BF/DF STEM Detector

Scanning transmission electron microscopy (STEM) imaging can provide structural and compositional information over nanometer and sub-nanometer scales. The Gatan 805 BF/DF STEM detector can be used in bright field (BF) or dark field (DF) modes. Advantages of the detector include ultra-low noise performance, high sensitivity and on-axis installation allowing simultaneous DF imaging and electron energy-loss spectroscopy (EELS).

The detector position (BF, DF or fully retracted) is pneumatically controlled. The detector position is aligned to be the optic axis of GIF or Enfina and is ideal for spectrum imaging and manual EELS experiments.

The electron signal is converted to light using a thick YAG scintillator that operates up to 400kV. The light signal is coupled using a light pipe to a photomultiplier tube (PMT). The PMT and preamplifier are contained in a shield that minimizes the effect of electromagnetic interference. The response of system is linear over standard STEM operating conditions. The bandwidth of the preamplifier can be optimized for pulse counting.

The 805 BF/DF STEM detector is the ideal partner to any GIF or Enfina system.

Specifications

	Detector Type	YAG
	Photomultiplier	Matched to scintillator
	Detector active diameter	BF: 5mm DF: 5-11mm
	Air requirements	300-700kPa (45-100psi)
	Power requirements	100120/220/240 VAC 50/60 Hz 120W
	Acceptance half angles	BF: ß=2.5[mm]/Cleff[mm] < 5.5[mm]/Cleff[mm] DF: ß=2.5[mm]/Cleff[mm] < ß < 5.5[mm]/Cleff[mm]