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Archive for February, 2011

My Crazy Semester: Thesis Writing

Monday, February 28th, 2011

Oops, I seem to have done things in the wrong order. The good news is that I have a job lined up for when I graduate. The… challenging… news is that I still have a few things to finish here in Berkeley: little things, like finalizing my analysis and writing my thesis! This has made for a rather busy semester, to say the least.

From the perspective of readers here, though, I’m not going anywhere fast. I will be switching universities, and (gasp!) switching experiments, but in neither case am I going far enough that I fall outside the subject of this blog. I didn’t mean “far enough” too literally, but the distances are about 2500 miles and 5.3 miles respectively.

This gives me lots to write about, so let me start with my thesis. It’s not that much fun. It has two parts: background stuff I have to look up, and describing my analysis in more detail. But it is, I have to admit, probably all wortwhile. The former part is all stuff that’s relevant to my work and I ought to be able to describe off the top of my head — and in fact, I usually can, but not with all the numbers and equations and details just right. The latter part is a good chance to really document what I did in my analysis, which is information that might not be public elsewhere. Maybe someone, someday, will want to look up what I did. Maybe I’ll look it up myself out of nostalgia. Once I get my thesis written at last, though, one thing I’m sure of: I won’t look at it again for a while. I’m already ready to move on!

While I’m working on that, here are some goodies from my thesis. The output of a helpful script I wrote:

Seth-Zenzs-MacBook-Pro:~ sethzenz$ python scripts/thesistimeleft.py

You have 75 days left to file your thesis!!!

It recalculates every day. I could make it send me automatic emails, if I really want to make myself nervous.

And here’s a bit of my (first draft) introduction, which tries to explain how my work fits into the overall context of the LHC program:

The Large Hadron Collider (LHC) was built to produce new particles and rare interactions at a high rate, but its first and foremost byproduct is sprays of low-energy hadrons. At its full design capacity, the LHC will cross proton bunches 31.6 million times per second at each interaction point, with an average of about 20 proton-proton collisions per crossing. Most of these collisions will be “soft” interactions, with relatively little energy exchanged and the outgoing hadrons having relatively little momentum perpendicular to the beam axis. These interactions are described in principle by Quantum Chromodynamics (QCD), the quantum field theory of the strong interactions. In practice, however, they are the most difficult to understand, because the theory becomes non-perturbative at low energies. Predictions can only be made via approximations and phenomenological models. This difficulty with low-energy strong interactions appears even in interactions that are initially well-described by perturbation theory. Outgoing high-energy quarks and gluons quickly “clothe” their strong color charge by evolving into jets of lower-energy hadrons, a process that again requires approximation and modelling.

The LHC’s general-purpose experiments, ATLAS and CMS, are equipped with multi-stage trigger systems that select against these common processes, for example by identifying leptons and missing energy produced in electroweak interactions. However, low-energy QCD still has a significant impact on the physics program in several areas. With so many collisions in each crossing, the most interesting collisions will have many low-energy collisions whose signals in the detector overlap with the objects of interest. In order for their effects to be subtracted, these features of these pileup collisions must be known quantitatively. The evolution of high-energy hadronic jets must also be well-understood. This is partially to account for their contribution as pileup events, but their energy must also be calibrated so they can be studied in their own right. Although even very high-energy jets are relatively common at the LHC, they can also serve as signatures of the decay of new particles.

The quantitative investigation of low-energy QCD is thus a foundational element of the LHC program, which will inform the studies and discoveries of the coming years. Initial low-energy QCD measurements have divided the problem between low-energy events and the study of higher-energy jet properties. In the former case, inclusive charged particle distributions are produced from events identified using a “minimum bias” trigger. In the latter case, higher-energy jets are triggered and studied using the calorimeter system built for the purpose.

This work focuses on the additional information to be gained in the case that the two issues are not-so easily factorized, by studying the emergence of low-energy jets from soft interactions. Particles are identified using the methods of the lowest-energy measurements, but grouped together into jets according to the algorithms used to study jets at higher energies. Low-momentum jets and their properties are measured using the ATLAS Inner Detector, the component of the ATLAS experiment that tracks charged particles, in events identified using the ATLAS Minimum Bias Trigger Scintilators.

