Future Circular Collider

 Today was our last day of learning at CERN!

We learned about the next generation of collider from Michael Benedikt.  First, he talked about the location; that it is being proposed by CERN, a roughly 90 km ring set to fit under Lake Geneva and under the local mountains before the pre-Alps.  Once built, it will begin by being a electron-electron collider that will raise the energy of incoming electrons using a LINAC (linear accelerator) booster to get the particles up to speed.  This large collider, called the FCC (Future Circular Collider) will not accelerate the particles but maintain the energy lost as the particles turn corners and radiate synchrotron radiation.  This happens because the particles have such and incredible amount of energy that when their momentum is changed by the magnets, they emit photons and lose energy in that way.  So the four RF cavities spaced around the accelerator will be used to keep the energy at the high levels instead of continuing to add energy to the particle beam.  So whereas the previous colliders have also been accelerators, LHC, LEP, SPS, etc, this one's job is singular: collide particles.

The collider will ramp up in energy as it goes from an e-e collider to a p-p collider and will need time to make that transition just as the LEP became the LHC.  The energies created at this collider will be enough to create Higgs bosons at volume to make lot of measurements and really fine tune what we know about it and its behavior with itself and with other particles.  One colleague suggested that perhaps we will learn about the relationship between the Higgs and the proposed graviton particle which only exists at the Planck length if it exists at all.  What does that mean?  It means that the energy necessary to see it would be well above what we can generate even in the highest of energies that the FCC will reach.  

In the discussion, Michael told us about the engineering that goes into this decision, the environmental assessments, the diplomacy needed between member nations and constituents in the villages that the ring will pass under.  In their discussions, they are looking for ways to use the molasse that will be drilled from the track that is 200 meters below ground.  The material is sterile, but could be used to fill old quarries or mixed with fertilizer to make park land.  Also, the waste heat could be reappropriated to support local communities and help cheese makers in the area. The dig will take about 8 years and another year to finish the caverns for the four experiments.  All this will likely begin (assuming funding is passed and all local stakeholders agree) when the HL-LHC (High Luminosity LHC) is deactivated around 2041.  This is an incredible feat and could set up the particle physics world until 2100!!

We completed our learned with a Question and Answer Period with Dr Sascha Schmeling who is knowledgeable at every level of CERN from a user perspective to an administrator.  He has seen a thing or two, so he knows a thing or every.  He fired off answers to questions ranging for the engineering of the new FCC to detection of gravitons to AI and everything in between.  It was a wonderful Q&A session and I was so glad to be there.  What an experience it has been.  If you want to watch the final share outs, you can watch us here: at this link.

Bonsoir, tout le monde!

Antimatter and Some Field Trips

 Good morning, everyone!

This morning started with another lecture, but this time it was about how AI is used at CERN.  The main takeaways here were the massive amounts of data needed to process the amount of data generated by the LHC, roughly 40TB/s.  The data first travels to a hardware trigger that looks quickly for interesting physics.

This image is of the Trigger system of the CMS for example.

This trigger drops the data from 40 TB to 100GB/s, then this data is scoured by a machine that has been trained to look for interesting material developed by the coders.  The next Trigger drops the data transfer to 1 GB/s.  This data is sent into the world wide computer grid to be processed.  

We currently are throwing away tons of data but the questions really is, "are we throwing out anything worth keeping?" Maurizio Pierini took time to explain how machine learning could highlight some more interesting runs that would have been thrown out if the decision were left up to the first trigger.  

Later, we learned about how CERN is protected from radiation from the head of radiation protection for CERN, Claudia Ahdida.  She talked first about radiation and defined the ideas of effective dose that measures the effect of ionizing radiation on the health of someone.  It is measured in Sieverts, J/kg.  It takes into account absorbed dose and dose equivalent which is adjusted by radiation type, alpha, beta or gamma.  Lastly, to get effective dose, you must take into account the organ or tissue that is being affected.  

Protection comes in three possible methods, Justification, Limitation and Optimization.  First, anyone put into a radiation zone, must have a reason to be there; there must be a net positive reason to send someone there.  Then, workers must be limited in the time that the spend near the sources.  Finally, personal and collective doses should be made As Low As Reasonably Achievable (ALARA).  This could include training in mock situations, making fast connections or unfastening, using robots, keeping distance with extendable tools, and even using shielding.

