The first object of radiation protection equipment is: α - ray alpha particle is the nucleus of helium-4 with high energy. Due to the Coulomb field effect and elastic collision, the energy of alpha particles is often consumed to absorb other substances. Therefore, the protection against radiation is relatively simple, and a piece of paper can basically prevent it. However, it does great harm to people in close range. Alpha particle internal irradiation will consume all the energy in a short distance, so it damages the cells and tissues exposed to short distance irradiation seriously.

射線防護(hù)器材之防護(hù)對(duì)象二：β射線 β粒子實(shí)質(zhì)是高速運(yùn)動(dòng)的電子束，帶有一個(gè)負(fù)電荷(對(duì)正電子是一個(gè)正電荷)，質(zhì)量為質(zhì)子或中子的1/1837。β射線的穿透能力一般，介于α、γ射線之間。

Protection object 2: beta ray beta particle is essentially a high-speed moving electron beam with a negative charge (a positive charge to a positron), with a mass of 1 / 1837 of a proton or neutron. The penetration ability of β - ray is between α - ray and γ - ray.

由于β射線與原子量較大的物質(zhì)作用時(shí)容易產(chǎn)生軔致輻射，所以對(duì)于活度較大的β放射源，一般會(huì)選擇有機(jī)玻璃等輕質(zhì)材料進(jìn)行防護(hù)，然后再選擇原子量較大的物質(zhì)進(jìn)行屏蔽。對(duì)β射線的防護(hù)既要考慮內(nèi)照射，又要考慮外照射。

Since bremsstrahlung is easy to be produced when β - ray interacts with substances with large atomic weight, for beta radiation sources with large activity, light materials such as plexiglass are generally selected for protection first, and then materials with larger atomic weight are selected for shielding. Both internal and external irradiation should be considered in the protection of β - ray.

射線防護(hù)器材之防護(hù)對(duì)象三：γ射線γ射線實(shí)質(zhì)是高能光子束，由于光子不帶電，且其靜止質(zhì)量為0，所以不太容易損失能量。γ射線只有在與物質(zhì)相互作用發(fā)生光電效應(yīng)、康普頓散射、電子對(duì)湮滅三種效應(yīng)時(shí)才會(huì)損耗能量。

Protection object 3: gamma ray gamma ray is essentially a high-energy photon beam. Because the photon is not charged and its static mass is 0, it is not easy to lose energy. Only when the interaction between gamma ray and matter occurs photoelectric effect, Compton scattering and electron pair annihilation, will the energy be lost.

γ射線的穿透能力較強(qiáng)，所以一般會(huì)選擇用原子序數(shù)較高的材料(如鉛、貧鈾、鎢)或厚度較大的混凝土、水等進(jìn)行屏蔽。除此之外，能量越高的γ射線越難防護(hù)。對(duì)γ射線的防護(hù)主要考慮外照射因素，但由于其通常還會(huì)伴隨著α、β衰變的發(fā)生，所以內(nèi)照射防護(hù)也不能忽視。

Because of the strong penetration ability of gamma ray, materials with higher atomic number (such as lead, depleted uranium, tungsten) or concrete and water with large thickness are generally selected for shielding. In addition, the higher the energy, the more difficult it is to protect. The protection of gamma ray mainly considers the external radiation factor, but because it is usually accompanied by α, β decay, so the internal radiation protection can not be ignored.