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LIGO Livingston Observatory NewsEighth LSC Meeting Convenes in Louisiana
Passing Milestones: The Third Engineering Run at Livingston
A Journey Through Light
Engineering runs are the milestones of the LIGO commissioning effort, each of them proving the sturdiness of our detectors as they approach their final sensitivity. During these highly collaborative endeavors, we are always directed toward multiple and diverse goals. With each run, we bolster our confidence and aptitude by achieving solid "up-times" for the detector, while focusing on collecting the best data possible. Engineering runs also provide a great opportunity to gather LIGO Lab and LSC scientists from all over the world at a place where they have the chance to work together, gaining hands-on experience with the detector, and building professional and personal ties. We consider this community-building mission to be on equal terms with the technical challenges, since a tight working kinship is one of the important factors determining our future achievement.
Above: At left, LSC scientists discuss detector operations during the Third Engineering Run (E3) at the Livingston Observatory. Then at right, scientists in the control room probe the detector to ensure proper operation and to plan the best course of action to fix minor problems.
The Third Engineering Run (E3) was conceived as an important milestone in LIGO's development, since this was to be the very first engineering run for the Livingston Observatory, as well as the first time we would attempt to smoothly run both Hanford and Livingston detectors simultaneously. Then, shortly before the planned start of the run, we received the discouraging news here at Livingston about the setbacks to the Hanford interferometer caused by the recent Washington earthquake. In spite of this dispiriting news we did not lose our enthusiasm, and made the right decision to forge ahead with the run as planned. Of course we had to accept the limitations of reality, facing the fact that we would make coincident observations only on the Physical Environmental Monitoring channels. Still, these would provide us with the first chance to study site-to-site coincidences and correlations, and to try to merge data in real time from the two observatories.
The E3 run was a definite success. In its first three days we achieved 85 percent up-time using the X-arm of the Livingston 4-Km interferometer, and close to 100 percent on the fourth day. We collected various datasets amounting close to 1.5 TB and achieved high overlap time with the Hanford Observatory.
Above: (Left) Scientists at work in the computer room, making sure the recorded data is of good quality. (Right) Good-spirited operators of a locked interferometer.
More than 13 scheduled scientific investigations collected data during E3. The enthusiastic operators, scientific crew and observers in the control room closely monitored the detector 24 hours a day to ensure flawless data acquiring. E3 attracted more than 20 LSC scientists to take part in the run, most of them having the chance to be on shifts, and to diagnose and assist in the troubleshooting of operational functions.
It was a great time for everyone present, and I would like to thank the laboratory staff for their hard work which made this run possible, the operators for their patience and attention which kept us up and running, and the scientists on site who ensured good-quality data! Special thanks too to Mark Coles (pictured at left below), head of the Livingston Observatory, who found time despite his many duties to treat us to his excellent lunches (below right), a bounty we all thoroughly enjoyed!
Of course, the run was just the beginning of the fun! Now it's time to look at the data! You can follow our progress on the E3 homepage, where you can find the data from and results of the investigations. As a little "sneak preview," the two graphs at left and right below show some preliminary results from the run.
Above: At left, tidal effects on the common mode control signal. The red curve shows the raw control signal while the blue segments show the reconstructed tidal variation using multiple lock stretches. Each red segment corresponds to a long locked period while the end of each segment signals a lock loss, often due to tidal shifts. Then, at right, timing delay between the second tic of the GPS clock and the time stamp of the recorded data. We observed small timing jumps associated with DAQ reboots. The graph also shows that the timing difference was less than 100µs between the two observatories during the run. The relative delay can be easily corrected by using this timing data.
Three participants from LIGO--Bonnie Wascom and Rusyl Wooley from the LIGO Livingston Observatory, and Dr. Rainer Weiss from MIT-LIGO--joined a host of other guest speakers in leading the children of St. Bernard School in A Journey Through Light, which was the theme of this year’s Annual Science Symposium.
