22.S902 | January IAP 2015 | Undergraduate
Do-It-Yourself (DIY) Geiger Counters


Course Meeting Times

Lecture/lab sessions: 5 sessions / week, 4 hours / session.

This course lasts for one week, meeting on five consecutive days. The first three sessions are a mix of lecture and lab time, while the final two sessions are just lab time.


Welcome to the first DIY Geiger counter class! You are embarking on an educational experiment, designed to provide a hands-on, interactive introduction to Nuclear Science and Engineering (NSE) at MIT. Rather than bore you with lectures, we believe that direct, physical engagement is the best way to jump right into a new and unfamiliar subject. Everything that we present on the board, you will be exploring and proving using your own hand-built Geiger counters. You will explore different types and sources of radiation, how to detect them, how to shield them, how to accurately count / measure their activity, and explore cryptographical applications of radiation. This course is meant to be enjoyable and rigorous at the same time.

Course Objectives

We hope you will learn and put to use a diverse set of skills, both theoretical and practical, by the end of this course. While we will cover many topics during this course, most will be at an intuitive, freshman-accessible level for the sake of time and ease of learning. Specific objectives of this course include:

  1. Learning Objectives
    1. Types of radiation
      1. Alpha (α) particles: Charged, heavy helium nuclei
      2. Beta (β) particles: Electrons originating from the nucleus
      3. Gamma (γ) rays: High energy photons
      4. Neutrons (n): Uncharged nucleons
      5. Others (neutrinos, anti-particles…)
    2. Sources of radiation
      1. Natural sources: Cosmic rays, terrestrial isotopes
      2. Man-made sources: Medical procedures, consumer products, nuclear power, fallout
    3. Nuclear reaction energetics
      1. Predicting type and energy of radiation
    4. Principles of radiation shielding
      1. Time & distance
      2. Shielding, logarithmic attenuation
      3. Energy deposition, exposure rates
    5. Detector theory and limitations, specifically Geiger counters
      1. Principles of operation
      2. Dead time
    6. Statistics, uncertainty, and error analysis
      1. Calculating uncertainty
      2. Propagating errors
      3. Determining how long to count
    7. Real-life implementation
      1. Circuit theory
      2. Additional sources of error and dead time
  2. Laboratory Objectives
    1. Learn how to solder and assemble circuits
    2. Develop testing and debugging skills
    3. Understand sources of experimental error
    4. Plan experimental procedures for faster success


Students should expect 2 to 4 hours of homework per night.

The course grade is based on laboratory reports, problem sets, and a completed working Geiger counter. There are no exams.

Homework Assignments

Since this course is only one week long, we had to get creative with homework assignments. Therefore, we have constructed the following rules for this course:

  1. All assignments are due two class days after they are assigned, to give you time to ask questions.
  2. Homework assignments may look short, but they will require you to research things and think creatively.
  3. Always cite your sources of information! This includes journal articles, books, databases, and websites. We will use this formatting guide for references:
  4. You may prepare your answers however you like, but they must be submitted electronically.
  5. You may work together in any sized group. If you do, you must clearly write with whom you worked.

There are two types of homework assignments: Problem Sets and a Lab Report.

  • For problem sets, just answer the questions to the best of your ability. Be quantitative, use numerical justification whenever possible. For example, if we ask you why one shouldn’t ingest things that emit alpha particles, just saying “alphas are bad for you” or “they release lots of radiation, which is dangerous” is not sufficient. Instead, give an answer like: “Alpha particles have very short ranges, but they do Tons of damage to tissues due to their high mass and charge. Therefore, while one’s skin would normally shield against alpha particles, ingesting alpha-emitters puts the alpha particles right next to the cells which they can damage.”
  • For lab reports, also just answer the questions completely and thoroughly. We recommend using your answers from the problem sets, as well as information from the lecture slides and primary sources (journal articles, NIST databases) to complete the lab reports.


Problem sets (all together) 25%
Lab report 25%
Successfully building the Geiger counter 50%

Tips for Success

This course may look jam-packed with things to learn and assignments to do, but it really isn’t. All the assignments are designed to:

  1. Drill you in the mathematical and intuitive techniques taught during class;
  2. Get you thinking more deeply about using your new knowledge to solve open-ended problems;
  3. Get you to pre-compile information for the lab reports.

Therefore, if you do the readings, the assignments should be relatively easy. If you do well on the assignments, the lab reports should be very easy!


1 Radiation decay chains, half-life (42 pages) Radiation basics; radiation energetics (2 hours)

Geiger counter circuits (1 hour)

Start building! (1 hour) Write analysis script
2 GC theory, dead time (16 pages) Geiger tube theory, dead time (1 hour) Build GC (3 hours)  
3 Shielding, range, dose (15 pages) Shielding and range; radiation protection (1 hour) Build GC (3 hours) Pset 1 due
4 Error, uncertainty (21 pages) No lecture Dose, shielding, background (4 hours) Pset 2 due
5 No reading No lecture

Finish Geiger counter lab (4 hours)

As time allows, build a random number generator for cryptography

Pset 3 due

Lab report due 3 days later

Course Info
As Taught In
January IAP 2015
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