Large Hadron Collider: World's Largest Particle Accelerator

How Large Hadron Collider Works

Question:

Discuss about the Engineering Marvel for Large Hadron Collider.

Large Hadron Collider as the name suggests is the world's largest and the most powerful particle accelerator. Initiated on 10 September 2008, the large hadron collider is still in regularly developing stage and is the latest addition to the CERN's (European Organization for Nuclear Research) accelerator campus which is located on France- Switzerland border near Geneva. The LHC is made up of a 27 kilometer ring which comprises of superconducting magnets along with powerful particle accelerators which helps to boost the energy of particles along the way.

The working of LHC is complex yet the methodology is simple. In the LHC, two energy particle beams are made to travel at the speed of light and then they are made to collide. These energy particles travel in opposite directions in two separate pipes which are ultrahigh vacuumed to avoid any kind of resistance to the particles. These particles are guided by a strong magnetic field which is ensured by superconducting electromagnets. These particles travel in the accelerator ring. The electromagnets are built from electric cables which are made from special coils. For these magnets to work efficiently and conduct electricity without any loss of energy, these agents are chilled to the temperature of -271.3 ^oC which is even colder than outer space. The chilling of these magnets is done by using liquid helium, which not only cools magnets but also other parts of the mega machine. In LHC thousands of magnets of varied sizes are used to direct the particles. The large hadron collider comprises of 1232 dipole magnets of 15 meters which are used to bend the beam and 392 quadrupole magnets each of 5-7 meters of length which are used to focus the beams. Just before the collision another set of magnets is used to squeeze the particles so that the chances of collision may increase. Colliding a particle in the LHC is like firing two needles in opposite directions from 10 kilometers apart and that too with such precision that they both meet halfway. All the technicalities, controls, services of the LHC are housed under one roof i.e. the control room at CERN. Controlled from here the beams are made to collide at four locations inside the accelerator ring. These four particle detectors are ATLAS, CMS, ALICE and LHCb.

Inside the accelerator around 3000 bunches of particles are accelerated which contains as many as 100 billion particles. These particles are so insignificant in the terms of size that colliding them is a very cumbersome task and even the chances are low. At the time when these particles cross each other, only 40 collisions take place between 200 billion particles. These bunches crosses each other 30 million times in a second! The LHC thus collides around 1 billion particles per second (CERN, 2017; CERN, 2017). 

The LHC has many benefits which includes Technological development, Workforce development and the Core science. The benefits derived from the research at LHC are discussed below in details: (CERN, 2017)

Magnets and Particle Accelerators

Apart from space exploration and solving the mysteries of outer space, the research conducted at LHC can give the answer to many unsolved theories and questions which haven't been answered before. Followings are the examples of how development of this technology has benefitted the technological development:

• Cancer therapy- The accelerator physics has been able to develop the concept of high energy physics in which the particles can now be focused to a small area and they will interact only at the desired location instead of the entire path which helps to determine the area of cancer increase the effectiveness of the treatment. The advanced treatment of cancer lies in acceleration physics so the technology and the method used in LHC has given an answer to treat the disease in a better way.
• Manufacturing processes- The technology of accelerator physics has also helped in cleaning the process of manufacturing of materials. For ex. The process of tire manufacturing requires vulcanization of rubber which was earlier done through using chemicals but now with the help of accelerator physics the process of vulcanization has become cleaner with minimum or no use of chemicals.
• Medical and industrial imaging- The cameras used in the process of body and material imaging is the same used in the particle accelerator but the advancement of the technology in used in LHC has helped to make the process easier and better.
• Pattern Recognition- The first pattern recognition algorithms were developed to recognize the tracks of particle in the form of images of interactions. The process has developed its own importance in the years but the basics of the methods have been derived from particle physics.
• Grid/cloud computing- The researchers working at LHC and those who worked at Tevatron (the predecessor the LHC) have contributed significantly to cloud/grid computing. The experiments conducted at LHC require huge amour of space to be stores as the information is plenty. The information is produced at LHC is around tens of petabytes annually. This information is stored, processed and distributed by the means of grid computing.
• The world wide web- Before the development of the web page, the internet was only composed of email, ftp servers and usenets. The web page was developed and was first introduced by CERN so that the researchers were able to share the information about high energy physics. 

