COLUTRON ION BEAM KITS AND COMPONENTS

{Ion sources, lens systems, velocity filters (Wien filters), ion beam decelerators}

Circuit Diagrams for Colutron Ion Beam Kits (BK-series) and Ion Guns (G-series)

Ion Source Assembly Model 100 and Model 100-Q

Colutron Model 103 Heat Sink

Colutron Model 200-B Lens System

Colutron Model 300, 600 and 600-B Velocity Filters

Colutron H-Series Velocity Filters

Colutron Model 400 Decelerator

The Colutron Ion Beam Kit consists of an ion source, heat sink, acceleration and focusing system, vertical deflection plates, velocity filter, and velocity filter guard ring control unit (not shown). A beam decelerator is also available separately. The beam kit can be operated from 1 eV to 10 keV with ion currents up to several microamperes. The velocity filter analyzer can supply mass separated beams with a resolution of up to M/D M ~ 400, where D M = full width at half peak height. The dispersion of mass separated beams is adjustable (Velocity Filter Specifications). The energy spread of the ion beams produced by the Colutron ion source have been measured to be as low as 0.11 eV. This is mainly due to the dense plasma conditions within the ion source. The overall length of the kit when assembled is approximately 16 inches without the decelerator. Any component of the beam kit may be purchased separately. The components are also available mounted inside vacuum housings (see Colutron Ion Gun Systems ). The table below shows components available with the BK-series kits.
 

Kit

Ion Source

Heat Sink

Lens System

Velocity Filter

Model BK-3

Model 100-Q

Model 103-B

Model 200-B

Model 300

Model BK-6

Model 100-Q

Model 103-B

Model 200-B

Model 600

Model BK-6-B

Model 100-Q

Model 103-B

Model 200-B

Model 600-B

 

CIRCUIT DIAGRAMS

Ion Source Assembly Model 100 and Model 100-Q

The Colutron Ion Source is a convenient plug-in unit that eliminates handling and assembling of a number of small parts, as with conventional ion sources. This feature makes for very swift and easy installation and removal. Current outputs are easily controlled up to the milliampere range. The energy spread of ion beams extracted from our source has been measured to be as low as 0.11 eV. A magnetic field is not needed for our source to function. Extraction and ionization efficiencies for most elements range from a few percent to 30 percent. The Colutron Ion Source is available in a Boron Nitride (Model 100) and Quartz (Model 100-Q) construction. The Model 100-Q is shown above. The Model 100-Q has the added advantage of a lower outgas rate than the Model 100 when the source is initially turned on, and hence saves time during the initial start up of the source. A complete Colutron Ion Source Assembly (Models 100 or 100-Q) is composed of the following parts: ion source Model 101 or Model 101-Q with gas inlet tube, ion source receptacle, gas tee and charge holder. We also have a third plug-in ion source Model 101-O that incorporates an oven capable of evaporating material up to 2,000 C. The oven source is available with the Boron Nitride construction only. All receptacles are furnished with five electrical feedthrough connections to accept either the Model 101 and Model 101-Q plug-in sources without oven, or the Model 101-O plug-in source with oven. When the source with oven is not used, the extra two feedthroughs could be used for thermocouple wires etc. The Colutron ion source can be used for either solids or gasses. When solid charges are preferred, a charge holder is necessary. Charge holders made of stainless steel, quartz, and alumina. The alumina and quartz charge holders can also be used with the carbon tetrachloride (CCl4) method. This method is used for internal chlorination of a charge material. Some materials such as rare earth metals become more volatile and more easily ionized within the ion source when chlorinated with CCl4. For exploded views and part numbers of the Colutron Model 100 and 100-Q ion source, see Exploded view of Colutron Ion Sources.

POWER REQUIREMENTS:

IMPORTANT: Ion source voltages must be voltage regulated.

COOLING REQUIREMENTS:

The ion source requires the liquid cooled heat sink model 103. A cooling rate of 0.5 liters/min is required.

