eV Parts (Prototyping System)

Under construction…

eV Parts

Introduction

Kimball Physics “eV Parts”, a collection of various structural geometries (an “Erector® or Lego® set”- so to speak) of high temperature capable metals and high purity insulators, provide numerous options to either 1) create physical and functional structures or 2) securely mount your apparatus in vacuum environments.

The toolkit enables construction of all types of surface physics and high vacuum apparatus (see the table below).  Mounting structures in Kimball Physics Multi-CF vacuum chambers is especially convenient with the internal mounting “Grabber Grooves” along the internal bore of the CF portals (more detail later in this document).

This toolkit for scientists was born in the physics research lab to initially help graduate students find a more efficient and cost effective path to creating and testing their concepts and prototypes in high vacuum environments.  Many of their applications included charged beam electron and ion beam particle systems (hence came the name eV Parts).

This collection of basic components has now evolved into a toolkit of parts to enable a broad range of capabilities.  They can be used to simply mount a slit or aperture in a vacuum chamber or instrument housing.  Or they can be assembled to create much more elaborate devices such as faraday cups,  phosphor screen detectors or to even fabricate the firing unit of an electron gun system!  A few examples of what can be constructed are listed below:

Table 1:  Prototype Options Using eV Parts

The parts have also been used as components to assist in build devices such as mass spectrometers of several types including quadrupole, RF, and magnetic sector.  In teaching laboratories, the parts have been used in experiments related to basic electron physics, and the construction of simple electron microscopes. They are also well suited for low-energy electron and ion optical applications (such as slits and apertures) and can be adapted to experiments involving large diameter beam intersections, scattering, and cross-section measurements.

eV Part Design

Introduction

The parts are basic structural elements, made of high temperature metal conductors and high purity ceramic insulators, with connectors and clamps to hold everything together.  The parts are non-magnetic and will work well in high and ultra-high vacuum environments with no concerns of volatility (that would disrupt the vacuum). The parts provide numerous versatile solutions and provide convenience and cost benefits in the areas of teaching, research, and manufacturing.

These component parts are made from high quality materials to build rigid, self-supporting, self-aligning and dimensionally stable assemblies that allow accurate alignment of structures such as lenses, slits, apertures, and more.

The parts have standardized dimensions, are manufactured to high tolerances, and are modular and interchangeable. Their assembly into various configurations is intuitive with basic skills and tools-  complex manual skills and equipment are NOT required for their use.

Metal Parts

The conductive stainless steel (304) metal parts, both austenitic and non-magnetic, include a broad range of sizes of precision solid and perforated plates, brackets, rods, cylinders, balls/spheres, These parts are made from refractory materials that are tolerant to heat and wear and nicely endure bakeout operations. As expected, the metals are not volatile and perform well in very high vacuum environments. In addition to stainless steel, other metals are available including Copper (Cu), Molybdenum (Mo) Tantalum (Ta) and Tungsten (W) for available for selected components.

Ceramic Parts

These structures are made from ceramic (high-grade, pure vitreous alumina, Al₂O₃) and provide both structure and excellent electrical insulation / isolation.  The structures include rods and tubing of various lengths and diameters, along with spacers and balls/spheres. The insulating balls are composed of either alumina or sapphire. As expected, the structures are non-magnetic and are not volatile at very high vacuum conditions.

Clamps and Connectors

The connectors and clamping plates are typically metallic and precision fabricated from SS 304. Available connectors include springs, lock rings, machine nuts, screw clamp assemblies, wirenuts, triplenuts, and wound wire. Clamps, often with more elaborate geometries and typically for joining multiple parts, include screw clamp assemblies, clamping plates, and geometric element clamps.

eV Parts are completely compatible with other types of electron gun parts such as those used in the cathode ray tube industry.  Consequently, eV Parts may also be used to modify or add to existing commercial high vacuum apparatus with little effort. It is possible to build structures which are completely non-magnetic.

Mounting Systems

To further expand the functionality of the eV Parts toolkit, a system of mounting channels (aka Grabber Grooves) has been added to the inside bore of most of the larger portals of Kimball Physics Multi-CF vacuum chamber hardware (ports 2.75”and greater). With specifically designed internal mounting clamps (aka Groove Grabbers) that also interface to eV Parts, this allows the eV part fabricated apparatus to be securely mounted and precisely positioned within the vacuum space.  More able this later in the document.

Size Ranges

The parts come in two general size ranges to cover different levels of structure, The size range or series determines the family of overall plate sizes, plate hole diameters and hole spacings.  The parts are available in 2 size ranges B, and C, with a few parts, such as perforated plates, incorporating holes sizes from both families. The table below shows the dimensions of holes, their generalized spacing, and thickness for the various part ranges.  In generalized terms, the dimensions in C series are about twice the dimension in the B series.

Table 2:  Various eV Part Series with Sizes

Getting Started

 Let’s create some basic constructs with the eV Parts Systems to get you familiar with basic construction techniques.  From there, we will then expand more on the diversity and details of the available components and with more advanced applications.

To introduce the system, we will design the following eV Parts 101 basic constructs:

• A grounded metallic aperture mounted inside a Multi-CF chamber in the beam line
• A floating metallic aperture mounted inside a Multi-CF chamber in the beam line
• A phosphor screen mounted in the beam line
• A sample stage mounted in the beam line
• An electron emitter testing fixture

Basic Tools

• Allen/hex wrench
• Forceps or tweezers