Vladimir Lenok

Research Groups

Biography

I graduated as a engineer-physicist in the realm of solid-state physics and photonics. My diploma work was devoted to a study of radiation defects in silicon with the injection current method.

After graduating from the university, I started to work as a research assistant in the project of an imaging air-Cherenkov telescope for the Tunka Advanced Instrument for cosmic ray physics and Gamma Astronomy (TAIGA) located in Siberia. My goal was design of the optical system of the telescope in close cooperation with engineers, which also included assessment of the preliminary optical system design for the air-shower observations, and performed its further optimizations to the requirements of the observatory: the observatory location, a new wide-field-of-view camera, desired operation energy threshold, etc. To achieve this goal a special software had to be created. Since the state-of-the-art pieces of software of those time did not provide us sufficient amount of flexibility, I developed a new piece of optical ray-tracing software that met the project’s requirements. The developed software was validated against the commercial optical software Zemax. The developed ray-tracer was used throughout the design process and later for simulating the telescope optics, components of the camera-supporting truss, and camera operation as the instrumental response in large-scale air-shower simulation libraries.

In parallel to working in the Cherenkov telescope project for the TAIGA Observatory I worked in the industry as a flight-dynamic engineer. This work in an engineering and enterprise environment allowed me to apply my education in physics to concrete pieces of engineering in the context of mathematical modeling of their performance. My task was a flight-dynamic characterization of a training aircraft. Working on this problem in close cooperation with aerodynamic engineers, I developed a mathematical model of the aircraft dynamics and corresponding software for performing calculations. The experience that I gained in the industry is valuable to me today. However, I decided to focus on science.

My doctoral work is related to the radio detection of cosmic-ray air showers with sparse radio-antenna arrays. Namely, I am developing a new method for modeling detection efficiency, which can be applied to any air-shower radio array. As an example instrument, I use the Tunka-Rex array located close to Lake Baikal. My goal was to create a model that would describe the complex picture of the efficiency distribution without the usage of the Monte Carlo simulations for the whole array in its various configurations. The central idea of the the model that is under development at the moment is to exploit known statistical properties of the detection process and turn them into estimating the instrumental detection efficiency.

The approach chosen for the efficiency model has already brought an astrophysical outcome. An early version of this model was used to estimate the cosmic-ray energy spectrum observed by the Tunka-Rex array, for the time being, making it the only radio antenna array that achieved the performance level sufficient for this task. The results on the Tunka-Rex estimation of the energy spectrum are openly available via the KCDC web-service (kcdc.ikp.kit.edu/spectra).

Another aspect of my doctoral work is related to the Auger Engineering Radio Array data analysis at the Pierre Auger Observatory. At the beginning of my work, I evaluated various antennas types for the Auger detector upgrade's potential radio component. My analysis's findings resulted in the approval of SALLA as an antenna for use in the detector upgrade design. Presently, I am involved in collaborative work is investigating the possible biases of the absolute energy scale in the measurements by the AERA instrument.