COLUTRON HEATSINK MODEL 103

 

The Colutron Heat Sink is made of 304 stainless steel and is bakeable. It is a liquid cooled unit, with the cooling jacket completely surrounding the ion source. The inlet and outlet holes are 1/8 N.P.T. The Model 103 is available with a Conflat (model 103-B) or O-ring (model 103) sealing surface. Colutron recommends the model CU-1 cooling unit for ion source cooling, especially when used together with the model 600-B velocity filter or G-2 ion gun system. The cooling unit uses DupontÒ HFC-134a refrigerant. The Heat Sink weighs about 6 1/2 lbs.

COLUTRON LENS SYSTEM MODEL 200-B


The Lens System Model 200-B is designed for operation with the Colutron Ion Source Models 100 and 100-Q. The Lens System can extract and focus beams over an energy range from 1eV to 10 keV. It consists of an extraction lens in combination with an einzel lens. The Lens System can easily be attached to any of the Colutron Velocity Filters Models 300, 600, and 600-B. The Lens system also comes equipped with a set of vertical deflection plates mounted at the beam exit. For beam energies less than 500 eV, the Colutron decelerator Model 400 is recommended.

 

COLUTRON VELOCITY FILTERS

 

MODEL 600-B                                                            MODEL 300

The Colutron velocity filter is an E x B type "Wien filter", and consists of a magnet and a pair of electrostatic deflection plates. The inherent focal property of the standard Wien filter has been overcome by the Colutron filter by properly biased guard ring electrodes. These electrodes guard the electric field from the magnet pole pieces, and also allow the electric field to be shaped for focussing and non-focussing configurations. The electric field plates are mounted between the magnet poles to produce an electric field E perpendicular to the magnetic field B (crossed E and B fields). The Model 300 (shown in diagram below) is 4.4" long and 3.5" wide. The Model 600 and 600-B are similar except that the overall length is 9.10"and width is 4.40". In most cases, the velocity v = (2qV/m)1/2 of charged beams are obtained by accelerating the particles of mass m, and charge q across a constant electric potential V. Different masses in the beam will be dispersed by the filter since they have different velocities. The filter's ability to disperse masses makes it a superior tool in mass spectroscopy, and some of its main features are:

Straight line system

Adjustable dispersion

Small size; up to 50 times smaller in weight and size compared to a sector magnet analyzer.

The filter will also select the same velocity for both negative and positive particles simultaneously.

The Colutron filter is normally operated as a non-focusing device. However, by a slight adjustment of one or two guard ring potentiometers (balance or middle shim of the Model GR-3-6 control unit) the filter becomes a cylindrical lens. This feature is often used when a line image at the target is required. The capability of the filter is determined by the following formulas:

D ~ [laE (D M)]/[4VM], where

D = the dispersion between the masses M and (M - D M), and undeflected and
M=2qV[B/E]2 where M = the mass (mass number) which is passing through the filter collected on the target.
a = the length of the filter
l = the drift distance from the center of the filter to target (drift distance).
E = the electric field strength in V/m.
V = acceleration voltage or ion energy.
B = magnetic field strength.
q = the ionic charge.
M/D M = maximum mass resolution; D M= the full width at half maximum intensity.
(Example of the velocity filter dispersion calculation and filter operation).

The model 300 and 600 velocity filters are non-bakeable and can be used in vacuum systems with pressures as low as 1 x 10-7 Torr. The Model 600-B velocity filter is bakeable up to 200 C and can be used in vacuum systems with pressures as low as 1 x 10-10 Torr. In order to make the velocity filter bakeable, the magnet coils of the velocity filter are encapsulated in stainless steel jackets. This also allows the Model 600-B magnet coils to be liquid cooled and capable of higher magnetic currents and magnetic fields (see specifications below).

OPTIONAL EQUIPMENT

All the Colutron velocity filters are available mounted in vacuum housings (Colutron H-Series Velocity Filters ).

