What can you think of as the coldest place on Earth? If your answer is the depth of Antarctica, you are wrong. Nowhere on Earth is it colder than that, as impossible as it seems – in California of all places – or at least below it. Beneath Menlo Park in the Golden State, a three-mile-long machine is running in a tunnel that scientists are keeping cooler than some of the deepest reaches of space.Thank you for reading this post, don't forget to subscribe!
Keeping this small part of California at a temperature of -456 degrees Fahrenheit, about 3 degrees above absolute zero – the hypothetical temperature at which all nuclear motion ceases – is a major scientific achievement in itself. But the reason for this is really special. This temperature is maintained so that scientists at the Department of Energy’s SLAC National Accelerator Laboratory can operate the world’s most powerful X-ray laser, the Linac Coherent Light Source (LCLS) II, a new, improved version of the LCLS X-ray. Electron Laser (XFEL).
The LCLS-II laser produced its first high-energy radiation beams on September 12, 2023, and with that “first light” ushered in an exciting new era of X-ray-based research across a vast range of scientific fields.
Inside the LCLS-II tunnel, retrieved April 6, 2022.
Jim Gensheimer/SLAC National Accelerator Laboratory
At full power, LCLS-II will be capable of pumping out about one million X-ray pulses per second, which is about 8,000 times more than its predecessor, which was capable of producing about 120 X-ray pulses per second. This means that LCLS-II can produce an X-ray beam 10,000 times brighter than the previous version, making it the most powerful X-ray laser ever built.
“LCLS-II represents a fairly significant adjustment or paradigm shift for science,” said Greg Hayes, LCLS-II project director. popular mechanics, “The continuous train of X-ray pulses is quite attractive to scientists.”
As it turns out, “quite attractive” is an understatement. Thousands of researchers are already trying to conduct research with the experiment, but why exactly do scientists need such a powerful X-ray laser?
Over a period of 18 months, the original LCLS undulator system (left) was removed and replaced with two completely new systems that provide dramatic new capabilities (right).
Andy Freberg/Alberto Gamazo/SLAC National Accelerator Laboratory
Shooting molecular movies and advancing quantum physics
The key to LCLS-II’s unprecedented utility is its ability to produce so many high-energy light pulses per second and focus these on precise areas due to the short wavelength of the X-rays. This allows scientists to capture large-scale snapshots of reactions occurring at the atomic level one billionth of a millionth Of one second – femtosecond to attosecond. In fact, researchers using LSLC-II will create some of the smallest and shortest “movies” ever made.
LCLS-II will allow researchers to identify and record chemical events occurring on incredibly short time scales and create detailed “molecular movies.” For biology, this means being able to see the “messiness” of life – including processes like photosynthesis and protein action at a speed and scale that was not previously possible.
Thus, LCLS-II could potentially revolutionize scientists’ understanding of the mechanisms that make life possible, and on a practical level, this deeper study of biological molecules could lead to the development of new pharmaceuticals.
Staff scientist Meng Liang works on the Coherent X-ray Imaging instrument located in the LCLS Remote Experiment Hall.
Jacqueline Ramseyer Orrell/SLAC National Accelerator Laboratory
The timescales over which LCLS-II operates are also comparable to the timescales over which electrons move through complex systems carrying energy. Observing the flow of energy provides the opportunity to observe the internal structure of various materials on the atomic scale. This means that LCLS-II can help get to the heart of surprising materials like graphene that exhibit incredible and counter-intuitive properties derived from quantum physics and, as such, may form the backbone of future ultrafast quantum computers and secure quantum communications. Will become.
Other areas in which powerful X-ray lasers could be employed include creating more efficient energy-harvesting solar panels and even developing more useful and less harmful fertilizers.
Copper conical structure from inside the central cavity of the injector gun. The electron gun was assembled in a clean room at Lawrence Berkeley National Laboratory.
Marilyn Chung/Lawrence Berkeley National Laboratory
The LCLS-II electron gun and low energy beamline, built by Lawrence Berkeley National Laboratory, are lowered into the accelerator housing.
Don Harmer/SLAC National Accelerator Laboratory
“With it, we can now look at molecular interactions and take movies of chemical reactions and molecular combinations,” Hayes said. “This is a huge opportunity for scientists to be able to use a machine like this and look at chemical dynamics at that level.”
Aerial view of the SLAC cryoplant and the morning tailgate meeting.
Matt Beardsley/SLAC National Accelerator Laboratory
How does the world’s most powerful X-ray laser work?
To generate one million pulses of When introduced into a magnetic field, these electrons begin to oscillate; And when they do, they emit X-rays. What is special about LCLS-II and its predecessors is that these X-rays are emitted with similar wavelengths, making them ideal for studying matter on the atomic scale.
Waiting in the main control room for the first electrons to travel through LCLS-II, October 2022.
Olivier Bonin/SLAC National Accelerator Laboratory
LCLS-II is currently producing only “soft X-rays” with relatively low energies and long wavelengths. In the future, the upgrade means it will be able to generate “hard How to orient. Second and how it affects chemistry.
Generating one million pulses of Have to operate in comparison to space. And this is no small effort.
“The refrigerator we use to cool the machine is a liquid helium refrigerator, and that machine itself is an amazing piece of engineering,” Hayes said. “When the machine is completely switched off it consumes about 10 MW of power. This is the power required to keep the machine cooler than outer space, which is about four or five times the power used to accelerate the electron beam. By far, the largest power consumer of LCLS-II is the refrigerator itself.
Inside the LCLS cryoplant for cooling helium.
The vast range of science in which LCLS-II will play a role is astonishing, but such scientific progress comes at a price. In mere dollars and cents, the cost of the upgrade to LCLS was approximately $1.1 billion dollars. In terms of timing, Hayes said that planning for LCLS-II took approximately 12 years, with the project director investing a lot of his time in the project. But it has all been worth it, the machine is already living up to its potential.
“I have been working on the LCLS-II project since it began in 2011, and a significant portion of my life – about 25 percent – has been spent building this machine,” Hayes said. “I am incredibly surprised and gratified to know that this machine will be here for the next generation and for nearly 25 years… I look forward to seeing what impact LCLS-II will have on science and what impact it will have on science around the world.” “
Robert Lee is a freelance science journalist who focuses on space, astronomy and physics. Rob’s articles have been published newsweek, space, biology, Astronomy magazine and new scientists, He lives in the northwest of England with lots of cats and comic books.