Louis came back to spend some time talking to us about the Taming of Small Things where he talked to us about the historical growth of particle physics starting from the 1800's and the development of the processes to find the electron by JJ Thomson and the prediction of the positron by Paul Dirac.  The growth of the science led to the development of the atomic bomb and the Manhattan Engineering District  which employed nearly 130,000 people and cost $2.2 billion from 1939 to 1945, and although they tried their hardest for secrecy, the Soviet spies had stolen enough to build their own technology in a very short time.  We then discussed how by finding new science we should be focused on peaceful use and avoiding the use of findings for war.  In the case of CERN part of their philosophy  is to avoid developing research that could be used for weapons.

In the afternoon we took a field trip to the Antimatter factory were antiparticles like positrons and antiprotons are decelerated and in some cases held in stasis.  The first thing that happens to make the antimatter is the Proton Synchrotron (PS) sends protons to the factory which collide with a target that emits antiprotons.  The antiprotons enter to the AD or Antimatter Deccelerator.  Then the protons enter ELENA which slows the beam down using the same physics that accelerators use.  Lastly, the antiparticles are sent to AEGIS (Antimatter Experiement: Gravity, Interferometry, Spectroscopy), GBAR (Gravitational Behaviour of Antihydrogen at Rest), ALPHA (Antihydrogen Laser Physics Apparatus), BASE (Baryon Antibaryon Symmetry Experiment), or ASACUSA (Atomic Spectroscopy And Collisions Using Slow Antiprotons).  

With RF energy pushing back as the antiparticles pass by the RF cavity, the AD, begins to slow in the loop.  As they slow down, though, they must be cooled using an electron bath.  The electron bath enters the beam and bounces around the antiprotons to have them shake and vibrate less, which makes them have less likelihood to bounce out of the beamline.  The electrons each bounce off some antiprotons taking the energy away from the antiprotons as they speed up.  This same process occurs again in ELENA to make the antiparticles even slower.

GBAR uses first year physics to test for the relationship between antimatter and gravity by testing how antiparticles behave in a horizontal launch. 

The last experiment we visited was AEGIS that attempts to trap and experiment with antihydrogen and then record observations made using gravitational and spectroscopy to see if it behaves as hydrogen does. 

After the trip to the AF, we went to see the LEIR, Low Energy Ion Ring.  Because the LHC is currently using protons, experimenters do not need to accelerate large ions like lead, so we were able to go in and see the accelerator up close. 

We also got to see the remains of LINAC 2, the linear accelerator that pushed the protons that created the data to help find the Higgs boson. 

We also got to listen to the current heartbeat of the LHC, LINAC 4 that accelerates protons to enter the PS then the BOOSTER and  then SPS and finally LHC (for now).  Humming with a period of 1.2s, the accelerator pushes particles into the accelerator chain.

Finished with a game of cribbage with my colleague from Canada! 

I lost, but that was a fun game!

 

Alice and LHCb

 Hello, all you readers out there!

Today we are hopefully breaking the heat wave and we can start to breathe tomorrow.  My colleagues from Lebanon, Egypt, Peru and Canada and I went into the city for a sunrise concert of Cello and Harp.  It was really a beautiful start to the day.  

It was a really hot one, but we started in the basement of building 40 where we learned about the LHCb, a detector designed to observe physics focused on the bottom quark, or beauty quark in their eyes.  The LHCb is a detector that looks for a decay of the Bs or B0 in hopes of finding more information about why there is more matter than antimatter.  

Paul Dirac first postulated that there would be antielectrons because he was able to solve his electron equations with negative numbers, hinting at an antielectron.  His hypothesis led to his Nobel Prize.  The problem is that we should have just as much matter as antimatter and we don't.  If we did, there would be no matter left, it would just keep annhilating.  We see, though, that there is a net matter and there is slightly less antimatter.  This is called CP violation.  Now it seems right now that all findings are pointing to the fact that the standard model confirms CP violation, but this is a problem for Cosmologists because they want more violations than the standard model predicts.  This deficit is one of the things that the LHCb is looking for.  

The experiment, which we visited later in the day, is based on a linear design.  They want all the information that they can get, but only in the forward direction.  They are ok with losing the backward direction.  They only had 26 meters, so it was either build 2 13-meter detectors or 1 26 meter detector.  They chose the one that would give them the most to look at.  One of the interesting things that this detector looks at is Cherenkov radiation which is the radiation given off when a particle is traveling faster than the speed that light can travel in that medium.  This happens in nuclear reactors and in relativistic situations like this detector presents. 

We also learned about the ALICE detector that allows for us to measure and investigate the gluon plasma created when a heavy ion collides with another heavy ion traveling near the speed of light. ALICE stands for A Large Ion Collision Experiment and that is exactly what it does.  It strips atoms of the electrons and slams large nuclei into each other to create the material that existed at the Big Bang, these collisions are called "Little Bangs." 

