By Kelly Stifter
The author (l) at work in the LZ lab with UMASS student Chris Nedlik. (Credit: Steffan Luitz.)
Ever wanted to learn about dark matter—the elusive particle that holds galaxies and galaxy clusters together? What about dark energy—the mysterious force that is causing our universe to expand at a continually increasing rate? If so, you’re in luck!
After a several-year interim, free public tours returned to SLAC in April 2016. Our guides are a collection of experienced staff members and passionate graduate students—myself included! I’m looking forward to sharing my work as a part of the tour program as I work towards my Ph.D. in Physics. You know what they say: you don’t truly understand something until you can explain it to others.
KIPAC graduate student Kelly Stifter leading a tour of SLAC National Accelerator Laboratory. (Credit: SLAC National Accelerator Laboratory.)
And now, after much planning and preparation, the tour program is excited to bring you to a whole new stop on SLAC public tours! In addition to a 20 minute video on SLAC’s history and current work, as well an old favorite, SLAC’s 2 mile-long accelerator, visitors now get to see two KIPAC experiments that are probing the “dark sector,” the name given to dark matter and dark energy, the unseen matter and unexplained force that are keeping a lot of scientists up at night.
First, you’ll learn about the Large Synoptic Survey Telescope (LSST). SLAC is responsible for building the camera for this telescope, and you’ll get to see a 3D movie, as well as the clean room where all the action happens. Once built, the camera will be the largest digital camera in the world, sporting a whopping 3.2 BILLION (with a "B") pixels, and will produce the widest and deepest view of the night sky ever. The results from this experiment will help us probe deeper into the mysteries of dark energy, which makes up about 70% of the entire mass-energy budget of the Universe.
Tour members check out the cleanroom in which the giant camera for the Large Synoptic Survey Telescope is being assembled. (Credit: SLAC National Accelerator Laboratory.)
Next, you’ll learn about the LZ experiment, which is trying to directly detect the dark matter that accounts for about 25% of all energy in the universe. The results from this experiment could either definitely prove the existence of dark matter by seeing it interact right here on Earth, or it could place the most precise limits on its mass and cross-section to date. I’m particularly excited about this addition to the tour program, because this is the experiment that I work on! It will use a giant tank of the noble gas xenon, cooled to a liquid state, to look for dark matter particles. My work focuses on LZ’s System Test, which is a scaled-down version of the LZ detector. This work will inform the final design of the LZ detector, and will also help to make sure that everything goes smoothly when the experiment is turned on in 2020.
SLAC’s Thomas “TJ” Whitis at the test stand for the LZ experiment at SLAC. The TPC prototype is installed inside the cylinder on the left. (Credit: SLAC National Accelerator Laboratory.)
And if the new stops weren’t already enough of a temptation, you can also visit one of the few non-public Starbucks in the world while on the SLAC campus, and even press your own SLAC souvenir penny.
Did I mention the tours are FREE?
Are you ready to sign up yet? Public tours occur one Friday a month, at 1 pm and 2:30 pm. Tickets "sell out" very quickly, so I recommend registering as soon as they are available! For more information, please visit our public tour page. Come on by and see what we’re up to!