Radiation III: Radiodating

Set up in KPTC 005 or 009 (basement labs) so that you are near the howitzer. There should be 7 individual setups. (The TA setup is no longer needed for this lab.)

• General measuring equipment
  • Rulers
  • Calipers

• Radiation sources
  • Gamma emitters: Cs-137 buttons (7)
  • Indium foils
    • One full container for the “fresh” (not-yet activated) foils
    • One empty container for the “used” (activated, but not yet fully-decayed) foils
  • Lead shielding (3 blocks)

• Demo items
  • Survey meter
  • GM tube with a broken window (so you can see inside)

• Extra equipment
  • GM tube in holder (1 or 2 extras)
  • ST370 Radiation Counter (1 or 2 extras)
  • BNC cable (1 or 2 extras)
  • USB cable (1 or 2 extras)

• Detection equipment
  • GM tube in holder (w/ source holder only)
  • ST370 Radiation Counter
  • BNC cable
  • USB cable

Connect equipment at each station and test with the STX software (with high voltage set to +900 V) using a button source.

In preparation for each session, do the following:

• make sure that at least three ports on the howitzer are available for use (typically P1, P2 and P3 are free and P4 is used by PHYS 211);
• place a class set of indium foils (at least 24 foils, or about 3 per group with a few spares) in one port of the howitzer overnight;
• remove 8 foils (1 per group plus a spare) at some time prior to the start of lab (typically 2-3 hours before the start) and record the “time of death”; and
• place these foils in the lab (in a location available to the TA) and email the TA the “time of death”.

This process allows students to have one dead foil and then take up to two new foils from the howitzer during the lab period if needed as part of their radiodating measurements.