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A 2nd-generation gravitational neutron spectrometer

The GRANIT project consists of designing and building a second-generation gravitational neutron spectrometer with ultra-high resolution. Its key property is the storage of UCN in a selected gravitationally bound state for extended period of time using a closed specula trap. The high quality of mirrors needed for the trap is at the edge of modern technology.

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Applications

Applications

Particle physics and fundamental interactions, e.g.:

  • refined measurement of the electrical charge of the neutron
  • spin-dependent or spin-independent short-range forces
  • the search for the axion,
  • the search for other additional forces beyond the standard model

Foundations of quantum mechanics, e.g.:

  • loss of quantum coherence

Solid-state physics

Experimental techniques and their possible technological applications.

The neutron whispering gallery effect

The whispering gallery effect is well know for sound waves. The GRANIT team will use it for neutron experiments. The existence of the phenomenon was proved by an experiment preformed on the D17 reflectometer. This is the first experimental evidence for neutron localization (whispering gallery wave) in the quasistationary quantum states near a cylindrical mirror surface. The boundary effective well is formed by the centrifugal effective potential and the mirror neutron–matter optical potential

Ref.: The whispering gallery effect in neutron scattering, V. V. Nesvizhevsky, R. Cubitt, K. V. Protasov and A. Yu Voronin, New J. Phys. 12 113050, 2010.

The movie of an interview of Valey Nesvizhevsky and Andrei Yu Voronin can be found HERE.



Image courtesy of Alain Filhol, Institut Laue-Langevin.

Here a schematic illustration of the neutron whispering gallery demonstrated by Nesvizhevsky et al.
The insert shows the triangularly shaped potential above the material and the lowest quantum states within such a potential.

Ref.: Quantum optics: Neutrons in a whispering gallery, Helmut Rauch, Nature Physics 6, 79-80 (2010).