Around the Lab
Moving the MCTC
June, 2002The Moving Cryogenic Target Cart (MCTC) is part of the Cryogenic Target Handling System (CTHS), an operation unique to LLE. LLE is the first laboratory worldwide to create a cryogenic target with a smooth surface, transport it to the OMEGA Target Chamber while maintaining a constant temperature and vacuum, and implode the target using inertial confinement fusion. The MCTC is crucial to this process. Essentially it is a transport mechanism, moving the target between the Fill/Transfer Station (FTS), the Characterization Station, and the OMEGA Target Chamber. This process is illustrated below.
Cryogenic Targets
Left: An “unlayered” plastic target containing frozen deuterium. Center: A partially layered target. This involves the ice plating on the inner surface of the plastic wall. Note the crystalline facet between the ice crystals. The bright ring is the inner surface of the ice shell. Right: A well-layered target. The hallmark of a well-layered target is the uniform radius of the bright band and the absence of crystal bounding facets. On each image, the faint black lines are spider webs. These webs are used to attach the approximately 1-mm target to a c-shaped holder or mount.
Moving the MCTC
The MCTC is positioned at the Characterization Station where the target is “layered,” a process that forms the hollow shell of frozen deuterium.
The MCTC, containing a layered target, is pulled away from the Characterization Station en route to an area underneath the target chamber. Air casters allow the 5,000-lb. cart to be easily maneuvered by the operators. Cables supplying air and power are attached to the MCTC to allow the cart to travel the approximately 200 ft along the corridors to an area below the OMEGA Target Chamber.
The MCTC is in the “airlock” space isolating Lab 157 from the building. The power and air utility lines are brought to the cart in preparation for transport down the corridor to beneath the Target Chamber.
The cart has been maneuvered down a corridor and through a second “airlock” to the area beneath the Target Chamber.
The MCTC is guided through La Cave to the Lower Pylon (upper right). The cart will be attached and the target will be transferred, in the Moving Cryostat, to the Target Chamber via the Lower Pylon.
The MCTC is attached to the Lower Pylon and the space between them is evacuated. The target and its accompanying cryogenic “life support” is then hoisted under vacuum to the center of the Target Chamber.