A disc burner and its control method applicable to high speed disc burner, to solve disc burning failure problem due to burning speed exceeding encoding speed. The invention also includes a method to detect a mutant strain of Flaviviridae and a method for its treatment. A detector assembly senses the X-rays scattered from the sample as a function of angle while the radiation source is in either of the first and second source configurations and in either of the first and second source positions.