Tuesday, March 3, 2015
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Have a safe day!

Tuesday, March 3

10:30 a.m.
Research Techniques Seminar - Curia II
Speaker: Jean-Francois Pratte, University of Sherbrooke
Title: Single Photon Avalanche Diodes' Readout Electronics for Particle and High Energy Physics Experiments and Positron Emission Tomography Imaging

3:30 p.m.
Director's Coffee Break - WH2XO

THERE WILL BE NO ACCELERATOR AND PHYSICS TECHNOLOGY SEMINAR THIS WEEK

Wednesday, March 4

3:30 p.m.
Director's Coffee Break - WH2XO

4 p.m.
Fermilab Colloquium - One West
Speaker: Timothy Cohen, Princeton University and the Institute for Advanced Study
Title: The Higgs Mass, Top Partners, and the LHC

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Wilson Hall Cafe

Tuesday, March 3

- Breakfast: all-American breakfast
- Breakfast: bacon, egg and cheese bagel
- Ranch chicken breast sandwich
- Pork piccata with lemon sauce
- Polish cabbage roll
- California turkey panino
- Shrimp and crab scampi
- Minnesota chicken and rice soup
- Chef's choice soup
- Assorted pizza by the slice

Wilson Hall Cafe menu

Chez Leon

Wednesday, March 4
Lunch
- Chipotle marinated pork tenderloin with pineapple salsa
- Green rice
- Margarita cake with key lime cream cheese frosting

Friday, March 6
Dinner
- Avgolemono soup
- Herb-crusted lamb chops
- Horseradish mashed potatoes
- Steamed broccoli
- Baklava

Chez Leon menu
Call x3524 to make your reservation.

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Feature

Detecting something with nothing

From left: Jason Bono (Rice University), Dan Ambrose (University of Minnesota) and Richie Bonventre (Lawrence Berkeley National Laboratory) work on the Mu2e straw chamber tracker unit at Lab 3. Photo: Reidar Hahn

Researchers are one step closer to finding new physics with the completion of a harp-shaped prototype detector element for the Mu2e experiment.

Mu2e will look for the conversion of a muon to only an electron (with no other particles emitted) — something predicted but never before seen. This experiment will help scientists better understand how these heavy cousins of the electron decay. A successful sighting would bring us nearer to a unifying theory of the four forces of nature.

The experiment will be 10,000 times as sensitive as other experiments looking for this conversion, and a crucial part is the detector that will track the whizzing electrons. Researchers want to find one whose sole signature is its energy of 105 MeV, indicating that it is the product of the elusive muon decay.

In order to measure the electron, scientists track the helical path it takes through the detector. But there's a catch. Every interaction with detector material skews the path of the electron slightly, disturbing the measurement. The challenge for Mu2e designers is thus to make a detector with as little material as possible, says Mu2e scientist Vadim Rusu.

"You want to detect the electron with nothing — and this is as close to nothing as we can get," he said.

So how to detect the invisible using as little as possible? That's where the Mu2e tracker design comes in. Panels made of thin straws of metalized Mylar, each only 15 microns thick, will sit inside a cylindrical magnet. Rusu says that these are the thinnest straws that people have ever used in a particle physics experiment.

These straws, filled with a combination of argon and carbon dioxide gas and threaded with a thin wire, will wait in vacuum for the electrons. Circuit boards placed on both ends of the straws will gather the electrical signal produced when electrons hit the gas inside the straw. Scientists will measure the arrival times at each end of the wire to help accurately plot the electron's overall trajectory.

"This is another tricky thing that very few have attempted in the past," Rusu said.

The group working on the Mu2e tracker electronics have also created the tiny, low-power circuit boards that will sit at the end of each straw. With limited space to run cooling lines, necessary features that whisk away heat that would otherwise sit in the vacuum, the electronics needed to be as cool and small as possible.

"We actually spent a lot of time designing very low-power electronics," Rusu said.

This first prototype, which researchers began putting together in October, gives scientists a chance to work out kinks, improve design and assembly procedures, and develop the necessary components.

One lesson already learned? Machining curved metal with elongated holes that can properly hold the straws is difficult and expensive. The solution? Using 3-D printing to make a high-tech, transparent plastic version instead.