The challenges which were faced by the scientists at the LHC campus were not ordinary and required an entirely unique set of skills and techniques of problem solving by the workers. Cultivated by core science, this technical mindset and expertise can be a valuable skillset to the field of particle acceleration and many other research fields. Additionally it was not possible to develop the LHC if it wasn't for the workers who left their industry job and contributed in the development of the technology (BBC News, 2015).

The benefits of technology and workforce are of short term and are achieved by the pursuit of problem finding will to the questions remained unanswered. So the funding of such projects depends on the perceived scientific benefits. The concept and the theoretical assumptions of LHC will not only help us to get to know universe but it will also increase our understanding about nuclear physics and quantum technology by accelerating the particles at speed which has never been done yet. Following are the aims of Large Hadron Collider:

• To search for the Higgs Boson particle this is predicted by the Standard model. This particle helps the other particle to acquire mass.
• To search the answer to the inconsistency of the particle based on the standard model.
• To search for the sources of dark matter.
• To search for the mystery of matter-antimatter asymmetry in the universe.
• To measure the size and structure of proton.
• To be able to understand the nature of cosmic rays and how they interact with our atmosphere.
• To confirm the existence of quark-gluon plasma and to know about its properties.

The research conducted at CERN will also help to know about the concept of anti-gravity drives i.e. the ability to fold space which is just a speculative assumption for now. The practical benefits of LHC are still unknown so we will refer to the historical examples instead. From what is known is that the understating the theories like quantum field theory have generated many practical benefits in the past which are stated below:

• Developed about a century ago, initially the quantum mechanics was just another theory filled with puzzles and unanswered questions with no practical application. Around 50 years age a transistor was developed which helped us to understand the concept of quantum theory and quantum mechanics. The transistor comprised of the core of many computer chips. Without this transistor, the computers will still be made of vacuum tubes and would occupy large space. This led to the development of personal computer, laptops, smart phones etc.
• Studies related to atom have helped to develop the concept and working of nuclear power and nuclear bombs. Though the process of development of this technology has been long and frustrating the study has helped to generate the clean and safe source of power. The only drawback of this research is that the negative effects and uses of technology are more than positive effects. If fallen into wrong hands, this technology can have devastating effects.
• Another major research conducted around 150 years ago was the study of fundamental electromagnetism which shares it fundamental concepts with particle physics. The benefits yielded from this research is used by electrical engineers which has allowed them to create radios, batteries, the mathematically modeled effects of interference in circuits and many other.

The specialty of LHC is that it squeezes the energy of collision in a space million times smaller. The particles when collide produces the energy around 14V, but in LHC the researchers have been able to reach the level of 1150V which is higher than ever recorded in history. We can compare this achievement by taking an example from daily routine; the energy produced while we clap our hands is much more than what was achieved at CERN but it is evenly distributed around our palm. The achievement of LHC is that it has been able to produce the same level of energy but at a million times smaller space (CERN, 2017). 

A structure like LHC is not possible to build without facing any challenges. The development of LHC faced engineering challenges across every virtual engineering discipline. The major challenge was placing and maintaining magnets and cryogenics which are discussed below (Collier, 2015; Schmidt & Vergara, 2002; Alonso, 2015):

