Tuesday, June 26, 2012

Have a safe day!

Tuesday, June 26
Undergraduate Lecture Series - One West
Speaker: Brenna Flaugher, Fermilab
Title: The Cosmic Frontier: What We Can Learn from the Cosmos
3:30 p.m.
4 p.m.
Accelerator Physics and Technology Seminar - One West
Speaker: Milorad Popovic, Fermilab
Title: Staged Approach for 8-GeV CW Linac

Wednesday, June 27
3:30 p.m.
4 p.m.
Fermilab Colloquium - One West
Speaker: Samuel Kounaves, Tufts University
Title: The Mars Phoenix Mission: Simple Findings – Global Implications

Click here for NALCAL,
a weekly calendar with links to additional information.

Upcoming conferences


Take Five

Weather Sunny

Extended forecast
Weather at Fermilab

Current Security Status

Secon Level 3

Current Flag Status

Flags at half-staff

Wilson Hall Cafe

Tuesday, June 26

- Breakfast: Bagel sandwich
- Creamy turkey vegetable soup
- Chili dog
- Country fried steak
- Chicken cacciatore
- Italian panini w/ provolone
- Assorted calzones
- Southwestern chicken burrito

Wilson Hall Cafe Menu

Chez Leon

Wednesday, June 27
- Spring-roll salad w/ red-curry shrimp
- Lemon Napoleon

Friday, June 29
- Warm fennel salad
- Lobster tail w/ lemon butter sauce
- Spaghetti squash w/ scallions
- Grilled asparagus
- Blueberry tartlets w/ lime curd

Chez Leon Menu
Call x3524 to make your reservation.


Fermilab Today

Director's Corner

Result of the Week

CMS Result

Physics in a Nutshell

Tip of the Week

User University Profiles

Related content


Fermilab Today
is online at:

Send comments and suggestions to:

Visit the Fermilab
home page

Unsubscribe from Fermilab Today


Fermilab's new cavity temperature mapping system commissioned

Temperature-mapping sensors are placed around a single-cell niobium cavity to find spots where energy is dissipated. Photo: Alexander Romanenko

Fermilab scientists have a new diagnostic tool that could lead to far more efficient accelerator cavities.

A team in the laboratory's Technical Division, led by scientist Alexander Romanenko, recently completed and commissioned a custom-made temperature-mapping system to be used on superconducting cavities. With the new tool, one of only three such in the world, scientists may be able to get to the bottom of the problem of why superconducting cavities dissipate much more energy than theory predicts.

It's a problem that researchers have addressed largely using trial-and-error methods. But by measuring the varying temperature over the surface of the cavity, the new system can pinpoint hot spots in the cavity wall, culprit sites that cause anomalous energy dissipation. Understanding how and why the dissipation happens provides an invaluable insight into the governing physics, which is still not understood.

"Before, we couldn't do the same level, or even a comparable level, of fundamental research on cavities as places such as Cornell or Jefferson Lab because, without a system like this, the cavity's basically a black box," Romanenko said.

"You'd see from the data that there was energy loss, but you wouldn't know where," said TD scientist Anna Grassellino. "Now we can detect the heating patterns in the cavity walls and use them to identify the different loss mechanisms."

The system comprises 576 sensors placed closely together all around a 1.3-gigahertz cavity cell. Each sensor takes the temperature reading for a square centimeter of cavity wall. An exceptionally high reading points to the site of energy dissipation. Scientists can then remove the lossy piece of cavity wall and try to learn how that particular area is different from the rest.

The project is part of an effort to raise superconducting cavities' so-called quality factor, or Q. The higher the Q, the less energy the cavity loses, the less power it needs to propel particles.

Tests show that the quality factor increases or decreases depending on the cavity's electromagnetic field strengths, though in principle it shouldn't. Researchers don't fully understand the reason for the sloping Q, or more importantly, how they can prevent Q from sloping downward, leading to energy loss.