Model GR-3-6 Guard Ring Control Unit (Supplied with Colutron Ion Beam Kits and Gun Systems).

Model CU-1, HFC-134a cooling system (Cooling required for Model 600-B velocity filter).

Model BVS-1 and BVS-2 Beam Viewing Systems. Velocity filter resolution can be vastly improved by optimising beam profile using the new Colutron BVS systems (see S.G. Hall et al., Rev. Sci. Instrum., 68, 3335 (1997)).

 

 

This picture was made with the Colutron model G-2 ion gun with model 600-B velocity filter, BVS-1 beam viewing system with optional CCD camera (BVS-1-OPT02) and image processing system (IPS-1). The picture above shows the spatial profile of 4 keV, H3+ (at top), H2+ (middle) and H+ ion beams. The velocity filter dispersion was set low to get all three ion beams onto the viewing area of the BVS-1. Below, is a SIMION 3D ion beam trajectory simulation of the above example.

SIMION 3D ION TRAJECTORY SIMULATION
 

POWER REQUIREMENTS

 

Model 300

Model 600

Model 600-B

Electric Field (Horizontal deflection plates)

350V, 120 mA

350V, 120 mA

350V, 120 mA

Magnet

9.5V, 3A

9.5V, 3A

28V, 14A

 

VELOCITY FILTER SPECIFICATIONS

 

Model 300

Model 600

Model 600-B

Length (a)

0.076m (3")

0.152m (6")

0.152m (6")

Max Electric Field (E)

12,500 V/m at 225V

16,800 V/m at 300V

16,800V/m at 300V

Acceleration Voltage (V)

10eV to 10keV

10eV to 10keV

10eV to 10keV

Max. Magnetic Field (B)

1,100 Gauss

1,100 Gauss

3,000 Gauss

Resolution (M/D M)

@ 200

@ 400

@ 400

Beam Aperture

1.91cm x 1.91cm

1.78cm x 1.78cm

1.78cm x 1.68 cm

Max. Magnet Power

30 Watts

30 Watts

400 Watts

Weight (lbs./kg)

12/5.5

21/9.5

20/9

Vacuum Range-Torr

10-7

10-7

10-9

Max. Bakeout Temp. (C)

-

-

250

 

NOTE:
Model 600-B has magnet coils encapsulated in a stainless steel jacket for liquid cooling. Please use only an ozone safe refrigerant such as Dupont HFC-134a or Kerosene for cooling. Colutron recommends the model CU-1 cooling unit which uses the HFC-134a refrigerant. DO NOT USE WATER. Cooling rate is 0.5 liters/min.

SAMPLE MASS SPECTRUM

COLUTRON H-SERIES VELOCITY FILTERS

Colutron also offers velocity filters mounted in vacuum housings (300-H, 600-H and 600-B-H). Model 600-H is shown above. The model 600-B-H, which is the same size 600-H, has cooling connections for the magnet coils that are not shown in the diagram. The overall length of model 300-H is 6.750" instead of 10.25" as shown in the picture, and the side feed-through ports are centered between the two standard rotatable 8" Conflats, with a 6" ID. If a custom housing is needed, please send a drawing for quotation.

COLUTRON DECELERATOR MODEL 400

 

The Model 400 Decelerator is of the Menzinger type. It consists of 5 focusing elements that are mounted inside a vacuum tube with two 2 3/4" Conflat flanges. O-ring groove or smooth face flanges are also available for an additional charge. The focusing elements without the vacuum housing is also available separately (Model 400-L). The Model 400 is designed for ultra-high vacuum and is bakeable to 250 C.

The Decelerator is designed for an energy range from about 1eV to 1 keV. Beams can be decelerated to 1/200 of their original energy without appreciable beam current loss (see figure below for Decelerator performance). The Model 400 weighs about 2 1/2 pounds.

 

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