Cathodoluminescence assisted spectroscopy system

In the early 1960s, with the development of electron probes, characteristic X-ray radiation was used to analyze mineral specimens. One ancillary product of this work is cathodoluminescence observation, which quickly became a very important independent research field, leading to the development of electron beam sources towards simpler and microscopic methods, using cold cathode tubes as the electron beam source.
The cathodoluminescence analyzer based on cold cathode is the foundation of energy spectrum analysis system, just like RELION Ⅲ CL, this type of electron gun is used in the additional device (CMA) of cathodoluminescence microscope, which is based on the principle of cold cathode discharge. Compared with electron microprobe (EMP) and scanning electron microscope (SEM), it is the most widely used and simple. It also provides a neutral environment, so there is no need to use samples with conductive coatings for sample preparation. During the process of electron bombardment generating cathodoluminescence, X-rays are produced. The use of X-ray detectors in additional devices of cathodoluminescence microscopes, combined with cathodoluminescence and transparency observations, provides a universal function of rapid elemental analysis.

The cathodoluminescence instrument uses an electron gun with a cold cathode, which generates an electron beam under the discharge of the cold cathode. The working pressure of the system is generally between 40 and 100 milliTorr. When the beam current reaches 1mA, an electron beam of 1 to 25Kv will be generated inside the electron gun. The scattered focused beam spot on the sample is approximately 10mm, and point focusing can be reduced to a diameter of 1mm or smaller
When the air pressure reaches 40 to 100 milliTorr, the vacuum system can reach a stable value, and the adjustment of cathodoluminescence focusing is relatively simple, indicating that cathodoluminescence can already be observed. This device saves high costs, high vacuum systems, and corresponding maintenance costs, while reducing many inconveniences. The vacuum chamber can automatically or manually remove gas between samples, and even if the samples are changed multiple times, the vacuum chamber can still reach working condition in 2 minutes or less.
The main technical parameters of cathodoluminescence analyzer and energy spectrum system are as follows:
Vacuum degree: The maximum limit is 0.25 Pa, providing maximum protection for the sample.
Electron gun: The electron gun is a horizontal cold cathode electron beam type, with a maximum voltage of 30 KV, typically used for adjustment between 5 KV and 25 KV.
Cathode voltage: 0-30KV, overvoltage protection.
Best current: 0.15-1mA, continuously measurable, overcurrent protection. The maximum beam current can reach 5mA.
Focusing: It has the function of adjusting the scattered focus to the point focus, and the electron beam spot can be adjusted according to the applicable requirements of the sample.
Detector type: Silicon Drift Detector (SDD), size 7mm2, 10mm2, silicon thickness 500 μ m; (Optional)
Energy resolution: minimum 145 eV;
Signal to Noise Ratio: 8200:1
Be window thickness: 12.5um, 25 μ m (optional)
Has the following main characteristics:
1: Affordable prices.
2: High speed operation.
3: Easy and simple operation and maintenance.
4: The sampling preparation work is simple and convenient.
5: Ability to maintain good optical microscope capabilities.
6: Microscopic photography processing for sampling can be easily achieved.
7: Having ordinary transmitted light (TRL), Polarized light (POL), The joint observation capability of cathodoluminescence (CL) and EDS.