How Atomic Clocks Work

We live in an era when people are obsessed with the exact time. Our life is governed by a schedule, and our days are mainly composed of running from one side to another to arrive on time to a variety of things. Public transportation, office, education and even some of our entertainment throughout the day. The outstanding importance of exact time is undeniable, and it is this importance that leads to the creation and maintenance of atomic clock for pc desktop. With it, the GPS can work, the position of the planets can be calculated with sufficient accuracy for space exploration, and the Internet will always know the exact time. 

Creation of atomic clock standards

In fact, this value leads to the creation of several atomic clock standards. Today, three standards are used: the atomic clock of hydrogen, cesium and rubidium. This page focuses on the type of atomic clocks used by cesium 133 to measure the second.

atomic clock software

The cesium standard has become the main standard for measuring time in the modern world, while the International System of Units defines the second as “a duration of 9,192,631,770 radiation cycles corresponding to the transition between two energy levels of the atom of cesium-133 “. The reason for this is that the cesium atomic clock is still the most accurate for the longest period of time. It is believed that if any atomic clock made of cesium could work long enough, it will remain accurate for millions of years.

Although the word “radiation” is used, atomic clocks are not radioactive. They are not based on atomic decomposition to measure. In this sense, the energy is not released because the cesium atom is transferred between states. So, how exactly is the measurement made? 

First, all atoms have characteristic vibration frequencies

This means that all atoms repeat several states at regular intervals. In this particular case, it measures the state of energy between the negatively charged electrons and the charged charge. Different atoms have different oscillation frequencies based on the mass of the nucleus and the electrostatic “spring”, which leads to the fact that the opposite charges repel electrons when the gravitational pull of the nucleus approaches them. In short, “oscillation frequency” is the frequency with which electrons move back and forth as they revolve around the nucleus.

Even then, there is a variation between the energy states of the atom, so the atomic clock must be sure that cesium 133 has the correct oscillation frequency. To measure it accurately, a quartz oscillator must be connected to the main microwave resonance of the cesium 133 atom. This converts the atomic resonance of cesium into an atomic clock. By the way, the signal of the main microwave resonance is on the same frequency as the signals of direct satellite transmission.

To start the ticking of the clock, solid or liquid cesium is heated, so the atoms boil and go into a high vacuum tunnel. Upon entering the tunnel, they pass through a magnetic field that separates the atoms. Atoms that have the correct energy state pass through an intense microwave field.

The microwave energy within the field is transported between a narrow frequency range, crossing exactly 9,192,631,770 hertz in each cycle. The range always stays close to this frequency, since it comes from a crystal oscillator. When the cesium atom 133 receives microwave energy at exactly the correct frequency, it changes its energy state.

At the other end of the vacuum tube, the atoms collide with another magnetic field. This separates the atoms that are exposed to the exact frequency while they are inside the microwave field. These atoms reach the end and hit the detector.


The detector output reaches its peak when the microwave field is at the optimum frequency. This peak is used to make corrections in the crystal oscillator and to expand the microwave field, making sure it is exactly on the frequency.