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Polish scientists use X-ray technology to measure chemical reactions

At the heart of chemistry and biology is a phenomenon that lasts trillionths of a second. They are everywhere. Until recently, the world began to try to record their true path, with mixed results. However, Krakow scientists have proved that they can build a new window into the field of Arab physics and draw a promising blueprint.


  

Attosecond phenomena can be studied with free electron lasers such as swissfel (this photo shows its research station alvra). X-ray timing technology can provide the most accurate image of these phenomena by analyzing the shape before and after the interaction between laser pulse and sample. Source:IFJ pan/Paul Scherrer Institute/swissfel alvra

Chemical processes involving changes in the arrangement of electrons in atoms and molecules take place quickly, both deep in cells and in test tubes. Their frequency and importance are in line with the interests of scientists who have long tried to track their evolution over time.

The current X-ray technology aims to observe the process lasting attosecond (trillionth of a second), which puts forward great requirements for the characteristics of the radiation beam used.

According to a new measurement method proposed by a group of scientists at the Institute of Nuclear Physics (IFJ pan) of the Polish Academy of Sciences in Krakow, this situation is expected to improve in the next few years.

The X-ray free electron laser (xfel) makes it possible to track the progress of the process as fast as the combination of atoms and molecules. Due to their size and construction cost, these equipment are used only in a few places around the world. They produce ultrashort X-ray pulses that last only a few femtoseconds.

Two main measurement methods used in xfel Laser CenteryesX-ray spectrum and X-ray diffraction。 The former studies the change of radiation spectrum when interacting with the sample, while the latter studies how X-rays scatter on the sample.

  这两种方法都有相似的缺点:它们不可能看到比脉冲持续时间短的过程。这就yes为什么在汉堡附近使用欧洲XFEL激光器时,迄今为止最快的过程持续了5飞秒。


  几飞秒并不yes很长,但这仍然不yes阿物理学的世界。为了做到这一点,我们转向了计时技术,即一种分析脉冲如何随时间改变形状的技术。我们从理论上证明,这种方法可以成功地用于超短X射线脉冲,以获得与样品相互作用前后脉冲形状变化的信息。

– Dr. Wojciech blachucki, first author, Institute of physical chemistry, Polish Academy of Sciences


  本文证明了测量超短激光脉冲的时间结构,即获取脉冲形状信息yes可行的。即使在XFELs技术发展的当前阶段,该技术也能够从阿物理学领域推断现象。

If the laser pulse lasts 20 femtoseconds and the information about its time structure can be reconstructed within 100 points, it can be envisaged to detect the phenomenon that occurs at the time of 20/100=1/5 femtosecond (i.e. 200 attosecond).

  值得注意的yes,目前时间分辨率可能小于1飞秒,但激光束的强度必须大大降低。这种技术有一系列负面后果。

The time required to irradiate the sample increased to several hours, which made the actual experiment difficult. This limitation does not exist in the X-ray TDOA meter. It eliminates the need for radiation pulses by using a sensitive method to determine the time structure of radiation pulses.

After putting into useThe existing laser center may spend part of its working time on attosecond measurement of other tissues (such as industry).

  尽管如此,X射线测时术成为一种典型的研究方法还需要几年时间。证明与样品相互作用前后激光脉冲的平均持续时间不同,将yes实现该技术的第一步。

  这将yes对基于克拉科夫的物理学家技术准确性的实验验证。研究人员只会在后期阶段更详细地重建与材料接触前后的脉冲时间结构。


 The measurement technology we proposed is not only limited to free electron lasers, but also universal. Therefore, it can also be successfully used in other light sources that generate ultrashort X-ray pulses, such as the aurora infrastructure near Prague.

– Dr. Jakub szlachetko, Institute of physical chemistry, Polish Academy of Sciences


Scientists from Stockholm (KTH Royal Institute of Technology), Uppsala (Uppsala University), villigan (Paul Scheler Institute), schenefeld (European xfel Co., Ltd.) and Warsaw (IFJ pan, Institute of physical chemistry, Polish Academy of Sciences) have contributed to the research of IFJ pan. The study was funded by the Polish National Science Center.

Journal Reference:B ł achucki. W., et al., (2022) Approaching the Attosecond Frontier of Dynamics in Matter with the Concept of X-ray Chronoscopy. Applied Sciences. doi. org/10.3390/app12031721.