[Show abstract][Hide abstract] ABSTRACT: A high-sensitivity (∼1 fT at a 100-s measurement time) self-generating magnetometer based on the optical orientation of cesium
atoms and intended for measurements of absolute values of weak (∼2 × 10−6 T) magnetic fields is described. Its distinctive feature is the complete optical isolation of the magnetic sensor from the
electronic units, allowing one to perform magnetic measurements under conditions of high electromagnetic noise. It is proposed
that the magnetometer be used as part of the multichannel system for stabilizing the neutron magnetic resonance in the search
for the electrical dipole moment of a neutron.
[Show abstract][Hide abstract] ABSTRACT: multichamber spectrometer intended for determining the electric dipole moment (EDM) of the neutron to within a projected accuracy of 10 –27 –10 –28 e cm  is in the stage of construction. One of the most important problems encountered in the creation of such instru-ments is to ensure stable neutron magnetic resonance conditions, since the essence of experiments in the search for the neutron EDM is to measure a shift of the magnetic resonance frequency of ultracold neutrons (UCNs) interacting with reversed electric field. Taking into account the smallness of the expected frequency shift, the stability of the resonance conditions must be on an extremely high level corresponding to magnetic field variations on the order of 10 –13 T over a period of 6 min (approximate duration of a single cycle of EDM measurements with UCNs retained in an electric field of reversed polarity). Only such conditions would pro-vide for the uncertainty of EDM determination not exceeding the statistical error . In order to suppress the influence of magnetic noise on the neutron resonance in EDM experiments, it is a common practice to use magnetic shielding of UCN chambers in combination with various experimental techniques [2, 3] for the monitoring of and correcting for residual variations of the average magnetic field act-ing upon UCNs. Since the increased requirements to the level of resonance stability are difficult to provide using only magnetic shields, it was decided to use the method of active stabilization of the neutron mag-netic resonance, which was originally proposed by
[Show abstract][Hide abstract] ABSTRACT: A silicon UCN detector with an area of and with a 6LiF converter was developed at PNPI. The spectral efficiency of the silicon UCN detector was measured by means of a gravitational spectrometer at ILL. The sandwich-type detector from two silicon plates with a 6LiF converter placed between them was also studied. Using this type of technology the UCN detector with analysis of polarization was developed and tested. The analyzing power of this detector assembly reaches up to 75% for the main part of UCN spectrum. This UCN detector with analysis of UCN polarization can be used in the new EDM spectrometer.
Nuclear Instruments and Methods in Physics Research Section A Accelerators Spectrometers Detectors and Associated Equipment 05/2005; 545(3):301-308. DOI:10.1016/j.nima.2005.01.317 · 1.22 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: An experiment aimed at measuring the neutron electric dipole moment by means of a magnetic resonance spectrometer and ultracold neutrons is described in detail, and results obtained in this experiment are presented. The value dn = (+2.6 ± 4.0 ± 1.6) × 10-28 e m is found. This result sets an upper limit on the neutron electric dipole moment at a 90% confidence level: |dn| < 9.7 × 10-28 e m.
Physics of Atomic Nuclei 07/1996; 59(7):1152-1170. · 0.51 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: A method of fast stabilization of the magnetic resonance in a magnetic resonance spectrometer has been developed and tested. The source of the oscillatory field is the synthesizer which frequency follows variations of the average magnetic field in spectrometer. To search for the neutron electric dipole moment in the experimental setup under unfavorable conditions in the reactor experimental hall a stability of the magnetic resonance has been achieved that is equivalent to a magnetic field stability at the level of ≈ 2.5 × 10−12 T per 6 min in a volume of about 501 with an electric field of 1.5 MV/m.
Nuclear Instruments and Methods in Physics Research Section A Accelerators Spectrometers Detectors and Associated Equipment 04/1995; 357(1):115-119. DOI:10.1016/0168-9002(94)01471-X · 1.22 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: A new experiment on the search for the electric dipole moment of the neutron was carried out using a magnetic resonance set-up with electric field and stored ultracold neutrons. The EDM of the neutron was measured to be +(2.6±4.2±1.6)×10−26e cm, the first error being RMS or statistical and the second one systematical. An upper limit at the 95% CL is |dn|<11×10−26ecm.
Physics Letters B 02/1992; 276(1-2-276):242-246. DOI:10.1016/0370-2693(92)90571-K · 6.13 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: A liquid hydrogen source of ultra-cold neutrons (UCN) developed for an experimental search for the electric dipole moment of the neutron is described. The results of an investigation of the yield of UCN from gaseous, liquid, and solid hydrogen as a function of temperature are presented. The UCN counting rate obtained at the output of the 6 × 7 cm2 neutron guide tube is 5 × 104 n/s. This counting rate corresponds to a flux of neutrons whose velocity along the axis of the neutron guide tube is below 7 m/s. Preliminary measurements of the UCN yield from liquid and solid deuterium have been carried out.
Physics Letters A 12/1980; 80(5-6):413-416. DOI:10.1016/0375-9601(80)90784-7 · 1.68 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The results of measurements of the electric dipole moment (EDM) of the neutron using ultra-cold neutrons (UCN) are presented. A description is given of the source of UCN devised, and of a magnetic resonance spectrometer confining UCN for ≈ 5 s. The use of a double-chamber spectrometer and a system for double analysis of polarization enabled us to eliminate most of the systematic errors possible.The measurements resulted in the EDM d=(4±7.5) × 10−25e · cm. From this it is inferred that at the confidence level of 90%.
Nuclear Physics A 06/1980; 341(2-341):269-283. DOI:10.1016/0375-9474(80)90313-9 · 2.20 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The result of measuring the electric dipole moment (EDM) of the neutron by using ultracold neutrons is presented. The results of the measurements give the value of the EDM: d/sub n/4=(plus-or-minus7.5) x 10/sup -25/ excm. Hence, it can be concluded that vertical-bardvertical-bar<1.6 x 10/sup -24/ excm at the 90% confidence level.