Click on the links below for useful JavaScript calculators

Wire vibration frequency 

Straw detector critical voltage 

Straw detector wire deflection, due to impact

Straw detector wire deflection, due to initial offset

Straw wire elongation

Specific activity

Minimum detectable flux

Minimum detection time

Cf-252 Activity Calculation for PTI sources 

Neutron Flux Calculator (external website)
(At a minimum, you must specify the geographical latitude and longitude, and the elevation, pressure, or atmospheric depth). The result is the flux relative to that in New York, USA.  Latitude and longitude data can be obtained here.)