Friday - September 1, 2023
13:30 - 17:00
All activities will be held in parallel, so it is not possible to participate in more than one activity.
REGISTER FOR ONLY ONE ACTIVITY! Please see description of all activities below.
Registration is open from Monday, August 21, 2023 - HERE.
Interferometric characterization of gas nozzles
The success of the E2 betatron and other gas-target experiments hinges crucially upon a precise understanding of the gas jet flow's density. To achieve this, optical probing emerges as a key methodology. This comprehensive session will introduce and elucidate both fundamental and advanced interferometric setups. Participants will engage in hands-on exploration, conducting measurements of a supersonic gas jet with a wavefront sensor. Through these experiments, participants will discern patterns concerning the gas jet's density variations in relation to the ambient and backing pressures. If time permits, an overview of the evolution from a single projection phase shift to density tomography will be provided, accompanied by insights into the specific engineering steps pivotal for executing tomography measurements.
THz generation in plasma by fs laser
The activity is focused on a generation of THz radiation (>5um wavelength) in two color laser plasma.
In the first step, the generation of second harmonic of fundamental beam needs to be properly set to get spatially and temporally overlaped two color laser beam with parallel polarizations.
Next the beam is focused by a parabolic mirror in the gas cell and beam is collected and colimated by second parabolic mirror and sent to michelson spectrometer.
The task of activity will consist of finding the correct conditions for second harmonic generation to get the two color beam generating THz radiation and then to measure the dependence of generated THz radiation on parameters of two color beam, e.g. polarization, wavelength of second harmonic, intensity and so on.
Fiber splicing workshop
During this activity, we would like to familiarize the trainee with knowledge and techniques utilized during fiber splicing.
Workshop will be divided into two parts: theoretical and practical.
Theoretical part is going to last 30-40min, and in this time, we will talk about:
- how optical fibers work and how are they manufactured,
- types of fibers and they applications,
- how does splicing work and why do we need to do this.
- Practical part will take place in optical laboratory. We will explain:
- how to distinguish between various fiber types (fiber scope),
- how to prepare fiber for splicing (stripping, cleaning, cleaving),
- splicing and testing the fiber,
- what happens when you try splicing different fiber types together.
Superfluid Helium nanodroplets at MAC user end-station
Superfluid He nanodroplets represent the ultimate molecular sample holder for spectroscopical studies of atoms, inorganic and organic molecules, clusters as well as large molecular aggregates placed in the cryogenic environment. In this hands-on activity you will be introduced to the MAC user end-station in the E1 experimental hall to which Helium nanodroplet machine is attached. You will learn how to produce ultracold Helium nanodroplets and how to dope them with different atoms or molecules; how to operate and align the He nanodroplet machine; how to tune the size of He nanodroplets and how to optimize doping conditions.
High-repetition rate solid targets for PW-class experiment
State-of-the-art PW lasers (as the L3-HAPLS laser) can now reach extremely high average power due to their unprecedented repetition rates of several Hz. This pushes the development of new solid targetry systems capable of delivering fresh samples at the same rate than the laser system.
This activity will present the system, how it is built and used. The participants will also learn how to measure and maintain an excellent shot-to-shot stability when manufacturing these devices.
Principles of time-resolved interferometry for laser driven shock propagation (VISAR)
The use of interferometry in science is very common to diagnose many properties. During the interaction of a ns-class high-power laser with matter, a shock is generated and propagates though the sample. Using a probe laser reflecting at the back the target, it is possible to measure the shock velocity and the pressures that were laser-driven. For this a Velocity Interferometer System for Any Reflector (VISAR) is used. The signal from the probe laser is sent into Mach-Zehnder interferometers and then to streak cameras giving access to time resolution at the few ps-level.
This activity will present the diagnostics, how it is built, aligned and used in the context of laboratory astrophysics / planetary interior science.
Simulations for High Harmonic Generation
The session consists of three parts. In the first part, the participants are introduced to a few important concepts regarding ultrafast pulses, such as the importance of the spectral width, and the effect of phase derivatives on the pulse. This introduction is aided by a Jupyter notebook, which calculates the spatio-temporal shape of a pulse with user-supplied phase derivative values via inverse Fourier synthesis. In the second part, a Single Active Electron model of HHG (the popular ‘Lewenstein SAE model’) is introduced (also in the form of a Jupyter notebook), and applied to calculate the HHG spectrum of selected isolated atoms - for example, He, Ne and Ar - under the effect of a laser pulse with certain peak intensity, wavelength and duration. The audience is invited to experiment with these parameters. In the third and most significant part, the audience is introduced to the Time-dependent Density Functional Theory (TDDFT), and - again, aided by a Jupyter notebook - are assisted with and invited to execute a TDDFT calculation using the Octopus code to obtain a HHG signal from an isolated atom. This result is compared with the result of the Lewenstein model using the same parameters, and with a published experimental result. The effects of the TDDFT parameters (both theory- and technical-related ones) is discussed, and the audience is invited to execute a higher quality simulation as a homework, which - if done right - reproduces the experimental result more closely. The expected result of this simulation is presented during the lecture.
!!! Please note that the students registered for this activity have to bring a laptop.
Steady state optical spectroscopy: absorption and emission
Participants will build (from scratch) a simple experimental setup to measure steady state absorption and emission spectra of the example sample (solution in cuvette). Participants will have opportunity to acquaint with basic optical and optomechanical components as well as with a modern miniature spectrometer. They will also learn simple optical alignment procedures. The obtained results will be compared with spectra measured by commercial devices (absorption spectrometer and spectrofluorometer).
Nonlinear optical processes: second harmonic generation and supercontinuum generation
Participants will learn about basic nonlinear optical processes generated by femtosecond laser pulses. In particular, they will study second harmonic generation, sum frequency generation and supercontinuum generation. They will build (from scratch) and align simple optical setups to generate and optimize efficiency of the studied nonlinear phenomena. They will also acquaint with basic laser beam diagnostics equipment such as modern miniature spectrometer and powermeters.