That’s very unlikely to be final, but in any case that gives you a picture of the sort of thing I’m working on.

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Breakfast in India, with Cricket

Sunday, February 27th, 2011

–By Nigel S. Lockyer, Director

[Ed. Note: This is the first of a three-part series penned by Nigel on his trip to India in early March 2011.]

I don’t start everyday reading the Hindustantimes sitting in a restaurant in Delhi having breakfast. It is not a bad paper. I have read the India Times for a few years online and I am going to switch now. Here, all the talk is the about the Cricket World Cup. Today, 2:00PM, England versus India. I hadn’t been here for more than two hours before the name Sachin Tendulkar came up. He is the top cricket player in the world, or so they say here. When Sachin is combined with his teammate Virender Sehwag, the Indians said they felt sorry for the English.   History has moved on in India I guess. You can feel the swagger. However the expectations cannot be met in all likelihood. Mahendra Singh Dhoni,  the captain, is clearly in a pressure cooker situation. The local paper says ” Mahendra Singh Dhoni,….holds the second-most high-pressure job after the Prime Minister in the country…”…I think that pretty much sums it up.

Oh, yes, I must have missed the tickets mess, that was a national disaster by the sounds of it. Police lathi-charged fans waiting to get tickets. Lathi is a stick introduced to India by the English for crowd control in the old days. It is highly ironic they are now being used to control crowds awaiting the England-India cricket match fans. Given the crazy world of Iraq, Afghanistan, Libya and everything else painful going on, I fully appreciate and am thankful to countries where priorities are recognized and appropriately set…think  Canada and Stanley Cup playoffs…the world news stops for the important stuff.

I was looking in the newspaper for anything to do with science. After all, India is big on technology and has a rich history in physics. Found one….electromagnetic radiations (newspaper provided the “s”, yes radiations) from mobile towers, particularly near your home, can be hazardous. The article was factual and said scientific evidence was not there yet so Delhi was being cautious and ruled that cell phone towers are not allowed near schools, hospitals, or homes. That is more progressive than Vancouver or Toronto. Oh, and the 700 million cell phone users in India is an amazing number along with 5.4 lakh towers (units in 100,000). That is to be compared with about 1000 cell phone towers in Toronto….TO residents are fighting them from being in their back yards. India plus one!

I am now going to pray like mad to Pavanputra Hanuman that I can get my talk finished for tomorrow in Kolkata.

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Fifteen inches of snow and blowing winds make many roads impassable in and around Fermilab. Courtesy Darren Crawford

Media and town officials said it was too dangerous to be outside; stay home, they said; enjoy a rare adult snow day. Schools closed, businesses closed, postal delivery ceased.

But operation of the Tevatron did not.

Amidst the worst blizzard in decades Feb. 1, with nearly 15 inches of snow and more than 50 mph winds producing even higher drifts, the crews that keep Fermilab’s accelerators, detectors and cryogenics systems running showed up for work.  They brought extra food and clothes, snow shoes and a determined attitude that bad weather would not best them.

Think of the accelerator operators as the Marine Corp. of science: they do the job when no one else wants to; they are the first line of defense.  The accelerator complex never ever sleeps, even with the rest of the U.S. under a blanket of snow. Shutting it down would require lengthy restart periods.

“You can’t just turn it off,” said Dan Johnson, head of the Accelerator Division’s Operations Department.  “Even when the accelerators aren’t accelerating beam all the support systems have to run. The Tevatron has to stay cold, we still need vacuum, we still need water. If you’re not careful, the accelerator tunnel could flood.

 “We just knew they were going to be here if they had to walk in with snow shoes on,” Johnson, said of the operators.  “It presented a challenge and they love a challenge so they just handled it.”

And boy did they have challenges.

Some started work early to avoid getting trapped in unplowed roads and missing their midnight shifts; others stayed late to cover for employees who lived far away and couldn’t make it in.  Some such as Aron Soha at CDF and Darren Crawford  in the Main Control Room put in 15-to 18-hour shift, catching brief respites of shut eye in out of the way rooms.

