The detection of gravitational waves and the two body problem in general relativity
The recent successful detection of gravitational waves has been a century long Odyssey involvinga remarkable experiment and an elegant theory. In the latter aspect, it was made possible by a critical understanding of physical effects of gravitational waves and an improved understanding of the problem of two body motion in general relativity. This talk is a personal broad brush overview of how an unforgiving experiment drove an exquisite theory to create a sophisticated data analysis infrastructure to detect gravitational waves and to decipher their properties.
16/01/2018 at 4:00 pm
Preeti Manjari Mishra,Postdoctoral Researcher, Max Planck Institute for Nuclear Physics, Germany
SEMINAR OF GENERAL INTEREST
IOP Lecture Hall
Document Date:
Photoexcitation spectroscopy of cold molecules in the Cryogenic Storage Ring “CSR”
Photoexcitation spectroscopy of cold molecules in the Cryogenic Storage Ring “CSR”
The Cryogenic Storage Ring (CSR) [1] located at Max-Planck-Institut für Kernphysik in Heidelberg,Germany is an ideal experimental setup to perform collision studies of photons and cold electrons as well neutrals with the stored molecular ions of kinetic energies between 20-300 keV. The circumference of the ring is 35 m and being fully electrostatic, it has no mass limit for stored ions. The cryogenic temperature of about 6 K offers unique storage capabilities in extremely high vacuum conditions of below 140 rest-gas particles per cm3 and almost vanishing blackbody radiation. An electron cooler(ecool) is installed in one straight section of the CSR which uses a photocathode to produce cold electrons. These cold electrons can further reduce the momentum spread of the stored ion beam upon interaction. A tunable optical parametric oscillator (OPO) laser system in the same section allows photon interaction studies from the ultraviolet (225 nm) to the infrared (2600 nm) regime. The CSR is equipped with two independent ion source platforms, which can deliver ions up to an energy of 60 and 300 keV per charge state, respectively. The low energy platform can be used to produce neutral beams by photodetachment of the negative ions. Whereas the 300 kV platform presently contains a metal ion sputter source, a Penning source and an electron cyclotron resonance source; extension by a laser vaporization and an electrospray ionization ion source is in progress. The entire facility enables to perform photodissociation, electron-ion recombination, and ion-atom interaction studies with ro-vibrationally cooled stored positive and negative ions as well as clusters and highly charged ions. Further experiments aim to study decay rates of metastable ions and radiative lifetimes. The first experimental results,machine characteristics as well as future experimental possibilities of this unique infrastructure will be discussed [2, 3].
References
[1] R. von Hahn, et al., Rev. Sci. Instrum. 87, 063115 (2016).
[2] A. O’ Connor, et al., Phys. Rev. Lett. 116, 113002 (2016).
[3] C. Meyer, et al., Phys. Rev. Lett. 119, 023202 (2017).