The experimental complex KOLKHIDA operating on the 1st beam of the IBR-2 reactor. It consists of a polarized neutron spectrometer and a polarized nuclear target installation.

 

1 – primary collimator; 2 – Soller collimator; 3 – polarizer crystal; 4 – guiding field electromagnets; 5 –  Mezei flipper; 6 – shim; 7 – cryostat; 8 – analyzer crystal; 9 – detector.

The flight distance from the moderator in the reactor radiation zone to the detector is 15.9 m and comprises the following distances: moderator - polarizer, 12.4 m; polarizer - analyzer, 2.5 m; and analyzer - detector, 1.0 m.

 

Instrument details

The Co (92%)-Fe (8%) single crystals are used for neutron polarization and polarization analysis. The thickness of these crystals is 3 mm and the surface areas are 34x34 mm2 and 35x53 mm2 correspondingly. These crystals are placed between the poles of the electromagnets which produce a magnetic field of H=0.4T. The spectrometer is assembled on a massive arm. It comprises the guide field magnets (4), the flipper (5) for polarization reversal, the polarized target position (7), the polarization analyzer (2) with its magnet and the platform with the neutron detector (8). Supported by a circular rail, the arm can be rotated about the same axis as the neutron polarizer. The rotation axis of the detector platform coincides with the axis of the neutron analyzer. A 3He counter is used as neutron detector and a 235U fission chamber (6) is used to monitor the primary neutron beam. The control module based on a PC with 166 MHz Pentium processor and CAMAC control units are used to control the installation, rotate all its assemblies, measure their positions and also to obtain time-of-flight spectra of neutrons. Planned neutron polarization is 98%.

 

Main Parameters

Angle θ (degree) 19 12 6 4 3
Wavelength λ (E) 1.15 0.75 0.37 0.25 0.19
Energy En (eV) 0.062 0.15 0.60 1.3 2.3
Counting rate of the detector after polarizer, n1 (sec-1) 800 270 65 33 22
Intensity of polarized neutrons I1(n/sec cm2) 430 23 3.1 0.6 0.2
Counting rate of the detector after analysis n2 (sec-1) 70 23 3.1 0.6 0.2

 

The neutron polarization  Pn≈ 0.98, energy resolution 10-2.

Instrument Responsible:
Tsulaya Murman
Russia, Moscow reg., Dubna, Joliot-Curie str., 6
tel. +7 (49621) 6-37-83
e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.

 

Main research fields:

1. Investigation of nuclear neutron precession.

2. Investigation of magnetic structure.

 

3He-4He refrigerator with superconducting solenoid

Dilution bath temperature is T=23mK at 3Не circulation rate n= 1. 10-3 mole/s.

Magnetic field strength is Н = 6 T

Magnetic field homogeneity is ∆Н/H = 2.4 x 10-4

 

1 - main flange;

2 - vacuum housing;

3 - central 3He pump-out pipe;

4 - nitrogen bath;

5 - nitrogen screen;

6 - helium bath;

7 - helium screen;

8 - helium bath to be evacuated;

9 - dilution stage helium screen;

10 - cryo-valve;

11 - superconducting solenoid;

12 - nitrogen trap of booster pump NVBM-2.5;

13 - oil filter;

14 - pump NVG-2;

15 - carbon trap;

16 - 3He storage cylinder;

17 - 3Не - 4Не mixture storage cylinder;

18 - evaporation bath;

19 - heat exchangers;

20 - dilution bath.

 

Publications

  • Y.G. Abov, V.P. Alfimenkov, M.Tsulaia et ai., IET(transl. PTE), 3, 2000, p. M.I. Tsulaia, V.M. Tsulaia, V.P. Alfimenkov, 3He-4He Dulition Kriostat for Investigation of Iteractions of Neutrons with Polarized Nuklei – Bulletin of the Georg. Nat.Acad. of Scien., v.2, 4, 2009.
  • M.I. Tsulaia, V.M. Tsulaia, V.P. Alfimenkov, 3He-4He Dulition Kriostat for Investigation of Iteractions of Neutrons with Polarized Nuklei – Bulletin of the Georg. Nat.Acad. of Scien., v.2, 4, 2009.
  • Yu.G. Abov, V.P. Alfimenkov, L. Lason, Yu.D. Mareev, L.B. Pikelner, V.M. Tsulaia, M.I. Tsulaia, I.M. Salamatin, Kolokhida Instrument for Experimental Investigations of Interactions of Polarized Neutrons with Polarized Nuclei – Nuclear Instruments and Methods in Physics Research, A, v. 601, i.3, 4, 2009, p. 317-325