At 4 a.m.at the height of the blizzard with blowing snow nearly erasing the roadways, the Main Control Room got a call from the Meson Test Beam area from an experimenter who had struggled in from the village and said he was ready to take beam.

“That was a jaw dropper,” said Darren Crawford, operations crew chief that night.

What was not surprising was the lack of complaining.  People stayed positive, watching the weather and joking about how they beat it. Managers called in from home to check on employees throughout the lab and the Main Control Room crew made wellness check calls to CDF and DZero. The detector crews monitored the Main Control Room logbook as two operators braved the cold and near white-out conditions to attempt repairs.

A safety detector shut off on top of the MiniBooNE berm near the MiniBooNE service building, immediately killing the beam in the Main Injector.  Crews feared blowing snow or snow lightening had shorted it out.

Chris Olsen is forced to use snow shoes to check on a safety detector during the blizzard. Courtesy Darren Crawford

Checking it meant someone had to trudge halfway across the lab, in the dark, blowing snow and below-zero temperatures. A 5-minute drive turned in to 20 minutes. With only the main road plowed, operator Chris Olsen had to strap on snow shoes and tramp about 30 yards through uneven snow-filled terrain to find the detector, open it, unwrap the electronics and check it.

 After more than 15 freezing minutes, he discovered the detector hardware was fine; the problem was with the electronics card in the nice, warm service building. It turned out snow lightening had shorted out the system.  

FESS HV engineers  couldn’t get to the lab through the snow until morning. Then operators and FESS Roads and Grounds personnel helped

Two members of Fermilab’s Roads and Grounds crew clear sidewalks on Wednesday, Feb. 2, after a blizzard.

shovel a path for them to electrical boxes and hand-hauled equipment through parking lots buried in snow. First power to the Village was restored; then the Main Injector and then AD interlock technicans were able to bring the MiniBooNE safety detector back online.

Even though the Main Injector had been shut down, the last shot of protons and antiprotons before the outage continued to circle the Tevatron through the storm and beyond, providing data for CDF and DZero to analyze for 49 hours.

“We called it the little store that could,” Crawford said.

— Tona Kunz

See a Fermilab Today story about how other employees at the lab kept science doable during the blizzard.

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News from Double Chooz

Friday, February 25th, 2011

There was a nice article about the Double Chooz experiment in Symmetry Breaking recently.  It was also featured in today’s Fermilab Today news letter.  Since I don’t think I have posted an explanation of the experiment I thought I would just share this link to the article.

Last week the Double Chooz collaboration met in Heidelberg, Germany at the Max-Plank-Institute for Nuclear Physics.  This was a very exciting meeting because the first detector has been up and running for a few months now, and people have had a chance to look at the data.

This was my first meeting in Europe, and my first time ever in Germany.  The flight from California was arduousness, 11 hours, but we did fly non-stop which at least allowed for the possibility of sleep.  I dozed in and out a little, and then had to give a talk to the collaboration exactly 24 hours after I woke up that day!  It was a long day, but to my surprise I had plenty of energy to give a good talk.  The coffee helped too!

Unfortunately, our trip did not allow for any sightseeing.  There is a really neat castle in Heidelberg that we saw while walking to dinner, I would have liked to take a look inside.  We did have a nice dinner at an old German beer house.  Long wooden tables, family style meal, and large beer steins, what more could you ask for?

Although our detector is pumping out it’s first data, installation is not entirely complete.  UC Davis is responsible for the fabrication and installation of a glove box (yep, a big box that you stick your hands into) which will allow us to deploy radioactive sources into our detector for calibration.  Basically, we need to introduce a known signal and compare it with what our detector sees.  This allows us to better understand how well we can reconstruct the position and energy of neutrino interactions inside our detector.  Late next month I will go to Chooz to install the glove box and stay for a few months to deploy the sources.  Perhaps my next post will be from France.  Au Revoir.

