What Are X-Ray Phones?

X-ray ^[1] is an electromagnetic wave with extremely short wavelength and high energy. The wavelength of X-ray is shorter than that of visible light (about 0.001 to 10 nanometers. The wavelength of X-rays used in medicine is about 0.001 to 0.1 nanometers. Time), its photon energy is tens to hundreds of thousands of times greater than that of visible light ^[2] . Discovered by German physicist WK Roentgen in 1895, it is also called Roentgen ray.

The easiest way to generate X-rays is to hit a metal target with accelerated electrons. During the impact, the electrons suddenly decelerate, and the lost kinetic energy (1% of them) will be emitted in the form of photons, forming a continuous part of the X-ray spectrum, which is called braking radiation. By increasing the acceleration voltage and increasing the energy carried by the electrons, it is possible to knock out the inner electrons of the metal atom. As a result, holes are formed in the inner layer, and electrons in the outer layer transition back to the inner layer to fill the holes, while emitting photons with a wavelength of about 0.1 nm. Because the energy emitted by the outer electron transition is quantized, the wavelength of the emitted photons is also concentrated in some parts, forming a characteristic line in the X-ray spectrum, which is called characteristic radiation.

1. The tough radiation of electrons, bombard the metal with high-energy electrons, and the electrons decelerate sharply during the process of driving into the metal. According to electromagnetics, accelerated charged particles will radiate electromagnetic waves. If the electron energy is large, such as tens of thousands of electron volts, X-rays can be generated. This is the method currently used in laboratories and factories, hospitals and other places to generate x-rays.

2. The internal electron transition of the atom can also generate x-rays. The theory of quantum mechanics states that electrons radiate photons when they transition from high energy levels to low energy levels. If the energy difference between the energy levels is large, photons in the x-ray band can be emitted.

X-ray is an electromagnetic wave with extremely short wavelength and high energy. The wavelength of X-ray is shorter than that of visible light.) Its photon energy is tens to hundreds of thousands of times greater than that of visible light. ^[8]

X-rays have a certain degree of penetration of various substances, and the penetration strength is related to the wavelength of X-rays, the atomic number or density of the substance. It is because of the penetrability of X-rays that doctors can use X-ray machines, CT and other equipment to examine the patient's body ^[14] .

Due to the high energy of X-rays, after irradiation on the human body, it can cause cell damage, growth inhibition, and even destroy genetic material to cause canceration. This characteristic of X-rays can be used to kill some light-sensitive cancer cells in the human body, and it may also affect normal cells and induce health problems ^[14] .

Therefore, in terms of its essential properties, X-rays are indeed harmful to the human body. However, it is still the old saying, "Talking about toxicity without dosage is a hooligan." For example, ingesting 6 g of salt per day is not only harmless to the human body, but also a guarantee for the normal functioning of cells. But once long-term over-meter intake, the salt will become the accomplice of hypertension ^[14] .

According to the "Basic Standards for the Protection of Ionizing Radiation and the Safety of Radiation Sources" formulated by China, the incident dose of the X-ray machine should not exceed 10mGy in a single use; and according to media reports, the "weak photon human security device" at Chengdu Shuangliu International Airport once The radiation dose is controlled within 0.2 Sv (1Sv = 1000mSv = 1000000 Sv) ^[14] .

Therefore, if you receive an inspection of the security inspection device during the eleventh period, you don't need to worry about the amount of radiation, and it is not more than smoking a cigarette. ^[14]

However, due to the cumulative effect of X-rays, the use of security inspection equipment needs to be very cautious. If a small dose of X-rays can be encountered everywhere, there is a risk of unintended accumulation. Therefore, the Ministry of Environmental Protection of the People's Republic of China has sent a letter to the Sichuan Provincial Department of Environmental Protection, asking them to immediately stop illegal activities and ensure public safety for units that illegally produce, sell, or use X-ray human security equipment.

The truth: Although X-rays have the ability to cause harm to the body, if the radiation dose is very small, the occasional security check will not have a substantial impact on human health ^[14] .