Linefit was written by Cal Poly Computer Science students Joel Onofrio and Kiet Tran. Enter the "x" and "y" values for your data, and the program will plot the data, find the slope and intercepts. The program will also find the uncertainties in these values. You can also change which data is used in the "linear regression fit". Netscape 4.08 or better or IE 4.0 or better is need with this applet.

photon interference was written by Cal Poly students Matt Henderson, Chang Kim and Jason Kang. Just choose the number of windows (or screens) and use the task bars.

photon interference applet was written by Cal Poly students Brian De Wolf, Vern Jensen and Juan Pastor.

oscope was written by Cal Poly students Michael Lee, Benjlyn Lopez and Pascal Huoth. This version has "sliders" along the axis to allow the user to move the signal around. Click "randomize" a few times to get a nice signal. Note, the nice help box.

Oscilloscope was written by Cal Poly students Erik Waibel, James Wong, Devin Smith and Phan Su. This applet doesn't have sliders, but it works very well, and is a good version to start with. There is also a help box.

oscilloscope was written by Cal Poly students Wei Zhao, Mark Soriano and Mihn Truong. This version was the first to use "sliders" to move the signal around. It is well written and simple to use.

alkali2 was written by the student group led by Anh Mach. It can run with Netscape 3.0 or better.

alkali1 was written by the student group led ty Xiong (Sean) Lin. It can run with Netscape 4.5 or better.

How to use the Alkali Energy Level Programs

The program calculates the energy levels for the valence electron for the alkali elements. Pick an element from the box. Pick a value of the parameter c (Angstroms). Then click on calculate, and wait for the calculation to finish. First the experimental values of the energy levels (in eV) for the l=0, l=1, and l=2 levels are printed, Then the calculated values are computed and printed. Vary the parameter c (Angstroms) for the best fit to the experimental values.

The program calculated the energy levels as follows: It is assumed that the valence electron experiences a "mean field" potential, V(r), due to the nucleus and the other electrons. The potential V(r) is inserted into the Schroedinger equation, and the code solves Schroedinger's equation for the bound states. The potential V(r) is taken to be the sum of a potential due to a point charge (the nucleus) of magnitude +Ze and a screening potential due to the other (Z-1) electrons in the atom. The screening potential is that due to a uniformly charged sphere of radius c and total charge of -(Z-1)e.

Click here for the detector with data for K40 half-life determination. The data are: One minute counting time for 0.84 micro-Curies (0.84uCi) of Cs137; One minute counting time for 0.35 micro-Curies (0.35uCi) of Mn54; One minute counting time for 0.75 micro-Curies (0.75uCi) of Na22; One hour counting time for 30.2 grams of KCl; and a four hour background count. All samples have approximately the same source detector geometry. Your goal is to determine the half-life of K40 from this data. One approach you can take is to first find the efficiency of the detector at energies 662KeV, 835KeV, 511KeV, and 1275KeV using the three standards. Then extrapolate your results to estimate the efficiency of the detector at 1460 KeV, which is the energy of the gamma emitted by K40. Using the counts from the KCl sample, you can determine the half-life of K40. Remember to subtract the background K40, to include the yield factors, and the natural abundance factor of K40 (0.0117%).

Click here for the Detector for lead absorbers. If you want information about the data the detector displays, go to absorber information.

Click here for the Detector for aluminum absorbers. If you want information about the data the detector displays, go to absorber information.

Click here for the Germanium Detector. If you want information about the data, click on data info . Here are lists of the energies for the U235 decay series , U238 decay series , Th232 decay series .

Click here for the Geiger Counter . The Geiger counter has two sample holders. In each sample holder you can pick either an empty holder, Ba137m, or Mn54(5 micro-curies). The detector has a dead time, and there is a background. To record counts from the Ba137m samples, you need to click on "squeeze out Ba". The button refreshes both sources when clicked. The sources are only "counted" when they are in the sample holders. Some experiments that can be done are: 1. Test if the statistics of the detector follow a Poisson distribution (Statistics of Nuclear Decay) 2. Measurement of the detector's dead time 3. Measurement of the efficiency of the detector 4. Measurement of the half-life of Ba137m (remember to account for deadtime and background).

riacal , riasamp transport assay