DyMaxion Enclosed Ion Source Gas Analyzer

Increased sensitivity and decreased background noise are possible due to the ionizer design


Increased sensitivity and decreased background noise are possible due to the ionizer design. An enclosed ion source operates with sample pressures as high as 10-3 torr with no need for futher pressure reduction of this differentially pumped inlet system. Higher sample pressures contain greater numbers of neutrals and more sample to ionize. With each order of magnitude increase in pressure, signal strength varies proportionally with sample density. This is accomplished by confining the sample within a (relatively) small ionization volume. The sample is constrained within the ion volume that that has a two small slits on either side of the ion volume. Bombarding electrons enter through these slits, ionizing the sample. Ions formed near the small exit hole of the ion volume are immediately extracted into the mass filter, and have little opportunity to react with neutrals. Ionization efficiency is high, since virtually the entire sample passes through the small ionization zone. The main transport mechanism from the source to the downstream mass filter is a pressure gradient, resulting from the higher pressure in the ionizer versus the lower pressure in the downstream mass filter. Hence, the source is conductance limited by the pressure difference.


Mass Range 1-100, 1-200, 1-300 AMU
Operating Pressure Range 10-4 Torr to ultrahigh vacuum
Minimum Detectable Partial Pressure 5 x 10-12 Torr ( 5 x 10-14 Torr for electron multiplier units )
Resolution Adjustable to constant peak width (0.5 AMU at 10% height)
Emission Current 0.1 to 10 mA; 50 mA to degas
Electron Energy 30 to 150 volts to operate; 200 volts to degas
Ion Energy 1 to 10 volts
Source Sensitivity (Faraday Cup) 2 x 10-4 Amps per Torr at detector (measured with nitrogen at mass 28) with peak width = 0.5 at 10% height and 1 x 10-3 Amps emission current
Power Requirements 24 VDC @ 3 Amps; 110/220 VAC, 50/60 Hz adaptor available
Mass Stability ± 0.1 AMU after 30 minute warm-up
Peak Height ± 2% after 30 minute warm-up
Minimum PC Requirements Windows 98 through Windows 8
RS-232 Serial Communications
Isolated; baud rate selection of 1200 to 38,400; 9-pin, female D-connectors
RS-485 Addressable Communications Interface Isolated, baud rate selection of 1200 to 38,400; programmable addresses; 2-pin, female D-connectors
Optional Analog/Digital I/O Board Includes two analog inputs, two analog outputs, six relay contact closures, and four digital inputs
Physical Dimensions
Weight 4.6 lb (2.1 kg) without head
74. lb (3.4 kg) with head
Width 4.5 in. (11.4 cm)
Length 9.0 in. (22.9 cm)
Height 5.25 in. (13.3 cm)


Dycor Mass Spectrometer Gas Analyzers Productsheet
Dymaxion Mass Spectrometer Productsheet