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Block Ed

Thursday, February 24th, 2011

–by T. “Isaac” Meyer, Head of Strategic Planning and Communications

Well, I’m struggling. I agreed to give a talk in India at the Frontiers of Science Symposium in Kolkata on March 2-3, 2011, about “science and industry collaboration.” You’d think that with our recent submission to the government on exactly this topic and my experience and expertise in this area, it’d be an easy talk to write.

But, I’m encountering writers’ block. I’m not writing, I’m using Microsoft PowerPoint, so maybe it’s sliders’ block or bulleted-list-persons’ block. What do you call someone who uses PPT to communicate?

Based on a conversation in the lunch room, I got my thesis clear so now I just hang the fruited examples on those branches and a beautiful tree I will have.

Stay focused!

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The Future of Fermilab

Thursday, February 24th, 2011

This article ran in Fermilab Today, Feb. 23.

The era of the Tevatron is about to come to a close. The Tevatron has certainly been the showcase of our physics program for more than 25 years, but it is only one of nine accelerators and storage rings that make up our complex.

Fermilab’s plan for the future includes upgrading its lower-energy accelerators and using them for new experiments including the NOvA neutrino experiment and several other experiments that will take advantage of an upgraded Proton Source, Main Injector and Recycler. These upgrades will begin next year. The Main Injector and Recycler upgrades will be completed during the major shutdown of the complex scheduled to begin in March 2012 and last about one year.

Further in the future our laboratory will focus on Project X, which will take us into the high-intensity realm. This proposed experimental program should open windows to new physics that we may never reach by going to higher and higher energies. Pursuit of these questions has brought us to the understanding of the world that we have now, and has created the amazing world that we live in today.

Creating such an exciting future for Fermilab will take the same kind of dedication and talent that Fermilab employees have demonstrated over the past 25 years in order to make the Tevatron a success. I have no doubt that we have the talent necessary to achieve even more impressive goals in the future.

— Roger Dixon, head of the Fermilab Accelerator Division

To learn more about Fermilab’s current experiments and future plans, view the Plan for the Future website.

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The Mu2e Experiment: You Ordered What?

Wednesday, February 23rd, 2011

This first Mu2e blog is designed to serve as an introduction to the purpose of the experiment. Stay tuned to Quantum Diaries for future Mu2e posts regarding some of the more subtle aspects of this unique experiment.

The layout of the Mu2e experiment. Muons are produced from a proton beam hitting a target and captured using magnetic fields. They are then transferred down the s-shaped transfer line to the stopping target . Stopped muons will decay, and the resulting electron will be studied using the particle detectors. Credit: symmetry magazine/Sandbox Studio

When the muon — a heavy version of the electron — was discovered, Isidor Rabi famously asked, “Who ordered that?”

Well, the Mu2e experiment at Fermilab would now like to place its order for 1020, or 100 trillion, of these interesting particles. To put this staggering number in context, the Mu2e experiment needs almost as many muons as there are grains of sand on Earth.

Since the time of its discovery, scientists have questioned why the muon wouldn’t decay directly into an electron and a photon. It seems like a natural decay if the muon is just a heavy version of the electron. However, this decay has never been observed. 

Similar to the decay, it may be possible for a muon to convert directly into an electron in the presence of a nucleus (the nucleus is required to conserve momentum and energy). Experimental limits suggest that if this occurs at all, it must occur for less than one out of 10 13 , or 10 billion, muons. The Mu2e experiment needs so many muons because it plans to improve on the sensitivity of previous experiments to this so called muon-to-electron conversion by four orders of magnitude. That is, the goal of the first two-year run of the experiment is to be sensitive to this process even if only one muon out of 10 17 , or 100 billiard. converts into an electron in this way. A plan for future experimental runs may even improve this by two more orders of magnitude.

