuclides are produced by neutron-induced fission of an actinide target located in a target chamber close to the reactor core. A key issue is the extraction of these nuclides from the target chamber through the biological shield of the reactor, and ultimately the preparation of a mass-selected, cooled and bunched low energy ion sample for high-precision experiments on nuclides with half-lives in the order of 1 s. The current status of TRIGA-SPEC is presented.