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CDMS photos and videos

When publishing any of the photos and videos on this page please credit them to Fermilab unless noted otherwise. Download larger images by right clicking on the thumbnails or the "Larger Image" links.

In these figures, the dotted red line divides events into those determined not to be WIMPs based on the relative timing of the heat to charge signals (left side) and those that could potentially be WIMPs based on that parameter (right side). The solid red box delineates the area of the graph in which WIMPs should occur based on both timing and the heat to charge ratio. Two events in separate detectors demonstrated the characteristics scientists predicted a WIMP would have.
Credit: CDMS.
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The curves dipping through this figure represent the results of several dark matter search experiments. The vertical scale represents the rate of WIMP scatters with nuclei while the horizontal scale is the mass of the WIMP. The gray line represents the 2008 results from the CDMS experiment. The blue line represents the most recent CDMS results. The solid black line represents the two results combined. The dotted black line represents the curve the combined results would have formed if CDMS had found no candidate events in 2009. The green and gray backgrounds represent areas that two theories of supersymmetry predict would contain dark matter.
Credit: CDMS.
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Dark matter detectors. The Cryogenic Dark Matter Search experiment uses five towers of six detectors each.
Credit: Fermilab.
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Dan Bauer, CDMS project manager and Fermilab scientist, removes one tower of detectors used in the Cryogenic Dark Matter Search experiment.
Credit: Fermilab.
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Scientists of the Cryogenic Dark Matter Search experiment are listening for whispers of dark matter. Inspired by his brother Erik's research, musician Karl Ramberg built a musical model of the CDMS detector, in collaboration with CDMS scientists. Erik Ramberg and Priscilla Cushman translated real CDMS data into a format that accurately converts the energy, location and type of particles striking the CDMS detectors into sound and light. Cushman created this 5-minute video.
Credit: Priscilla Cushman.
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Closeup of a CDMS detector, made of crystal germanium.
Credit: Fermilab.
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This video (1 min.) shows a time lapse of the construction of the CDMS experiment in 2003-2004.
Credit: CDMS collaboration.
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The CDMS detectors, made of germanium, are located inside an ice box. A fridge provides the coolant to keep the detectors at close to absolute zero. Shielding material around the icebox minimizes the number of cosmic rays and other background particles that hit the detectors.
Credit: CDMS collaboration.
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The CDMS experiment has achieved the world’s most stringent limits on how often dark particles interact with ordinary matter and how heavy they are, in particular in the theoretically favored mass range of more than 40 times the proton mass (about 40 GeV/c2). The regions excluded are those above the solid lines. The black line is the most stringent limit. The bottom axis indicates the WIMP mass and the left axis refers to the frequency with which WIMPs interact with ordinary matter.
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Detector Closeup of a detector in its mount. A detector of this kind, made of Silicon, was operated in the 1998 run. The photolithographically-fabricated thin film on the surface is the phonon sensor and represents a significant advance over the detectors used in the 1999 run. Silicon and germanium detectors, weighing 100 g and 250 g respectively, are used in CDMS II runs in the Soudan Mine.
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Tower Project manager Dan Bauer from Fermilab holds one tower of detectors as Vuk Mandic, now at the University of Minnesota, examines them. Each tower of detectors contains 1 kilogram of germanium for detecting dark matter and 200 grams of silicon to distinguish WIMPs from neutrons. Thin layers of silicon, aluminum, and tungsten covering the detector surfaces measure both the heat and charge released when a particle interacts inside.
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Two Towers A view of the inner layers of the cryostat with two towers installed. Detector towers are mounted in the holes covered by hexagonal plates. The coldest part of the cryostat stays at 10 mK (millikelvin, or thousandths of a degree above absolute zero) during operation. The surrounding layers are higher temperature stages of the cryostat. The cryostat is constructed using radiopure copper to provide a low-radioactivity environment for the extremely sensitive CDMS detectors.
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Cryostat Shielding A scientist examines the shielding around the cryostat.
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Arrival The first detectors arrive at the Soudan Mine on February 21, 2003.
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CDMS collaboration A collaboration meeting at Soudan in March, 2003. The 12-institution collaboration includes 45 scientists.
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Soudan elevator The Soudan Underground Mine was closed in 1963 and placed on the National Register of Historic Places in 1966. It is operated as a State Park by the Minnesota Department of Natural Resources, with 14 tours a day taking the historic elevator for a fast and clamorous ride nearly a half-mile below the surface. After descending, hard hat-wearing tourists can view old mine caverns with some of the equipment still standing in place. Since May 2002, tourists can also view the cavern housing the CDMS detector.
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Soudan aerial Soudan is part of Minnesota's Iron Range. Rich ore deposits were discovered in the area in 1865. Today, underground mines have largely given way to surface mining. The Soudan Underground Mine has served as a physics laboratory since 1979. The photo shows the view from the top of the tower above the Soudan Mine shaft.
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last modified 12/22/2009   email Fermilab