Matches in DBpedia 2014 for { <http://dbpedia.org/resource/Atomic_fountain> ?p ?o. }
Showing items 1 to 32 of
32
with 100 items per page.
- Atomic_fountain abstract "An atomic fountain is a cloud of atoms that is tossed upwards by lasers in the Earth's gravitational field. If it were visible, it would resemble the water in a fountain. While weightless in the toss, the atoms are measured to set the frequency of an atomic clock.The primary motivation behind the development of the atomic fountain derives from the Ramsey method of measuring the frequency of atomic transitions. In broad strokes, the Ramsey method involves exposing a cloud of atoms to a brief radiofrequency (rf) electromagnetic field; waiting a time T; briefly exposing the cloud to the rf field again; and then measuring what fraction of the atoms in the cloud have transitioned. If the frequency of the rf field is identical to the atomic transition frequency, 100% of the atoms will have transitioned; if the frequency of the field differs slightly from the transition frequency, some of the atoms will not have transitioned. By repeatedly sending clouds of atoms through such an apparatus, the frequency of the field can be adjusted to match the atomic transition frequency.The precision of the Ramsey method can be increased by increasing the wait time T of the cloud. The use of an atomic fountain with a cooled atomic cloud allows for wait times on the order of one second, which is vastly greater than what can be achieved by performing the Ramsey method on a hot atomic beam. This is one reason why NIST-F1, a cesium fountain clock, can keep time more precisely than NIST-7, a cesium beam clock.".
- Atomic_fountain thumbnail Atomic_Fountain.jpg?width=300.
- Atomic_fountain wikiPageID "16899513".
- Atomic_fountain wikiPageRevisionID "573580226".
- Atomic_fountain hasPhotoCollection Atomic_fountain.
- Atomic_fountain subject Category:Atomic_physics.
- Atomic_fountain subject Category:Atoms.
- Atomic_fountain subject Category:Clocks.
- Atomic_fountain subject Category:Nuclear_technology.
- Atomic_fountain type Artifact100021939.
- Atomic_fountain type Clock103046257.
- Atomic_fountain type Clocks.
- Atomic_fountain type Device103183080.
- Atomic_fountain type Instrument103574816.
- Atomic_fountain type Instrumentality103575240.
- Atomic_fountain type MeasuringInstrument103733925.
- Atomic_fountain type Object100002684.
- Atomic_fountain type PhysicalEntity100001930.
- Atomic_fountain type Timepiece104437953.
- Atomic_fountain type Whole100003553.
- Atomic_fountain comment "An atomic fountain is a cloud of atoms that is tossed upwards by lasers in the Earth's gravitational field. If it were visible, it would resemble the water in a fountain. While weightless in the toss, the atoms are measured to set the frequency of an atomic clock.The primary motivation behind the development of the atomic fountain derives from the Ramsey method of measuring the frequency of atomic transitions.".
- Atomic_fountain label "Atomic fountain".
- Atomic_fountain label "نافورة ذرية".
- Atomic_fountain label "原子泉".
- Atomic_fountain sameAs 原子泉.
- Atomic_fountain sameAs m.0411lt7.
- Atomic_fountain sameAs Q4117649.
- Atomic_fountain sameAs Q4117649.
- Atomic_fountain sameAs Atomic_fountain.
- Atomic_fountain wasDerivedFrom Atomic_fountain?oldid=573580226.
- Atomic_fountain depiction Atomic_Fountain.jpg.
- Atomic_fountain isPrimaryTopicOf Atomic_fountain.