How are cathode rays produced ?
Cathode rays are produced through a process involving the application of high voltage to electrodes in a vacuum tube. Specifically, a cathode ray tube (CRT) begins the production of cathode rays with the emission of electrons from a heated cathode. When the cathode is heated, it releases electrons due to thermionic emission.
These electrons are then accelerated towards an anode (or positively charged electrode) within the vacuum tube when a high voltage is applied between the cathode and anode.
To make a cathode ray, a cathode ray tube (CRT) is typically used.
Inside the CRT, a vacuum is created to prevent electrons from colliding with gas molecules. A cathode, often heated to emit electrons, serves as the source of these electrons. When a high voltage is applied between the cathode and anode, electrons are accelerated towards the anode. The resulting electron beam, known as cathode rays, travels in a straight line from the cathode to the anode unless influenced by external electric or magnetic fields.
Cathode ray tubes (CRTs) are manufactured through a series of precise steps to ensure the production of a well-defined electron beam.
The process starts with the assembly of a glass vacuum tube containing electrodes, including a cathode and anode. The cathode, typically coated with a material that emits electrons when heated (thermionic emission), is heated to release electrons. These electrons are accelerated towards the anode by applying a high voltage across the electrodes.
Inside the CRT, the vacuum ensures that the electrons travel freely without colliding with gas molecules, allowing for the formation of a focused electron beam, or cathode rays.
Cathodes produce electrons through a phenomenon called thermionic emission.
When a material, such as tungsten or other metals, is heated to a sufficiently high temperature, electrons gain enough thermal energy to escape from the surface of the material. This emission of electrons from the cathode occurs naturally when the cathode is heated within a vacuum, as in cathode ray tubes (CRTs) and other electron-emitting devices.
In a Cathode Ray Oscilloscope (CRO), cathode rays are produced similarly to CRTs. The CRO’s cathode emits electrons when heated, and these electrons are accelerated towards a fluorescent screen by high voltage.
By varying the voltage, the beam’s position can be controlled, allowing it to create patterns on the screen.