RADIOACTIVITY

Rubi AlcazarRegine BaileyJose MartinezBruno - LeaderDanielle - Leader

INTRODUCTION

Electromagnetic radiation: energy in the form of electromagnetic waves These waves include microwaves, x-rays and visible

light Radioactivity: the emission of energetic particles

or high frequency electromagnetic radiation by elements with an unstable nuclei

Unstable nuclei: when the atom gets too big to be stable because there aren’t enough neutrons to hold it together

DIFFERENT TYPES OF RADIATION

Alpha: particle; pretty slow (relatively speaking), can be stopped by paper, skin or clothing

Beta: particle; relatively light (1/2000 mass of 1 electron); can be stopped by aluminum foil

Gamma: electromagnetic; has a high energy because of its frequency, can only be stopped by lead

HOW RADIATION AFFECTS ATOMS

There are two ways these particles can affect atoms.

electron recoil an incoming particle knocks out an

electron from an atom nuclear recoil

an incoming particle interacts with the nucleus.

OBJECTIVE & PROCEDURE

Our objective for this project was to calibrate the detectors by using a radioactive source

A radioactive source was taken and was put next to the detector

Lead bricks were placed around the fridge to block out background radiation

Afterward, since the cadmium was already on the detector, we put the barium outside

Overnight, the detector recorded many events, when a particle causes vibrations in the detector,

We measured the amplitude of the charge pulse the hits produced

LAB ACTIVITY PICTURES

The lab procedure

BARIUM•Radiation given off by a Barium source. •Barium gives off Beta and Gamma rays when decaying•The group looked at the graph and estimated which energy matched which peak•This helped the group determine a range for the graph•The group calibrated the graph to find the real number, and the right energy in which there were the most event per particle.• The group found that their guesses for the percent where every close. The three highest point were close to: 18%, 62% and 9%, which is: 303keV, 356keV and 383keV, respectively

CADMIUM

•This graph is the radiation given off by a Cadmium source•Cadmium also gives off betas and gammas, but we were mainly looking at the gammas•Just like the Barium source, the group also calibrated this graph using the same methods•The two peaks were 0.025 (18%) and 0.022 (84%). This translates to 25 keVand 22 keV, respectively.

CADMIUM & SUMMARY•This is a graph of the data with barium and californium• There were a lot of

gammas and neutrons•We plotted the charge produced by the incoming particle against the vibrations produced

IN GENERAL: •Basically what we did was make a histogram of the number of evets versus the amplitude of when they had happened•We found the peaks on the plots and the amplitudes of when they occurred and what the energy was at that point