In Conceptual Physics, we study properties of solids. One of the properties for consideration in lab this week was spring constants. We looked at the spring constant of plastic bags by stretching them until the bag broke. We found a standard bag can support up to 12 kg for a short time.
School has just started, the leaves are falling, and so are the rockets. October always brings the rocket lab in General Physics and Principles of Physics - a chance to study projectiles in motion while enjoying a sunny day outside. In the picture at the left, two red spots are just visible in the center of the sky. One is a rocket going up and the other is another rocket coming down. The trick to surviving the lab is to not be under the rocket as it comes down.
Many of our students leave for the summer. A number of them were doing research or internships at companies and labs scattered around the country. One physics major, Darryl, did spend the summer here working on building a ring interferometer. The laser head, some of the mirrors, and the slip-ring assembly are shown in the picture. By the end of summer it was mostly working.
In Physical Electronics lab, we have tried making a transistor as one of the final labs of the quarter. Over the past eight years, several different build processes have been tried but the transistor has never worked. This year was different and with a new boron process, the device shown in the picture works as a pnp transistor. We still need to improve the process a bit so the transistor is a bit more reliable and has a better gain. Now . . . only 499,999,999 more and we will have a single CPU.
One of the advantages of a small physics department is that students can use the lab space and machine shop to work on personal projects. Darryl has built a number of projects during his time at Walla Walla University. This spring has seen the test firing and exhibition firing of his Mark II trebuchet.
For the last part of Nanotechnology Lab, we made a Type-II superconductor. Once it was baked, it was time to break out the liquid nitrogen and test it. Sadly it failed, but we had the ones from previous years to play with. In the picture on the left, a permanent magnet is levitating over the superconductor.
The video here shows the magnetic spinning. Once the liquid nitrogen is out, it is hard to use it only for science. Flowers need to be shattered. Ice cream need to be made, etc.
In the nanotechnology lab we have been looking at several magnetic systems. The most recent lab involved ferrofluids. Ferrofluids are most often used in sealing the area around rotating shafts.
In our lab we just looked at the different shapes we could make while applying external magnetic fields. In the picture at the right, a magnet from a hard drive is held under the glass dish and the spikes are at the approximate ends of the magnet. While a good time was had by all, some of the magnets still are stained.
A short video of the fun is here.
The scanning tunneling microscopes are complete and imaging. They have plenty of room for further improvement, but the basic functionality is there. In the picture below, the scanning tip is shown on the left. The tip is held in the black piece and extends down to the copper sheet that is being scanned. On the right is data from a calibration standard. The field of view is 3000 nm which means the resolution is 300 nm or better for this microscope.
Introduction to Nanotechnology is being taught this winter quarter. In lab we are again building a scanning tunneling microscope. Two years ago when the course was last taught, the best resolution from the student STM was about 1,000 nm. We are trying to best that.
This year we have replaced some of the analog electronics with a higher-powered data acquisition card (NI-6229). Three labs in January got us to finished hardware. In this picture, the electronics are being connected and tested. The next steps are to load in a sample and measure resolution.
A new lab this year was building circuit boards in Experimental Physics I. We used simple equipment and processes so the result is environmentally friendly (we are using a Ferric-Chloride-free process) and inexpensive enough that the students can make circuit boards at home. The total cost of the lab is about $5 per board and does not require anything beyond the parts available at ACE Hardware, Ebay, and Walmart.
B&K Precision Instruments has donated to the physics department seven 2530B digital oscilloscopes. The new scopes replace cheaper scopes and allow much easier transfer of data to the computer. So far, the features on the new scopes have been used heavily in upper division labs and for robotic club testing.
In the picture, the chaotic behavior of a diode circuit is being tested and displayed on the new scope. The xy-scan mode of the new scopes allows for a much better visualization of certain effects.
The big summer project that Calvin worked on was building the Zeeman Effect apparatus for Dr. Liebrand. This project has been tried during past summers but has never showed the right result. This summer was different and with a little help from Darryl in depositing the right amount of aluminum on some optical parts, Calvin built and aligned the system. One week before school was to start, the splitting effect was documented. Good job, Calvin.
