# Doppler coefficient

1. Oct 15, 2004

### eulerpi

I know that the typical values of Doppler coefficient over core life are about -1 *10^-5 Deltak/k/°F at BOL and -1.5 * 10^-5 Deltak/k/°F at EOL.

What are the value in SI units?

Are they the same, but in Kelvin?

Thanks,
Ken

2. Oct 18, 2004

### Morbius

Ken,

Since a Celsius degree [ not degree Celsius - but Celsius degree -
the size of the interval ] is 9/5 a Fahrenheit degree - you can do the conversion.

Celsius degree = 9/5 Fahrenheit degree.

Divide by "Celsius degree":

1 = 9/5 Fahrenheit degree / Celsius degree = 1.8 F deg / C deg

Since this equals 1 - you can multiply any quantity by it without
changing the value.

If you take the BOL value of 1.0 * 10^-5 Delta k/k/F deg and multiply by
the above, and divide out the units that cancel - you get

1.8 * 10^-5 Delta k/ k / C deg = 1.8 * 10^-5 Delta k /k / Kelvin deg

the latter part is because the size of the Kelvin degree equals the size
of the Celsius degree.

Dr. Gregory Greenman
Physicist LLNL