Researchers also came up with a system to properly stretch the straws into place. While running a current through the straw, they use a magnet to pluck the straw — just like strumming a guitar string — and measure the vibration. This lets them set the proper tension that will keep the straw straight throughout the lifetime of the experiment.

Although the first prototype of the tracker is complete, scientists are already hard at work on a second version (using the 3D-printed plastic), which should be ready in June or July. The prototype will then be tested for leaks and to see if the electronics pick up and transmit signals properly.

A recent review of Mu2e went well, and Rusu expects work on the tracker construction to begin in 2016.

Lauren Biron

In the News

Elusive 'dark photons' still lurking in the shadows

From Live Science, Feb. 27, 2015

A giant atom smasher has found no trace of a mysterious particle called the dark photon.

The elusive subatomic particle — a heavier, dark twin of an ordinary particle of light — could help explain how dark matter, the shadowy hidden mass in the universe that holds galaxies together, interacts with regular matter.

The new result doesn't rule out the existence of the dark photon. But it does mean physicists must come up with a new explanation for puzzling experimental results that contradict the most dominant theory of physics.

Read more

Director's Corner

Reviews help our plans for great science

Fermilab Director
Nigel Lockyer

Reviews are a part of our everyday life at Fermilab. We executed over 250 internal and external reviews, assessments and inspections in 2014. That's almost one for every business day of the year. Perhaps this number is not surprising to many of you. Although a significant burden on the lab staff, reviews help us ensure that we are carrying out our science efficiently and safely. Reviews often include outside experts, giving us an opportunity to "learn from the best." And they provide regularly scheduled opportunities for us to hone our strategic planning at all levels, from individual offices to projects to the lab as a whole.

Last month's DOE Institutional Review provided an excellent opportunity for us to showcase our recent strides in strategic planning. A team of 22 people from DOE, other labs and universities spent four days delving into our lab from the perspective of five areas: CMS, the cosmic frontier, neutrinos, muons and technology R&D. Unlike many reviews that are narrowly focused, this once-every-three-years review evaluates the entire lab's scientific program and support structures to ensure that we are well coordinated and synergistic.

This was a very successful review, as evidenced by excerpts from the closeout:

"The lab is aligned very well to P5 priorities and following P5 recommendations. There is palpable excitement for the recent positive developments in securing international support for the long-baseline neutrino program. Fermilab has long been the focal point for high-energy physics in the United States. The lab should strive to maintain this role."

As always, the review identified some opportunities for improvement that we will follow up on in the coming years. This review took months to prepare for, and Joe Lykken, Erik Gottschalk and a 25-member team did a great job in developing and telling the lab's story from the perspective of the DOE's five areas.

And of course the review work is never done. The senior leadership and financial teams have spent the last few weeks preparing a refined 10-year strategic plan for tomorrow's budget briefing to the Office of High Energy Physics. This will be another opportunity for us to present our plans for the future, which are more focused than ever. We look forward to the feedback.

Photos of the Day

Crystal pattern

If you happened to walk by Kidney Pond earlier this month, you may have noticed large ice crystals covering the area. Photo: Don Cossairt, ESH&Q
The crystals formed eye-catching patterns. Photo: Don Cossairt, ESH&Q
The crystals were about two inches long. Photo: Don Cossairt, ESH&Q
Announcements

Today's New Announcements

Fermilab Wi-Fi maintenance - today

Garden Club spring meeting - March 5

Deadline for University of Chicago tuition remission program - March 6

Deadline approaches for summer on-site housing requests - March 9

NALWO Puerto Rican cooking demo - March 9

Lab-Corps program accepting applications until March 13

10-minute employee appreciation chair massages - March 17

URA Thesis Award competition deadline - March 20

Managing Conflict on March 24

URA Visiting Scholars Program deadline delayed to March 30

2015 Alvin Tollestrup Award application deadline - April 1

Need cash for college? Abri is awarding two $1,000 scholarships

Yoga signup due soon

Fermilab Golf League 2015 season is just around the corner

Scottish country dancing Tuesday evenings at Kuhn Barn

International folk dancing Thursday evenings at Kuhn Barn

Indoor soccer