| Canopus | |
|---|---|
 Canopusmushroom cloud | |
  Location of the test site | |
| Information | |
| Country | France |
| Test series | 1966–70 series |
| Test site | Fangataufa,French Polynesia |
| Coordinates | 22°13′40″S138°38′38″W / 22.22778°S 138.64389°W /-22.22778; -138.64389 |
| Date | 24 August 1968; 56 years ago (1968-08-24) |
| Test type | Atmospheric |
| Test altitude | 520 m |
| Device type | Thermonuclear |
| Yield | 2.6Mt (10878.4 TJ) |
| Test chronology | |
Canopus (orOpération Canopus) was thecodename of the firstFrenchtwo-stage thermonuclear test. It was conducted by the Pacific Carrier Battle Group (nicknamedAlfa Force) on 24 August 1968, at the Pacific Experiments Centre nearFangataufaatoll,French Polynesia.[1] The test made France the fifth country to test a thermonuclear device after theUnited States, theSoviet Union, theUnited Kingdom andChina. It was the most powerful nuclear device ever detonated by France.[2]
In 1966, France was able to usefusion fuel toboostplutonium implosion devices with theRigel shot.Robert Dautray (real name Ignatz Koushelewitz), a nuclearphysicist, was selected by theCEA to lead the development effort to construct a two-stage weapon. France did not have the ability to produce the materials needed for a two-stage thermonuclear device at the time, so 151 tons ofheavy water was purchased from Norway and an additional 168 tons from the United States. This heavy water went intonuclear reactors in 1967 to producetritium needed for the device.[citation needed]
France was to test the new device as part of a 5-shot series conducted at thenuclear testing grounds inFrench Polynesia. The device weighed three tons and used alithium deuteridesecondary stage with a highlyenriched uranium jacket primary.
Fangataufa was selected as the location of the shot due to its isolation in respect to the main base onMururoa. The device was suspended from a largehydrogen filledballoon. It was detonated at 18:30:00.5GMT with a 2.6megaton yield at an altitude of 550 metres (1,800 ft). Nominal yield was 2.6megatonnes of TNT (11 PJ) .[3] As a result of the successful detonation, France became the 5ththermonuclear nation.
A flotilla codenamed Alfa Force led by French aircraft carrierClemenceau deployed to the south Pacific during the time of the test. The naval force present around the two atolls massed more than 120,000 tons displacement and represented more than 40% of the tonnage of the entire French navy.[4]
The announcement by France in the late 1960s to test a hydrogen bomb provoked thePeople's Republic of China to conduct a full scale hydrogen bomb test of its own on 17 June 1967.[5]