| Q. | What is CdTe? |
| A. | CdTe is a compound semiconductor made from Cadmium and Tellurium. CdTe, as next generation detector, has attracted market interest since it absorbs radiation and convert it to electronic signal efficiently. |
| Q. | What makes difference between CdTe and the other radiation detectors? |
| A. | Lithium Drift Silicon or Germanium is the typical semiconductor-based radiation detectors. The use of these materials is, however, limited to special physical and chemical applications, as these detectors need to be cooled down to -196 degree C with liquid nitrogen all the time. |
| Q. | What is the characteristic of Cdte detector? |
| A. | In the medical field, Image Intensifier (I.I.) or a combination of Scintillator and Photo-multiplier (PMT) are mostly used. Miniaturization of the device is hard to achieve from this method, because it requires converting radiation into light first and then amplifying them in vacuum tubes. On the contrary CdTe detector solved these problems and realized low-dose clinical treatment, shortening operation time, miniaturization, lightweight and better spatial resolution. |
| Q. | What is "Semiconductor detector"? |
| A. | The radiation detector, which make use of phenomenon that semiconductor generate electrons when radiation coming into. One of characters of CdTe is high energy resolution and it's used popularly in spectrum measurement or dose measurement. Si or Ge are also used in this field CdTe contributes low dose and miniaturization of devices due to its characteristics such as high absorption or room temperature operation. |
| Q. | What is "Scintilator"? |
| A. | The material emits lights at irradiation or the detector make use of this emitted light to measure radiation. NaI, CsI, BGO are popularly used in this field, hoowever they need PMT or photo diode. |
| Q. | What is the reason CdTe has high absorption? |
| A. | CdTe is a compound semiconductor made from two materials as Cadmium and Tellurium. Since atomic number of both material are high (Cd:52, Te:48) and CdTe has high density (5.85g/cm3), it can absorb radiation effectively. |
| Q. | What is the difference between direct conversion and in direct conversion? |
| A. | Electric signal is made from radiation directly in direct conversion. The other hands, electric signal is converted only after coverting to light from in coming radiation in indirect conversion. Measuring the lights by photo diode it can measure the radiation energy or dose. Due to double conversion, effectiveness can be lost during the process. With imager, spatial resolution can be reduced by the scattering at the light conversion in indirect conversion. |
