Construction and testing of the instrument for neutron holographic study at the Budapest Research Reactor.

Neutron scattering device dedicated to neutron holography experiments is described. The device is operating at a constant wavelength prepared by a double focusing monochromator. It is equipped by highly efficient shielding, proper collimator, Eulerian cradle, monitor detector, gamma-ray, and neutron detectors as well.

Study of the reflectivity of neutron supermirrors influenced by surface oil layers.

Neutron guides made of supermirror-coated glass are important components of most neutron scattering instruments, thus their quality and possible deterioration due to various deleterious effects (e.g., surface contamination or defects) deserve careful examination.

Direct observation of local distortion of a crystal lattice with picometer accuracy using atomic resolution neutron holography.

We demonstrate that neutron holography permits us to extend the determination of atomic positions beyond nearest neighbors at least up to the fourth neighboring shell around cadmium probe atoms alloyed into a lead crystal. The accuracy achieved is sufficient to allow quantitative determination of displacements of atoms due to elastic distortions induced by impurity atoms. The atomic positions derived from the holographic data are in good agreement with those expected theoretically due to Friedel oscillations in this system.

Holographic imaging of atoms using thermal neutrons.

In a recent paper [L. Cser, G. Krexner, and Gy.

Temperature and pH dependence of immunoglobulin G conformation.

Previous indirect observations have indicated that IgG may change its conformation at low or high pH and at a temperature of about 35 degrees C. By means of small angle neutron scattering a change in the value of the gyration radius of two different native IgG's was observed above 44 degrees C. No similar change was detected when the sample was previously dissolved in an acidic buffer.