Read more

Leah Hesla

Red spots in the temperature readout of a single-cell niobium cavity indicate places on the cavity where energy was dissipated. Temperature mapping was developed in the 1970s at Cornell University, where Romanenko completed his dissertation on a related topic in 2008. Last year he and his team learned how to build their own system from researchers at Jefferson Lab. They spent one year custom-building each sensor, finally commissioning the system last April.
Special Announcement

Birds, Butterflies and More - today

From noon to 1 p.m. today, stroll though transitional habitat along the Margaret Pearson Interpretive Trail. Enjoy learning from experts and looking up, down and all around. Meet at the Prairie Interpretive Trail on westbound Pine Street.

In the News

Higgs rumors: fun for you, dangerous for me

From The Guardian, June 23, 2012

CERN have just announced that there will be a seminar on the 4th of July, at which an update on the search for the Higgs boson will be given. We've been collecting collisions for the last few months, up until last Monday, and hopefully we will manage to analyse them to look for signs of the Higgs (via at least a couple of the ways it might decay).

The rumour-mill has been running for a while, of course. The #higgsrumors hashtag (US spelling!) even trended on twitter for a while yesterday. All very entertaining for the neutrals, and I am pleased that we're not the only ones interested in and excited by our experiment.

Read more
Director's Corner

The Physics Advisory Committee

Fermilab Director
Pier Oddone

The June retreat with our Physics Advisory Committee took place last Tuesday through Saturday. In these yearly meetings the PAC, laboratory leadership and representatives from DOE and NSF get together for a detailed review of the laboratory's program and plans for the future. It is an intense retreat with long hours of presentations and discussions and numerous writing assignments. We also hear presentations on new ideas that are submitted through letters of intent and formal proposals. This year we discussed three letters of intent and one proposal, a clear sign that the creativity of our community continues unabated.

The PAC is a great committee. We are very fortunate that it includes an outstanding group of physicists from across the country and abroad. The discussions at the retreat are carried out in depth and we all learn an enormous amount of physics over the course of the meeting.

An important discussion at this year's retreat concerned the reconfiguration of the Long Baseline Neutrino Experiment. The pros and cons of the three viable options developed by the Steering Committee were discussed in detail. The reconfiguration of LBNE is an important opportunity because DOE is supporting us to continue in a phased approach along the plans developed by the community through the P5 panel of HEPAP—plans that have been accepted by the DOE and Congress.

The PAC's advice helps us shape the program of the laboratory. There are always many good ideas, but not all of them can be implemented in the present budget environment. At the conclusion of each year's retreat we share the committee's written report with the community. Subsections of the report are written before the retreat ends, with the full report pulled together in the following days. It is not posted immediately so that proponents of various activities and programs can be notified first of the conclusions and recommendations. In a few days you will be able to read the report from a link on the PAC website.

I want to thank Jeff Appel for his outstanding work in organizing the PAC meetings over the years. Jeff will be retiring next month and we will miss his meticulous work in the many tasks that he carries out for the laboratory, also reflected in the great quality of the PAC meetings he has organized.

Fermilab's Physics Advisory Committee. Click to enlarge. Photo: Fermilab
Photo of the Day

Kathryn and Zachary Jepsen

Fermilab's Kathryn Grim, now Kathryn Jepsen, married Zachary Jepsen in Cincinnati, Ohio, on May 26. Kathryn is a senior communications specialist at Fermilab and serves as the deputy editor of symmetry magazine. Zachary is a logistics officer in the U.S. Marine Corps. Photo: Shelby Street Photography

Latest Announcements

QuarkNet fellows virtually visit CERN - June 27

Louisiana Roots Band and Red Stick Ramblers - July 14

Volunteers invited to Fermilab prairie quadrat study - today, July 12 and 28

After-hours shuttle trial extended through June

Creation's Birthday: a new play about Hubble and Einstein - July 5

Collider New Play Project - July 7, 14 and 21

On-site housing requests for fall 2012 and spring 2013 - through July 16

Circuit design applications w/ National Instrument's multisim course - July 19

Project Management Introduction class - July 23-27

Fermilab Management Practices Seminar - begins Oct. 4

Interpersonal communication skills training - Nov. 14

Outdoor soccer - Tuesdays and Thursdays at 6 p.m.

Pool memberships available

Fermilab employee discounts

Security, Privacy, Legal  |  Use of Cookies