X-ray speckle visibility spectroscopy (XSVS) extends X-ray Photon Correlation Spectroscopy (XPCS) to the study of ultrafast dynamics (fs-ns range) beyond current XPCS limitations. One XSVS method is to generate pulse pairs (twin pulses) separated by a specific and tuneable time delay t. Recording radiation scattered from a sample illuminated by twin pulses allows to determine whether the sample is static or there are structural changes happening over t. XSVS is based on an analysis of the speckle contrast originating from illumination of the sample by a coherent X-ray beam.

XFELs are ideal sources to generate such ultrashort pulse pairs and we will explore two methods: 1) using a crystal-based split-and-delay line (SDL) and 2) generating the twin-pulses using the linac, beyond the 4.5 MHz rate available today as a standard. Nanosecond dynamics of nanometre sized objects in aqueous solutions will be targeted to demonstrate the uniqueness of the method. Applications to nanoparticle diffusion, complex fluids, and supersaturated solutions are foreseen.  
         
The project is partially funded by the Cluster of Excellence “BlueMat: Water-Driven Materials” which is a new research initiatives managed by the Technical University of Hamburg-Harburg (TUHH, AG Prof. Dr. Patrick Huber) and where EuXFEL is a collaborator. The successful candidate will integrate into the MID team at EuXFEL but will also connect with BlueMat partners and interdisciplinary teams that combine science, sustainability, and technology.

The PhD project is organized over workpackages:
 WP-1: exploration of twin pulses created by the accelerator. 
 WP-2: exploration of twin pulses created by the SDL
 WP-3: benchmarking experiment based on diffusion of nanoparticles in water
 WP-4: structure and dynamics of supersaturated solutions

This project aims to push XSVS as a novel X-ray scattering technique for dynamics of Blue Materials. There is synergy with other BlueMat cross-area imaging projects and close coordination and collaboration are anticipated within the Excellence Cluster.     ​​​​​​

The tasks for this position are therefore:

• Participate in commissioning experiments of the upgraded X-ray split-delay line (SDL) at MID
• Participate in research projects associated with measuring dynamics using the x-ray speckle visibility spectroscopy (XSVS) technique provided by the SDL and the linac
• Working together with BlueMat partners and interdisciplinary teams
• Complete and defend doctoral thesis

• Master degree in physics or a related science field
• Interest in data analysis and hands-on work with advanced instrumentation
• Flair for experimental work
• Interest and ability to work and collaborate in an international setting (command of English is required) 
• Experience with programming and data analysis in python is an advantage
• Knowledge of condensed matter physics, optics, and X-ray science are assets

Become part of a vibrant international and multi-cultural team of scientists, engineers, technical and administrative staff. Be involved in cutting edge scientific and technical progress and participate in our international networks. Experience our atmosphere of tolerance and respect.

Salary and benefits are similar to those of public service organizations in Germany, this includes for example:

• family friendly working environment (e.g. additional childcare days)
• flexible working times and option for work from home depending on tasks
• 30 days of vacation, 24th and 31st of December are free as a courtesy of the employer 
• extensive relocation benefits 
• generous company pension scheme (6,45% of monthly salary)
• monthly social events and subsidized company restaurant 
• partially financed job-tickets for public transportation
• extensive training opportunities incl. subsidized English and German language classes
• Easy and free access to a mental health platform to support your wellbeing

Our company language is English.

Please provide your CV and a motivation letter in English as well as any reference letters.

The European XFEL GmbH is an equal opportunity and affirmative action employer and we promote and support diverse and heterogenous teams. Applicants with disabilities will be given preference over other equally qualified applicants.