Minutes of the Project coordinators meeting on June 4, 2019 (DRAFT 1) 1. Part A. [Agenda item #1] - Part 1: Presentation of BLiX by Dr. Stiel Dr. Stiel described the setup of the BLiX laboratory. The laboratory has two soft X-ray plasma source, based respectively on a liquid nitrogen jet and solid copper targets. The sources are driven by two laser systems: a "40 Watt" think-disk system from TRUMPF (250 micro-Joule, 0.5-30 ns, 1030 nm, 100/200 Hz) and a 130 Watt slab laser system (0.4-1 ns, 1.3 kHz, 1064 nm). The liquid-nitrogen source has 10^-2 - 10^-3 conversion efficiency. Dr. Stiel then described examples of BLiX beamline applications, including imaging of frozen yeast cells and tomography of diatom algae. Tomography requires 1 minute per projection. These activities are a part of the CRC 1340 collaboration "In-vivo visualization of extra-cellular matrix pathology" Another example involves pump-probe NEXAFS spectroscopy, using reflection zone plates. The experiments were performed on Ti and Ni L-edges, Mg K-edge, and lanthanide M-edge features. Current activities of the BLiX laboratory include: - Optimization of sample preparation (evaporation, spin-coating) - Commissioning of large-aperture fluid cell for NEXAFS - New RZP (sp?) structure - Fast SCMOS detectors for NEXAFS - NEXAFS pump-probe spectroscopy (ns to ms). This is a collaboration with MPI for chemical energy conversion. A few questions were raised after the presentation: Prof. Eisebitt asked about the causes of the low 3D resolution as compared with the 2D, wobble, missing edge, depth of field problems? Prof. Elsaesser asked about how much of the solid angle is collected by the X-Ray optics? Dr. Stiel answers that 10^-2 collection angles, reflectivity 5%. Both parameters could be improved further. Prof. Eisebitt asked what is the distance between the target and the optics? Answer: 20 cm from target. Prof. Elsaesser asked whether there are plans to use something else than liquid nitrogen with the liquid jet technology? Dr. Stiel answers that yes, water, ethanol, methanol, can be used depending on applications. The choice of liquid nitrogen is optimal for work in the water window. Dr. Nagy asks why such high purity of liquid nitrogen is required? Dr. Stiel answers that water contamination would lead to ice formation at the tip, blocking the liquid jet. - Part 2: Presentation of EFRE-Nanomovie by Dr. Schnürer Dr. Schnürer described the setup and activities of EFRE-Nanomovie project. The project investigates feasibility of HHG sources in the water window and beyond. One of the intended targets is transient absorption of metal-ligand complexes in solution (Dr. Erik Nibbering), which requires detection of the optical-density changes at the 1-percent level. These measurement rely on resonant inelastic soft-X-ray scattering (RISXS); achieving 1% OD sensitivity requires a minimum of 10^5 photons. Dr. Schnürer gave an overview of the project development. The key milestones are the implementation of the phase-II beamline in collaboration with HZB (2019). The next key milestone is phase-III (2020). The project relies on a 2-micrometer laser system. The pump laser is Dira-500 (TRUMPF). The laser running close to spec, with some problems. The pulse stability is approximately 0.5%. For the front-end, stability and CEP remain a problem, and are being worked on. The site-acceptance test of the system did not pass so far. The laser system produces up to 20W at 2 micrometers with the 400W, 1-micrometer pump. Some beam profile degradation is observed. The immediate plan for future work is to look at HHG in a gas cell. The target can be switched to a fiber if this proves necessary. The second laser system (supplied by Fastlight) is under development. This system will produce light in the 2.7-3.7 micrometer range. After the presentation: Dr. Rouzee asked what are the parameters for the 2- and 3-micron sources? Dr. Schnürer answers that simulations suggest conversion efficiency of 10%, giving power of 40W or above. For the pulse duration, the bandwidth is sufficient to support few-cycle pulse. However, the pulse has hight-order chirp, which not easy to compensate. At the moment, the pulse duration is 30 fs. Prof. Elsaesser asks that, if the first steps of the planned setup are fulfilled, what would be the proof of principle experiment? Dr. Schnürer answers that the most likely first target is nitrogen K-edge, using samples from Dr. Nibbering. Dr. Rouzee asks about the design of the beam lines? Dr. Schnürer answers that he is in discussion with the colleagues of HZB, to see which reflective optics are needed for certain energy ranges. This is an ongoing process, that was just recently started. Prof. Eisebitt comments that two beamlines are planned. One beamline will be for Transient absorption experiments and the other for monochromatic beam work. Dr. Rouzee comments that, in this setup, there will likely be less than one photon per pulse, so measurements would have to be averaged. Prof. Eisebitt agrees. 2. Part B. [Agenda item #2] Other items. - Item 2.1 Prof. Eisebitt introduces the newly-elected PhD student representative (Mr. Thomas Kalousdian). In the future, PhD student representatives (Mr. Kalousdian and Ms. Gerlinger) will attend project coordinator meetings. Mr. Kalousdian introduces himself and comments that the other representative is Ms. Kathinka Gerlinger. Dr. Patchkovskii asks if they are already included in the project coordinators email list, otherwise he will make sure they are, so they can get emails about the project coordinator meetings. - Item 2.2 Dr. Nagy asks about the status of the decision of the renewal of software licenses, that now is paid directly by each division's budget, and what happens with volume licenses if he wants to get rid of some. A discussion follows in which is concluded that he should contact Dr. Kruel to show the updated state of the licenses, and estimate the cost of dropping some volume licenses. - Item 2,3 Dr. Rouzee asks if we could hold the project coordinator meetings always on Fridays at 10 am, as, for example, today was overlap with project 2.1/2.2 seminar. Dr. Patchkovskii replies that due to the busy schedule of the directors, it is quite difficult to find an acceptable time slot for the coordinators meeting. When the usual time slot (the last Friday of the month at 10:00) is not acceptable (which happens more often than not), he tries to avoid scheduling conflicts with events announced in the institute's online event calendar. This time, the 2.1/2.2 seminar was not announced when he arranged for dates for the current meeting. Dr. Patchkovskii apologizes for the inconvenience this caused. --------------- Dr. Patchkovskii asks, that, given that we approach the conference/holiday season, if it is worth to try to have another project coordinator meeting before the summer break? Prof. Elsaesser replies that teaching ends 15 of July, and we should try to have another meeting before the Symposium at the end of August. Minutes prepared by F. Morales and S. Patchkovskii on June 6, 2019, with corrections from August 6th