 Can’t wait for the next blog?   Then check out these sites for more information:

— Craig Group

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Budgets, DUSEL, and LBNE

Wednesday, February 23rd, 2011

I know it has been a week or two since this was breaking news, but I wanted to discuss the recent budget cuts and how they could impact my life as a young scientist.  The Presidents FY12 budget called for the termination of NSF funding of DUSEL, the proposed Deep Underground Science and Engineering Laboratory, in the Homestake mine in South Dakota, see below.  The purpose of DUSEL was to provide an underground laboratory for scientific experiments, and is most needed for particle physics experiments including neutrino oscillations, supernova neutrinos, direct dark matter searches, neutrinoless double beta decay searches, and other experiments which require a low cosmic ray background.  The decision to terminate NSF funding for DUSEL was a bit of a shock; however, just a few weeks earlier an internal NSF committee decided to not award supplemental funds to the DUSEL design team.  Perhaps a sign of things to come.  It is worth remembering that this is the administrations take on the budget situation, and congress might have a different opinion.  Either way, we are not off to a good start.

Although DUSEL has taken a big hit, the Long Baseline Neutrino Experiment (LBNE) remains a high priority for the Department of Energy independent of DUSEL.  This is comforting to hear for someone with an interest in LBNE and neutrino oscillation physics, but without DUSEL a lot of other interesting science is likely to go unstudied.  In the US at least.

Heres keeping our fingers crossed, and please see other posts for instructions to contact your congress person to show your support.

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Going in Circles

Wednesday, February 23rd, 2011

RHIC's main control room

If you were expecting this blog entry to be about the great song from the Friends of Distinction, it unfortunately won’t be the case. Instead, I’m taking you on the first trip this year of RHIC’s Yellow beam, one of two oppositely circulating particle beams that collide in the center of RHIC’s detectors. Why? Because the main goal of my first shift of Run11 was to get our particles to circulate in a closed orbit in the Yellow beamline. This will also give me the opportunity to get back to some of the technical terms I used in my previous post. So allow me to go over a little bit of accelerator physics theory for a minute.

RHIC, which stands for Relativistic Heavy Ion Collider, is the name given to the large circular collider at Brookhaven National Laboratory; in order for particles to actually reach the collider from their source, they need travel through a series of other accelerators:

  1. the LINAC for protons, the Tandem-to-Booster beamline for heavy ions
  2. the Booster synchrotron
  3. the Booster-to-AGS (BtA) line
  4. the Alternating Gradient Synchrotron (AGS)
  5. the AGS-to-RHIC (AtR) line

(more…)

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 Many media outlets have been discussing the potential impacts on Fermilab of a proposed 20 percent cut in the current fiscal year’s funding through the Department of Energy’s Office of Science. Scientific American wrote about how the cuts would prematurely shutter the Tevatron. Geneva Patch.com wrote about potential layoffs and furloughs at Fermilab and Argonne national labs and how that might affect local business that support the laboratories and their employees.

The proposed cuts come as part of an appropriations bill for the FY2011 budget, which has yet to be approved even though five months of the budget year have passed.  Government has been working on a continuing resolution, which assumed budget levels stayed flat, but that continuing resolution expires March 4. The proposed House budget would not keep funding levels flat for key science agenciess as assumed by the continuing resolution but cut them by 20 percent, requiring labs such as Fermilab to come up with a year’s worth of savings in the last six months of the budget year. That equates to a 40 percent cut in six months, as Fermilab Director Pier Oddone has stated.

GenevaPatch.com published a letter that Illinois Senator Dick Durbin sent to fellow Congressmen and Congresswomen about proposed cuts to a key funding source of national laboratories.

… cuts critical research and robs 10,000 American workers of their jobs during a very weak economy.  This is not the path to economic growth.  We need to invest in crucial research that fuels American innovation.  Fiscal responsibility demands thoughtful allocation of our resources that will lead us to a stronger economic standing.  …  I look forward to working with you to ensure that our labs continue their world-class research.

Durbin stressed in a previous press release the need to balance needed cuts with continued support of industry and R&D that will promote innovation, and thus jobs. The President’s proposed FY2012 budget supports science and keeps funding for Fermilab relatively flat from FY2010 levels.

Finally, the President’s Budget also recommends targeted investments in key research and development programs for the next fiscal year to help promote innovation on our campuses and in our labs so that the growth industries of tomorrow are founded here today.

—  Tona Kunz

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