Vacuum Technology: In April 2020, astrophysicists at the University of Chicago witnessed what they called an exceptional event: the collision of two black holes of significantly different masses. The significance of this event was its impact on astrophysics and the physics of gravity. In short, it gave astronomers insight into how black holes rotate, as well as experimental evidence for the existence of gravitational waves, predicted by Albert Einstein’s theory of general relativity but never observed.
Enabling the discovery of black holes
How did they do this? The fundamental experiments underlying this science require complex machines that operate in the most demanding vacuum conditions. In fact, “vacuum” technology is at the forefront of almost all high-energy physics, particle acceleration, and surface science.
Vacuum can be described as “a space in which the pressure is less than the surrounding atmospheric pressure.” Vacuum science is a topic and concept that has stimulated many brilliant minds for thousands of years.
The origins of vacuum science date back to the 4th century, when Aristotle declared that “nature abhors a vacuum.” The highest level of vacuum achievable on Earth, called ultra-high vacuum (UHV), is obtained using a device called an “ion pump”: All major innovations in ion pump technology have evolved since the invention of the ion spray pump in 1957 by Varian Vacuum (now Agilent Vacuum) and ConFlat Flange (CFF), which ushered in the UHV era. Today, vacuum solutions power university and government laboratories and major physics projects around the world.
Gravitational waves
A gravitational wave is an invisible wave in space. It moves at the speed of light (300,000 km per second) and stretches and compresses everything in its path. As part of Einstein’s theory of relativity, he predicted that a single event occurs when two bodies, such as a planet or star, orbit each other.
He hypothesized that this type of motion could cause waves in space, which would spread out like ripples in a pond. Scientists call these waves in space gravitational waves.
The most powerful gravitational waves are created when objects move at very high speeds. Examples of events that can cause a gravitational wave include the asymmetric explosion of a star (supernova), the orbit of two large stars, or the merger of two black holes.
In 2015, scientists detected gravitational waves for the first time. They did so with a highly sensitive instrument called LIGO (Laser Interferometry Gravitational-Wave Observatory). What they discovered was that, even though it was only detected in 2015, the collision happened 1.3 billion years ago.
Getting a closer look
Strategically nestled atop Cerro Pachón in Chile is the Large Synoptic Survey Telescope (LSST), the largest digital camera in astronomy. It includes an eight-meter wide-field ground-based telescope, a 3.2-gigapixel camera, and an automated data processing system.
The goal of the LSST project is simple: to survey a vast area of the sky in depth, to do so at a rate that allows every part of the visible sky to be imaged every few nights, and to continue in this mode for 10 years to produce astronomical catalogs thousands of times larger than any ever compiled before.
The LSST is currently under construction and is expected to begin operating at full capacity in October 2022: developers predict that by the end of the process, the telescope will catalog galaxies that will outnumber the number of people on Earth.
The vast public archive of data it will produce is expected to significantly advance our knowledge of dark energy and dark matter, which make up 95 percent of the universe, as well as the formation of galaxies and potentially dangerous asteroids.
LSST – the vacuum connection
Vacuum is necessary to evacuate the cryostat section of the LSST chamber, the “heart” of the chamber where the focal plane is located. This allows the LSST team to protect the core of the chamber by removing as many normal atmospheric gases as possible while controlling the pressure under very harsh environmental and operating conditions.
Inside the LSST are Agilent’s scroll pumps, ion pumps, and turbo pumps, all of which help the LSST image and catalog new galaxies. The project team chose Agilent’s ion pumps because they have no moving parts. This means there are no vibration signatures during pump operation, preventing vibrations from interfering with the LSST chamber, which would affect the quality of the data collected.
The God particle
The Higgs boson, often called the “God particle”, is an elementary particle in the Standard Model of particle physics. This model states that the fundamental forces of nature arise from properties of our universe called gauge invariance and symmetries. These forces are transmitted by particles called gauge bosons.
The Higgs boson is produced by the quantum excitation of the Higgs field, one of the fields of particle physics theory. It is thus named after physicist Peter Higgs, who in 1964, together with five other scientists, proposed the Higgs mechanism to explain why some particles have mass.
Scientists finally confirmed its existence in 2012 thanks to the ATLAS and CMS experiments at the Large Hadron Collider (LHC) at CERN* in Switzerland, which earned Higgs and Englert the 2013 Nobel Prize in Physics.
Conclusion
As science continues to advance, vacuum technology will play a vital role in the development of these extraordinary instruments and systems that capture time and space in ways beyond our imagination. The science of vacuum, which began in the 17th century, will undoubtedly be the cornerstone of many future discoveries and advances.
