It is an atomic clock that uses an atom to keep track of time. Atomic clocks use certain atoms known to be completely stable in the rate of ticking. The electronic components of atomic clocks are regulated by the frequency of microwave electromagnetic radiation. Only when the radiation is maintained at a precise frequency will it induce specific electronic changes. The frequency of the radiation will be periodically adjusted to keep the atom in its ground state at a constant temperature. For example, radiation of the microwave frequency 2 GHz will cause changes in the electronic components of atomic clocks. When the electronic components undergo specific changes to maintain an exact frequency of microwave radiation, it is called the forcing process and called the phase-locking process.
The first atomic time clock was created in 1949. The first version used a mercury-vapor atomic clock, which is a type of atomic clock that uses gas with atoms that have at least one electron removed. The first atomic clock was called NBS-1. The name referred to the National Bureau of Standards, now known as the National Institute for Science and Technology. In 1955, the United States Department of Defense started creating atomic clocks that were accurate to one second in a year. The atomic clock, which uses an electronic transition frequency in the electromagnetic spectrum of an atom, is the most accurate means of maintaining time possible.
Despite its name, it is not radioactive. Due to its accuracy, the atomic clock was developed in response to the requirement for a time standard that would allow radio stations to remain on their designated frequency. Atomic clocks are used as the significant international time standard because they keep better time than the movement of stars and the earth’s rotation.
Working Principle of an Atomic Clock
An atomic clock consists of an electric field generated by a microwave generator placed in a large electric field containing many coils. Because an electric field is generated, electric charges are separated by it. The earth’s magnetic field is used to keep the charges separated to keep them apart. This magnetic field has two components, one horizontal and the other vertical. Each of the two magnetic field components is directed in a different direction.
The earth’s electric field generates an electrical side-chain field (or drift). The electric side-chain current comprises the horizontal and vertical components of the earth’s magnetic field. The electric side-chain current moves through a coherent coil. The side chain current is led through the conductors of a coherent coil, which is a set of copper wires. The second type of microwave generator, called a quasi-coherent generator, was developed before atomic time clocks were invented. This type of microwave generator can separate the components.
It uses electromagnetic radiation as an oscillating signal to keep the charges separated. The oscillation of the radiation that oscillates in the horizontal direction is called horizontal, and the oscillation in the vertical direction is called vertical. The separation of charges using electromagnetic radiation is known as EM radiation. The phase shift of EM radiation is created by a phase-locked loop (PLL). The phase-locked loop consists of two identical coils, six capacitors, one inductor, one diode, and two resistors. The case consists of a microwave generator, which produces EM radiation whose frequency can be adjusted to achieve exact frequencies. The components of the phase-locked loop are placed in a vacuum. The two loops are made using wire and a ceramic substrate, then baked to solidify them. The vertical and horizontal components are attached to the sides of the atomic clock by metal wires.
Atomic Clock Accuracy
Atomic clock accuracy is 0.1 second in one billion years. Over time, the phase-locked loop does not keep a phase relationship between the horizontal and vertical components of the electromagnetic radiation produced by the microwave generator, causing a frequency error of up to 10 seconds per day. It is necessary to feed it with a reference frequency which can be achieved by adding a crystal oscillator to the controlled circuit of an atomic clock to keep the phase-locked loop in synchronization.
Atomic clocks are incredibly accurate. Atomic clocks are accurate to a million times, which is better than any other earth-based clock.