Some Results of Photometric Measurements of Ionospheric Artificial Airglow at 557.7 and 630 nm Lines of Atomic Oxygen Caused by High-Frequency Radio Emission of the SURA Facility during Development of Sporadic E Layer

The results of analysis of the experimental data collected on 5 September 2021 on 557.7 and 630 nm artificial airglow of the ionosphere induced by powerful HF radio waves at the SURA facility are presented. For optical measurements, a photometric suite located directly next to the SURA facility was used. Fast variations in the atmospheric emission intensity at 557.7 nm, 630 nm, and 391.4 nm with a three-channel photometer and spatial–temporal variations in the 557.7 nm with a CCD camera were measured. An ionospherically reflected pump wave and the stimulated electromagnetic emission (SEE) were recorded. Background ionospheric conditions were registered with ionosonde. For the first time, an increase in the 557.7 nm emission intensity induced by the SURA facility radiation was found concurrently with a partial blocking ionosphere in the F-region and suppression HF-induced phenomena in the F-region (the 630 nm airglow increase and SEE generation, powerful radio wave anomalous absorption) during the sporadic E-layer (Es) development. Additionally, we managed to obtain images showing moving spots of the SURA-induced 557.7 nm emission increased intensity at the Es layer heights

HF-Induced Modifications of the Electron Density Profile in the Earth’s Ionosphere Using the Pump Frequencies near the Fourth Electron Gyroharmonic

We discuss results on plasma density profile modifications in the F-region ionosphere that are caused by HF heating with the frequency f0 in the range [(−150 kHz)–(+75 kHz)] around the fourth electron gyroharmonic 4fc. The experiments were conducted at the HAARP facility in June 2014. A multi-frequency Doppler sounder (MDS), which measures the phase and amplitude of reflected sounding radio waves, complemented by the observations of the stimulated electromagnetic emission (SEE) were used for the diagnostics of the plasma perturbations. We detected noticeable plasma expulsion from the reflection region of the pumping wave and from the upper hybrid region, where the expulsion from the latter was strongly suppressed for f0 ≈ 4fc. The plasma expulsion from the upper hybrid region was accompanied by the sounding wave’s anomalous absorption (AA) slower development for f0 ≈ 4fc. Furthermore, slower development and weaker expulsion were detected for the height region between the pump wave reflection and upper hybrid altitudes. The combined MDS and SEE allowed for establishing an interconnection between different manifestations of the HF-induced ionospheric turbulence and determining the altitude of the most effective pump wave energy input to ionospheric plasma by using the dependence on the offset between f0 and 4fc

Measurement of analysing powers for neutron scattering on CH2, CH, C and Cu target for momenta from 3.0 to 4.2 GeV/c

During two beam runs in the years 2016 and 2017, the analyzing powers (Ay) for protons and neutrons scattering on CH2, CH, C and Cu targets were measured at the nucleon momentum from 3.0 to 4.2 GeV/c with the ALPOM2 setup at the Nuclotron accelerator. The data for polarized neutron beam are obtained for the first time, thanks to the unique polarized deuteron beam that is presently available up to 13 GeV/c. Earlier, analyzing powers for polarized neutrons had been measured only for thin hydrogen targets. Cross sections and analyzing powers for np, for both elastic scattering and charge exchange are known up to 29 GeV/c. No data existed for thick analyzers. The measurement of the angular dependence of Ay for the neutron is essential to the continuation of the neutron form factor measurements to the highest possible transferred momentum-Q2 at the Jefferson Laboratory. The reaction p+Cu(W), with the detection of a neutron in the forward direction by a hadron calorimeter, can be used for the measurement of the proton polarization at the future NICA collider