The children began their journey with educational field trips to various locations the week before the symposium. Each field trip centered around a location in which light plays a key role in the operation of that particular facility. The 5th and 6th graders visited the LIGO Livingston Observatory, and their tour concentrated on the use of laser light in the study of gravitational waves. To commemorate their visit, the children painted light houses like the one erected in front of their school, as well as light bulbs on our tunnel of fame.
Pictured Above: (1) Fifth Grade snapshots. (2) Light house painting. (3) Actual light house in front of school. (4) Light bulbs painted on the tunnel of fame.
The symposium dawned with a boat ride for honorees down the bayou that runs along side the school, followed by a blessing of the event for the parochial school. Honorees included the sheriff; the mothers who coordinated the symposium; and Dr. Rainer Weiss, the keynote speaker. Halos glowed (with mischief) and faces shinned (with curiosity) as the children entered the gym to hear Dr. Weiss speak. After being shown that it was not possible to squeeze light by looking through squeezed fingers, and then observing that the largest amount of light from a bulb is not visible, Dr. Weiss produced a strange apparatus which made an indiscreet noise that immediately broke the ice with the children. Demonstrating the wiggle direction of light was then a piece of cake for Rai, pictured at right. (Of course, all of us who know Rai knew it would not be difficult for him to reach these youngsters.)
The children’s shining adventure continued over the next several days as Rai visited each class individually (K-8) and conducted experiments centering around the properties of light, in particular polarization. Following Dr. Weiss, Bonnie and Rusyl continued the discussion on properties of light by conducting hands-on experiments with each class, in particular of the electromagnetic spectrum. The LIGO slinky was as illuminating as Dr. Weiss’s strange apparatus when it came to learning about light waves, and many children also enjoyed the cool rainbows in the spectrometers.
Above: (1) Rai Weiss demonstrates to the class. (2) Bonnie Wascom enlightens. (3) Rusyl Wooley instructs. (4) Rusyl illustrates with the LIGO slinky. (5) Children observe through spectrometers.
Besides the LIGO speakers, the symposium offered 16 other guest speakers who visited each class, including a photographer, a meteorologist, an artist, an eye doctor, puppeteers, a candle maker, an agronomy professor from LSU, and representatives from the Department of Transportation and the electric company, to name a few. The speakers' presentations ranged from shadow puppetry workshops, to electrical safety, the sun and the seasons, light and vision, light as art, and various discussions on the importance light plays in our everyday lives.
Special features to brighten the conclusion of the journey included an excursion through the Sylvania LIGHTmobile® and an exploration through the "Illumination Station." The Sylvania LIGHTmobile® is a 66-foot, 18-wheeled tractor trailer, state-of-the-art, hands-on training facility used to provide businesses with the latest information in lighting technology, energy conservation and design, as well as energy management computer program systems. The Illumination Station was a light museum set up in the gym by some of the students' parents. The museum contained displays, information, and work stations touching on topics such as the history of light bulbs; Einstein; kaleidoscopes; optical illusions; lasers and infrared; stars; magic shows using mirrors and light; shadow walls; microscopes; telescopes; and more.
Shown Above: Exhibits on (1) the history of light bulbs, (2) and Albert Einstein. Budding scientists peer through (3) kaleidoscopes, (4) and microscopes, (5) and generally enjoy the museum's displays.
The week-long symposium was featured in all the local newspapers, radio and news stations. It was obviously a big event for the city of Breaux Bridge, Louisiana. We at LIGO were delighted by the many questions and overwhelming level of participation from all the children (except perhaps the 8th graders who had to pretend to be way too cool to admit any interest). We were also impressed with these parents who encouraged their children's involvement in science, as shown by their time and effort, and the amount of preparation they took in making the symposium a success. As the event drew to a close, we thanked the symposium mothers for their hospitality and for letting us be a part of this year’s journey. We also left some of the teachers with materials and information on properties of light, urging them (along with some of the school administrators) to continue the exposure and interest in science that the children had been introduced to during the symposium. To view a complete set of photos taken during the week, click here.