Max-Planck-Institut Fur Kernphysik Research Articles

An electron beam ion trap and source for re-acceleration of rare-isotope ion beams at TRIUMF.

Electron beam driven ionization can produce highly charged ions (HCIs) in a few well-defined charge states. Ideal conditions for this are maximally focused electron beams and an extremely clean vacuum environment. A cryogenic electron beam ion trap fulfills these prerequisites and delivers very pure HCI beams. The Canadian rare isotope facility with electron beam ion source-electron beam ion sources developed at the Max-Planck-Institut für Kernphysik (MPIK) reaches already for a 5 keV electron beam and a current of 1 A with a density in excess of 5000 A/cm2 by means of a 6 T axial magnetic field. Within the trap, the beam quickly generates a dense HCI population, tightly confined by a space-charge potential of the order of 1 keV times the ionic charge state. Emitting HCI bunches of ≈107 ions at up to 100 Hz repetition rate, the device will charge-breed rare-isotope beams with the mass-over-charge ratio required for re-acceleration at the Advanced Rare IsotopE Laboratory (ARIEL) facility at TRIUMF. We present here its design and results from commissioning runs at MPIK, including X-ray diagnostics of the electron beam and charge-breeding process, as well as ion injection and HCI-extraction measurements.

Large Scale Production of the Liquid Scintillator for the Double Chooz Experiment

Techniques and achievements built in Max-Planck-Institut für Kernphysik (MPIK) are discussed for multi-ton scale production of Double Chooz liquid scintillator.

PENTATRAP: a novel cryogenic multi-Penning-trap experiment for high-precision mass measurements on highly charged ions

The novel five-Penning-trap mass spectrometer Pentatrap is developed at the Max-Planck-Institut für Kernphysik (MPIK), Heidelberg. Ions of interest are long-lived highly charged nuclides up to bare uranium. Pentatrap aims for an accuracy of a few parts in 1012 for mass ratios of mass doublets. A physics program for Pentatrap includes Q-value measurements of β-transitions relevant for neutrino physics, stringent tests of quantum electrodynamics in the regime of extreme electric fields, and a test of special relativity. Main features of Pentatrap are an access to a source of highly charged ions, a multi-trap configuration, simultaneous measurements of frequencies, a continuous precise monitoring of magnetic field fluctuations, a fast exchange between different ions, and a highly sensitive cryogenic non-destructive detection system. This article gives a motivation for the new mass spectrometer Pentatrap, presents its experimental setup, and describes the present status.

Publisher’s Note: Semiconductor cavity QED with squeezed light: Nonlinear regime [Phys. Rev. A84, 053817 (2011)

This paper was published online on 9 November 2011 with an incorrect affiliation and an omission of an author footnote. Sumanta Das’s affiliation should read as “3Zur Forstquelle 6, 69126 Heidelberg, Germany”, and his footnote should read as “*Currently at Max-Planck Institut fur Kernphysik, Heidelberg, Germany.”. The paper has been corrected as of 5 January 2012. The author affiliation is incorrect and the footnote is missing in the printed version of the journal.

The attosecond beamline at MPIK

We report on the status of the attosecond beamline newly built at Max-Planck-Institut für Kernphysik (MPIK), Heidelberg, and ongoing experiments. The beamline is designed for detailed investigation of the electronic response in atoms and molecules by combining a versatile HHG-source with a compact reaction microscope.

The production of platinum-coated silicate nanoparticle aggregates for use in hypervelocity impact experiments

We present a method for producing metal-coated low-density (≲1600 kg m −3) aggregate silicate dust particles for use in hypervelocity impact (HVI) experiments. Particles fabricated using the method are shown to have charged and electrostatically accelerated in the Max Planck Institut für Kernphysik (MPI-K) 2 MV Van de Graaff accelerator, allowing the production of impact ionisation mass spectra of silicate particles (impacting at velocities ranging from <4 to >30 km s −1, corresponding to sizes of >1 to <0.1 μm) using the large area mass analyser (LAMA) instrument, designed for cosmic dust detection in space. Potential uses for the coated grains, such as in the calibration of aerogel targets similar to those used on the Stardust spacecraft, are also discussed.

Numerical simulation of grazing impacts from micron sized particles on the XMM-newton mirrors

This paper presents the results of numerical simulations of micron-sized particles hypervelocity impacts on the XMM telescope mirror surfaces at grazing angles. The scope of the study was to demonstrate the possibility that very high energy peaks detected by the Charge Coupled Devices (CCDs) placed at the end of the mirror surfaces were caused by micrometeoroid impacts. First simulated were tests performed with the dust accelerator of Max Planck Institut fur Kernphysik (Heidelberg, Germany) at impact velocities around 5 km/s and impact angles between 1 and 5 degrees from the mirror surface plane. The results showed the projectile leaving the target plastically deformed but not fragmented with an exit angle much smaller than the entry one, thus confirming the experimental evidence that some material travelling after the impact close to the target surface reached the location of CCDs. Additional simulations with iron projectiles were performed at increasing impact angles up to 45° from the mirror surface plane. They showed that the amount of material leaving after impact nearly parallel to the mirror surface progressively diminishes due to the onset of projectile fragmentation and scattering, but some material is still found even for high impact angles. This effect is probably due to the high density of the gold coating layer of the XMM mirror, as it was not observed in analogous simulations with a softer aluminium coating. In order to better approximate the conditions of a real natural meteoroid impact, simulations at I -degree incidence and velocities up to 30 km/s were performed with aluminium projectiles, whose density is closer to the expected values for meteoroids in space. The results showed that the velocity increase induces more projectile erosion phenomena in the contact zone with the target, further reducing the exit angle. Above 20 km/s the projectile exit path is practically parallel to the mirror surface, thus supporting the hypothesis that a micrometeoroid impacting at grazing angle on the mirror surface can find its way up to the XMM CCDs focal plane.

The Gas Field Ion Source for Finely Focused Ion Beam Systems

AbstractThe Gas Field Ion Source, GFIS, promises a 109A/(cm2 str) brightness, small beam sizes, and inert gas ion species. If this performance could be demonstrated on a commercial system, the GFIS might replace the liquid metal ion source as the standard source for FIB applications. Recent work at the Max-Planck-Institut für Kernphysik (MPI-K) in Heidelberg, Germany has shown that a GFIS with a ‘Super Tipped’ emitter can be reliably fabricated and can be run with stable helium beam current for more than 200 hours. However, this GFIS source must operate in a bakable UHV chamber, at cryogenic temperatures, and at high voltages with low vibration. A GFIS is now being integrated with high resolution ion optics and a vacuum chamber designed for studying GFIS image quality and ion induced chemistry.