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"Background radiation" nghĩa là gì?
19 Apr, 2023
"Background radiation" = phông phóng xạ -> nghĩa là phóng xạ tự nhiên của trái đất thường thấy trong một số loại đất, đá.
Ví dụ
In parts of Kerala, background radiation levels, or that emitted (phát ra) from natural sources such as rocks, sand, or mountains, are nearly three times more than what’s been assumed, a pan-India study by scientists at the Bhabha Atomic Research Centre (BARC) has found. This doesn’t however translate to an elevated (tăng cao) health risk.
The COBE/FIRAS detected the first thermal spectrum (quang phổ) and observed that the obtained experimental results are similar to the spectrum of a blackbody at T = 2.728 K. After the detection (phát hiện), much research has been conducted on cosmic microwave background radiation.
Remarkably, the amount of dark matter, which we can derive from our measurements (số đo) of the minute temperature fluctuations in the cosmic microwave background radiation, agrees with the value deduced from observations of the motions of stars and galaxies. However, the value we derive from the CMB measurements is much more precise (chính xác).
People are also exposed to natural radiation from cosmic rays, particularly at high altitude. On average, 80% of the annual dose of background radiation that a person receives is due to naturally occurring terrestrial (mặt đất) and cosmic radiation sources. Background radiation levels vary geographically due to geological (địa chất) differences. Exposure in certain areas can be more than 200 times higher than the global average.
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