The completed Zeeman apparatus will be used in the Modern Optics Lab which Dr. Liebrand teaches every two years.
This summer, two physics majors - Darryl and Calvin - worked on several projects in the Physics Department. One of the biggest projects was to create a machine shop. Space was cleared in a storeroom and a large counter was installed. The existing band saw and end mill were mounted on the counter top. A lathe and table vice were purchased to add to the collection. Every week more tools and supplies are purchased. A drill press is the next big piece of equipment to install.
The machine shop is already in heavy use. Much of the summer work that Darryl and Calvin did included making parts on the existing equipment or waiting for the next tool to arrive. Since space in the shop is limited, the end mill and lathe are of hobby size. Parts larger than 6 inches need to be fabricated on tools found in the engineering shop.
It is finals time and students are studying hard and taking hard tests. Dr. Ekkens allows a sheet of equations for his tests. However, it is critical to get the right equations for the subject material. While Maxwell's Equations are amazing and accent any wardrobe choices with a touch of class, they are of limited help on a test covering semiconductors.
The Astronomy Class usually takes a trip to the gravitational wave detector (LIGO) at Hanford. This year the physics majors and some honors students joined the trip. The system is being updated to Advanced LIGO so we were able to see some of the new hardware ready for installation.
Three senior physics majors are taking a directed study course this quarter covering chaos. Each week, the class reads a chapter in a history of chaos book. Then during class, each person works on a computer program or other project to model the chaotic system that was covered in the reading. In the picture, the design on the left was created using three rules, a random number generator, and about 30 minutes of programming time. The fern on the right uses six rules and was not assigned for class.
Roy Campbell spent the Autumn quarter of 2010 on sabbatical doing research in biophysics. In early December, he presented a physics seminar for faculty and interested students and will be giving a paper at the March APS meeting in Dallas entitled Maximum Caliber Analysis of Ion-Channel Gating.
This summer, two physics majors - both named Jeff - worked on several projects in the Physics Department. The large projects were a design for the circuit board for the student STM, calibration of a resonant crystal to determine metal deposition thickness, and an improved build process for pn junctions. The resulting pn junction is shown in the picture.
This summer, the Physics Department is offering two quarters of Astronomy. The flexible course times allow observation events that don't fit well into the normal school year. Several transfer physics majors also worked on making up a lab course. The lab course covered programming, mechanical design considerations, and electronics. The final project of the course integrated all these elements into a robot armed with a low-power laser that shoots at anyone making noise.
All connections have been made. The inspections are complete. The monitoring hardware and software is in place. The system is switched on at 5:00 pm on March 9, 2010. Now we collect photons and data.
All six panels are mounted to the roof. The inverters are in place and wired to the new gray box on the side of the observatory. The panels are not connected to the inverters yet.
In Experimental Lab II, we are looking at a variety of experiments. The second lab of the quarter dealt with vacuum systems. We created a plasma at 100 mTorr and watched how it behaved as we turned up the voltage. This arc seems to happen only when we use an older power supply.
Dec. 16, Update. Solar panels are being mounted to the roof of Kretschmar Hall near the observatory. The first three panels are up. The next three are waiting for some mounts to be completed. No wiring is in place yet.
A scanning electron microscope (SEM) was donated to the Physics Department at the end of the summer. With this addition, the Physics department now has the complete suite of microscopes necessary for nanotechnology work (SEM, AFM, and STM). The SEM has been used in several labs already this year. The inset image at the upper left is of a penny. The stamp date of 1989 is magnified 150 times so we can see the first 9. The right inset image is of one edge of the 9 magnified 5000 times.
Four physics majors worked on projects for the Physics Department during the summer. Jeremy and Jeff stand next to a demonstration built to test a Classical Mechanics Problem.
Page maintained by Tom Ekkens
Last update on May 16, 2013