Experimental Study of the Spectral and Correlation Characteristics of Low-Frequency Fluctuations in Tungsten Filaments

Low-frequency current fluctuations in tungsten filaments are experimentally studied in a frequency interval of 6 × 10 –5 –1 Hz. The experiments are carried out at heating temperatures of the filaments of 2250 and 2450 K. It is shown that visually different waveforms of the low-frequency (LF) noise are characterized by relatively similar power spectral densities represented as 1/ f γ , while the mean value of parameter γ ranges from 1.6 to 2.0. As distinct from the spectral characteristics, the autocorrelation functions are significantly more diverse. The correlation time, positive correlation time, and anticorrelation time of the LF fluctuations are numerically estimated.