In the ALICE detector, gluons and quarks are not seen alone, but they instead investigate the relative numbers of the secondary larger particles, called Frozen out Hadrons.  The relative numbers can be hypothesized using the standard model and then the experiment can confirm what the gluon plasma must have looked like given the energy of the collision and how many particles were involved. 

 

The ALICE control room was fun.  Since it was ALICE, the folks in the room wore bunny ears symbolizing the White Hare.  We saw the parts of the detector and were able to investigate the cavern above the ALICE detector itself.

We finished the night with some really incredible food and a gift exchange and some multicultural extravaganzaness.  It was really a great time.  So much laughing and smiling and good stories.  I have some fun things to share when I get home. 

Computing and Data Analysis at CERN

 Bonjour Tout le Monde!

It is getting hazy, hot, and humid in Geneva.  You can't see Mont Blanc at all.  She's been gone for three days, but today she is non-existent.  It will hit 100 tomorrow and we are officially at the peak of the heat wave.  

The temperature gets hotter but the physics gets cooler!  Today we walked from Switzerland to France in the CERN complex and went to learn about computing at CERN from Marcus Joos.

Marcus has been with CERN since before the Higgs was found and has been writing program since he was in high school.  Now Marcus' big takeaway for us was to realize that when he looks at CV's from students all over the world, he isn't looking for all A's because he can't compare one school system to another or one school district to another, he looks for passion.  That was the big take away.  Why do you use computing?  How do you use it when there isn't a teacher making you?  Some interesting things to think about are that CERN, despite needing Petabytes to calculate its data from detectors uses the least amount out of Facebook, CERN and Amazon.  CERN uses 450,000 computer cores, independently running processing units.  Each experiment runs 50,000 each (ATLAS, CMS, LHCb and ALICE).  There are about 1,000,000 other units used world wide in the computing grid. 

Some things we talked about were the operating system, Linux, the primary coding language, C/C++, and the need to remain free from the thumb of Microsoft, et al. who try to raise prices and really hold you under threat.  To the question of "should I learn to code in school?," he responds, "Do you want to be the driver in the car or the passenger in the bus?"  How much freedom you have depends on the amount of skill you possess.

We were then able to visit the DATA CENTER on campus which is basically in charge of the day to day things as well as the web connection.  Most of the number crunching from experiments from after trigger 2 happens on the other campus in France.  Trigger 1 happens on premises of each experiment and drops the 100,000,000 collisions/second to 100 high interest collisions per second.  Then the secondary trigger drops those down to about 10 collisions/ second that are sent off to the world to be processed.  Another interesting point to note, this room was once the ONLY direct connection for the internet to reach from Europe to Chicago, IL where Fermilab is located.  It also manages the connections for the EU and the UN.

How long would it have take in each of these years to process the information obtained by 1 year of operation at CERN?

back left is in charge of the EU and UN and other stuff

Free look at what is happening.  Everything at CERN is open source

We took some time as well to inspect mystery boxes and think about how to implement them in our classes.  I will be making some interesting boxes for day 1!  Get ready, students.  

My partner was my colleague from Italy

Lastly, we heard a lecture from Dr.  Flavia de Almeida Dias, who talked to us about data analysis.  She worked on CMS before the Higgs and now works for ATLAS.  She is interested in finding new physics in the data from the LHC experiments, so she has to investigate the data that makes in through the triggers to look for interesting data that pops up above the background data at a level that would be unthinkable otherwise.  For example, if the peak at 125 GeV in the 2012 paper was not the Higgs and was instead random background, that would be a 0.000035% chance.  Statistically improbable, and having now found several Higgs candidates, we can say pretty positively that it is likely the real deal. 

We ended the night with some UNO....I did not win. Pictured colleagues from (front: Portugal, rt to left: Italy, Italy again, Canada, Hungary, Serbia, Estonia, me, US, Lebanon, Australia)

The Weekend

 To catch you all up quickly, this weekend was an unbelievably busy one.  I started off Saturday with a sunrise concert featuring an Irish folk band named The Woodgies and they were phenomenal. 

I also got a chance to go swimming to start the day which was great.

After, we walked around a bit and headed back to CERN before starting the all day scavenger hunt.  We walked around the entirety of Geneva seeing Museums, 

rivers,

sites, 

stores, 

and so much more.  

At the end, we had a traditional Cheese Fondue which was absolutely amazing.

Sunday brought me on a trip to Chamonix, France where I took a cable car up to the top of Mont Blanc just 1000 m below the very peak, but it didn't look like 1000m.  I was at 3842 and that was plenty high! 

We took a train to a glacier

 and then walked around Chamonix for a bit.