• Study of the optical spectrum of hydrogen-like systems using the sodium atom as an example;
• Experimental determination of wavelengths of sodium spectrum lines;
• Observation of the yellow sodium line as a doublet (separately recorded lines with wavelengths of 589.0 nm and 589.6 nm).

The laboratory setup consists of a spectrometer, a sodium lamp with a power supply, and a collimator. The spectrometer is based on a diffraction grating and a CCD matrix located at the focus of the mirror behind the diffraction grating. The spectrometer resolution is 5 nm. A special computer program is used to control the spectrometer and read information about the spectral composition of the analyzed radiation. The sensitivity of the spectrometer is also adjusted in the computer program that works with it by measuring the time of exposure of the CCD matrix to radiation.

The data are presented on the computer screen in the form of a spectrum - the dependence of the radiation intensity on the wavelength. The tasks of the laboratory work include recording the strongest lines - the yellow sodium doublet (a short data accumulation time is set in the program) and measuring the position of the remaining lines (the data accumulation time is increased by 30-40 times). In both cases, the dark spectrum is subtracted (the spectrum recorded without turning on the sodium lamp). The wavelengths of all the obtained lines are compared with the tabular data.