1. Magnets- In an electromagnet which is used in particle accelerator, the current flowing through the coils generates field. In an ordinary electromagnet this field can be limited by using iron yoke through which the coil passes whose closeness to the beam pipe determines the quality and strength of the field. This type of magnet is limited by the saturation of the iron yoke to a central field produced around. In a superconducting magnet, the field is generated directly by suitable distribution of the current arranged properly around the beam pipe. Placing magnets accurately was the most difficult challenge faced by the engineers. These magnets are used to direct the beam around the accelerator. The cumbersome task was placing these magnets precisely so that the particles could collide. If any one of these magnets was placed incorrectly the consequences could be life threatening also the collision won’t take place. This could also damage the whole machine. Another problem with the magnetic placement was that all these magnets were electromagnets and they tend to lose their strength and potency from time-to-time. Many incidents have been reported where magnets have failed catastrophically which led to failure of tests. The constant failures were another challenge faced by the machine as it wasted a lot of energy. The working of LHC required the energy in huge units and this energy was needed regularly. Energy requirements of the Large Hadron Collider are incredibly high because the machine can’t be stopped. Searching for a stable source of energy to electrify magnets was another challenge faced by the engineers.
2. Cryogenics- This was the biggest challenge faced by the engineers working at CERN on the LHC. The aim was to increase the potency of the electromagnets which regularly gets used up during the process and lose its strength. Another issue was to cool down the 27 km long setup which gets immensely used up because of working at high energy levels. The answers to the questions were many but the most promising was liquid helium. The problem now the scientists faced was the cost of the machine was already touching roof and this was another expensive addition to the system. Acquiring liquid helium was not tough but it was very expensive and it was required in huge amount. Another complication was the maintenance required by this substance. Liquid helium requires high maintenance to maintain its temperature so it was stored in special containers which would keep the substance safe from the affects of the particle beam. The electromagnets were immersed in the substance so that its strength was maintained which helped it to reach the chilling temperature of 271.3 ^o This issue was though solved by the engineers but maintenance and procurement of liquid helium still remains a costly task and researchers are regularly working on procuring a better and inexpensive substance which will be the essence of the cryogenic system of LHC.
3. Societal Challenges- The social challenges faced by the LHC were less and were answered by the researchers so that people may feel safe. Yet the major issue LHC faced was the high energy requirements. The machine used to work for 10 days just for a single operation because the rates of collisions were less. Such huge machines are also hard to start and even this process can take many days. The high energy requirements for such operations were becoming an issue as it was constantly using up valuable resources and that too in huge amounts. Apart from this many people also feared that the working of machine would re-create a parallel universe which may give rise to the sources of dark energy such as black hole. A black hole is so powerful that it can even suck planets and stars in it. But this concern of people was answered by scientists because even if any black hole will form it will be of very small size and would disappear instantly without causing any damage(The Telegraph, 2010). 

Conclusion

After 25 years of hard work the LHC was commissioned at intermediate energy and performed well during the early stage of its operations. Even in the early stage, the machine was able to provide data which helped the scientists to discover and know the properties of the God Particle i.ee Higgs Boson. During the period of operations the machine also went under a two year shutdown period from 2013-2015. The machine is now in operational mode and the next shutdown will take place halfway in 2018. This period of operations has been very exciting and is expected to provide more specific data and answers to many questions. So it can be concluded that throughout its operational period the Large Hadron Collider has confronted many technical, engineering, operational and social challenges and has been successful in helping us to get to know the universe. This scientific invention can thus be stated as an engineering marvel which is expected to give many other insights in the future. 

References

Alonso, I. B. (2015). HL-LHC challenges and impact in a nutshell. Hi Lumi HL-LHC Project.

BBC News. (2015, March 28). What is the point of large Hadron Collider? Retrieved 2017, from Bbc.com: https://www.bbc.com/news/science-environment-32087787

CERN. (2017). CERN-Brochure. Retrieved from Cds.cern.ch: https://cds.cern.ch/record/2255762/files/CERN-Brochure-2017-002-Eng.pdf

CERN. (2017). The Large Hadron Collider. Retrieved from Home.cern: https://home.cern/topics/large-hadron-collider

Collier, P. (2015). The technical challenges of the Large Hadron Collider. Philosophical Transaction A Royal Society.

Schmidt, R., & Vergara, A. (2002). Machine Protection and Interlock System for the LHC. Grenoble.

The Telegraph. (2010, March 30). Large Hadron Collider hits problems as scientists bid to start high energy collissions. Retrieved 2017, from Telegraph.co.uk: https://www.telegraph.co.uk/news/science/large-hadron-collider/7537355/Large-Hadron-Collider-hits-problems-as-scientists-bid-to-start-high-energy-collisions.html