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PETRA IV prestudy

There are plans to upgrade the PETRA synchrotron to PETRA IV. A prestudy is ongoing to assess the impact of the planned upgrade on the Swedish Materials Science beamline - including the opportunity for a state-of-the-art X-ray microscopy instrument for experiments at the nano scale in bulk materials and devices.


DESY has an ongoing planning project, PIV, to upgrade the PETRA III synchrotron to its 4th generation.

CeXS therefore also has ongoing dialogues with DESY to assess the impact and opportunities for the Swedish Materials Science beamline.

Current timeline

DESY’s current target milestones are:

  • Sept 23. Deadline for the proposal to the German authorities for funding the upgrade
  • 31 Dec 26 to 31 Dec 28. Planned shutdown period
  • 1 Jan 29. PETRA IV goes live with the first trench of beamlines available for use

Note. DESY's plans are dynamic because the PETRA IV upgrade project requires noteworthy financing, involves many actors and is technically complex.  

Ambitions for PETRA IV

The ambition is that PETRA IV will be the world's most brilliant X-ray source.

Brilliance is a measure of the directionality and intensity of an X-ray beam. Intensity is important because it determines whether a signal can be obtained, or not. Intensity also influences the maximum temporal measurement frequency. Directionality (coherence) is important because it determines the focal size of the beam and thereby the scales of the phenomenon that can be measured. Directionality (coherence) also influences measurement repeatability.

The PETRA IV design has been elaborated by DESY in this Conceptual Design Report .  

A key element of the design is multi-bend achromat technology, which was pioneered by MAX IV (and subsequently implemented in SIRIUS and ESRF). Multi-bend achromat technology, together with the PETRA synchrotron's large circumference, ought to produce X-rays that have a brilliance that is more than 1000 times PETRA III's current high-energy X-rays - with an ability to focus down to the nanometer scale.

DESY is therefore promoting PETRA IV as "the ultimate 3D microscope". Measuring length scales as low as Å scales, as well as being able to dynamically scale up to mm scales, is important to make scientific breakthroughs in many fields.

Comparison of the characteristics of the PETRA III beam with the design plans for the PETRA IV beam.

Impact on the Swedish Materials Science beamline

Technically, since the Swedish Materials Science beamline is a new, state-of-the-art instrument, it’s components can be simply refurbished and optics upgraded to take into account the PETRA IV beamline's characteristics. Thus, existing Swedish investments will be sustained.  

This straightforward refurbishment also means that DESY currently plans for the Swedish Materials Science beamline to be amongst the first trench of beamlines to go live on 1 January 29.  

When the PETRA IV Swedish Materials Science beamline opens, researchers will be able to measure deeper within materials, capture information down to smaller scales as well as capture data with higher temporal frequencies.

Responsible: DESY in liaison with CeXS.

New opportunity for nano-scale measurements

The Swedish Materials Science community may also gain a novel experimental opportunity.

The background to this novel opportunity arose when DESY asked the user community for Scientific Instrument Proposals (SiPs) for PETRA IV. CeXS orchestrated 3 proposals and led one of them. The review of our SIP3 received the highest evaluation of all the 189 SiPs that were proposed.

SiP3 proposes high energy x-ray microscopy capabilities for experiments at the nano scale in bulk materials and devices. The instrument design concept is Bragg Coherent Diffraction Imaging (BCDI). A BCDI instrument design with the PETRA IV beamline's coherence will significantly improve the spatial resolution of measurements compared to existing instruments elsewhere. Thus, materials experiments at the nano scale in bulk materials and devices will become possible - also with a high temporal resolution of the nano scale experimental data.

The temporal and spatial resolution of the BCDI and other instruments is illustrated below.

Illustration of the spatial resolution of various instrument techniques
Illustration curtesy of Professor H.F. Poulsen

A prestudy is ongoing to refine this concept into a beamline design, with associated science cases.

The CeXS Director, Peter Hedström, is leading the prestudy into this state-of-the-art option, with the prestudy engaging the Swedish research community, the SMS beamline staff, and researchers around the world.

Responsible: CeXS Director Peter Hedström