Houghton University Digital Archives

The Houghton University Archives serves the students, faculty, staff, administration and alumni of Houghton University by collecting and maintaining a historical record of the University story. The Archives collects, organizes, preserves, and makes accessible materials critical to understanding the historic, present, and future mission of Houghton University and to nurturing identity, purpose, and unity in the University community. This DSpace site provides access to some of the Houghton University's digital collections.


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Now showing 1 - 5 of 8

Recent Submissions

ASA 8-1986, R. Ward Wilson, 1. "Gods Image: The Essence of Human Nature" and 2. "Contextualizing the Gospel, Cross-cultural Values"
(Houghton University, 1986-08) Houghton University EMA Studios
In these two sessions, Wilson discusses various philosophies of the image of God, relating to mankind, the Gospel, and cultural values.
Thin Metal Film Physical Vapor Deposition System
(Houghton University, 2023-05-10) Bowman, Matthew D.
A low-cost, thin film deposition system utilizing physical vapor deposition is being constructed at Houghton University. A mechanical pump and turbomolecular pump lower the chamber to a base pressure of 10−6 Torr. Three graphite crucibles are heated via thermionic emission from three corresponding tungsten filaments. Each filament floats at up to -4 kV with individually controlled currents of up to 3 A. The use of three separate crucibles and filaments allows for the deposition of up to three different materials either simultaneously or sequentially. The 10 cm Si substrate onto which the metals are deposited is mounted on a rotatable feedthrough behind a stepper motor-controlled linear shutter, which provides a method for depositing with a thickness gradient. A Giedd and Perkins evaporation rate monitor allows controlled deposition. The chamber is currently capable of producing films and is being retrofitted to use an Arduino to control the deposition process more easily.
Using Phase Shift Interferometry to Measure the Topography of Thin Metal Films
(2023-05-10) Zdunski, Jonathon
A low-cost phase-shifting laser interferometer is being constructed at Houghton University to measure the thickness and topography of thin metal films produced with a variety of deposition parameters. The modified Twyman-Green Interferometer uses a 632 nm laser. Three piezoelectric ceramic stacks move a reference mirror up to 883 nm along the direction of the beam with a precision of <1 nm. The interference pattern is captured by a 2 MP camera. The system is suspended by springs and uses eddy current damping to decrease the movement of the system. A housing mounted to the outer frame blocks wind produced by the building’s air handling system. A LabVIEW program controls the mirror movement and fits a sine function to the intensity of each pixel vs. reference mirror position. An intensity plot of the fitted phase shifts represents the topography. Initial tests using two λ/10 flat mirrors indicate that the individual pixel height measurements are repeatable within about 1.6 nm. Assuming the film surface is smooth, the maximum repeatability of the overall topography should therefore be <1 nm.
An Ambient Air Scanning Tunneling Microscope to Study the Surfaces of Thin Metal Films
(Houghton University, 2023-05-10) Wilson, Joshua C.
An ambient–air scanning tunneling microscope (STM) is being built at Houghton University to study the crystal growth and transformation of thin metal films. The STM operates by maintaining a constant current between a piezoelectrically–controlled scanning probe and the thin metal film sample while recording the height of the probe relative to the sample stage. This current is produced when electrons from the sample quantum tunnel through the ~10-10 m air gap to the probe, aided by a small bias voltage of ~-1 V applied to the sample. In order to achieve a tunneling gap of this size, the STM uses stepper motors to perform a rough approach of the probe to the sample. The STM is suspended on a dual-stage vibration isolation system which uses springs with eddy current damping to protect the STM from background noise. The STM is controlled by a user interface written in Processing and a Teensy 4.1 microcontroller via Arduino, along with a control circuit. The data collected by the STM are used to create an intensity plot that will act as an atomic resolution “image” of the film surface. All hardware, electronics, and programs have been completely and successfully tested.
Automatic Control of an Inertial Electrostatic Confinement Device
(Houghton University, 2023-05-10) Condie, Micah K.
The Houghton University Farnsworth-Hirsch fusor is an inertial electrostatic confinement device designed for the purpose of studying plasmas, D-D fusion, and as a source of x-rays and neutrons for other experiments. It operates via two concentrically arranged wire spheres with a voltage difference between them of up to 30 kV, ionizing a low-pressure gas to form and confine a plasma. The voltage across the two spheres is measured using a voltage divider circuit allowing an Arduino at the bottom of the chain to measure a lower proportional voltage. The current from the HV grid to the power supply flows through an LED, floating at high voltage, the light from which is then measured at the end of a fiber-optic cable using a phototransistor circuit. The previous fusor remote operating system used LabVIEW and Digi TS4 Port servers to communicate with the high voltage power supply, pressure gauge, and mass-flow controller via ethernet, RS-232, and RS-485. It was redesigned using a python code running on a remote computer to communicate with the instrumentation directly over USB and RS-485. Furthermore, the python code implemented a PID controller so that the pressure in the chamber could be adjusted automatically, maintaining the plasma while raising the voltage. The fusor was tested using air as the ionized gas with limited success using the PID controller. Future experiments will correct the automatic system and test the system with hydrogen then deuterium.