Leader: Daniyar Berikov

Work phone number: +7 (496) 216-36-83

Work E-mail:  This email address is being protected from spambots. You need JavaScript enabled to view it. 

Scientific problem:

The main challenge is understanding the origin and consequences of the ROT-effect in the angular distribution of prompt fission gamma rays. Key unknowns include:
Spin generation mechanism: How does the internal dynamics of the fissile nucleus, especially near the critical scission point, produce fragment spin that is preferentially aligned perpendicular to the fission axis? The use of polarized neutrons is crucial here, as it provides a fixed spatial direction allowing to reveal these subtle spin and angular momentum effects that would otherwise be hidden.

Objective: 

The purpose is to build a new setup at the IBR-2 reactor to study the ROT-effect in the binary fission. Using thick, opaque targets, we will test a novel method to reconstruct fragment trajectories by analyzing prompt neutron emissions. This approach will accelerate data collection, enabling detailed study of this subtle effect to illuminate fragment deformation and rotation.

Tasks:

 1. Design, implementation and calibration of the new experimental facility, including detectors for both prompt gamma-rays and prompt neutrons.
2. Implementation of fission experiments with thick, opaque targets, measuring the angular distributions of both prompt gamma-rays and prompt neutrons simultaneously.
3. Development and validation of the novel methodology for reconstructing fission fragment trajectories by analyzing the measured angular anisotropy of the prompt neutrons.
4. Analysis of the correlated data to quantify the ROT-effect.
5. Preparation and submission of results for publication and reports.

Research facilities: 

The paper will be completed under the project “Investigations of neutron nuclear interactions and properties of the neutron” at the beamline 1 of IBR-2.