tom formulas (ch 1-8)

Frequency formula

f=c/$\lambda$

Energy formula

E=h*f

C value

$3\cdot10^8$ m/s

Attenuation Formula

I=$I_0e^{-mx}$

Intensity distance relationship

$$\frac{I_1}{I_2}=\left(\frac{d_2}{d_1}\right)^2$$

1 Rad =

0.01 Gy

1 Rem =

0.01 sv

1 Roentgen

2.58$\cdot10^{-4}$ C/kg air

(Ionzation of air)

Planks Constant

h=$6.626\cdot10^{-34}$ J

h= 4.15$\cdot10^{-15}$ eV*s

1 eV

1.6$\cdot10^{-19}$ J

1 J

1 kg $\cdot\frac{m^2}{s^{^2}}$

Relationship between volts and coils

$$\frac{v_{s}}{v_{p}}=\frac{N_{s}}{N_{p}}$$

Finding mR distance + kvp

$$\frac{b^2}{a^2}$$

Finding mR mAs

$$\frac{a}{b}$$

Current units

Amp (Å) = 1 columb(electron) /1 sec

1 Å

$6.25\cdot10^{18}$ e/sec

Roentgen =

columns/kg*air

Find output useing kvp

$$\left(\frac{New}{Old}\right)^2$$

Find output useing mAs

$$\left(\frac{New}{Old}\right)$$

How to find transmitted protons

Attenuation formula

How to find Attenuation

After useinga attenuation formula subtract from total xray amount

Rule of 15

Increase kvp by 15% reduce mAs by half

Small EFS

0.6 mm

Large focal spot

Double small 1.2 mm

Current relationship to turns

Ip/Is = Ns/Np

Ripple Formula

$$\frac{\max-\min}{\max}\cdot100$$

HU to J

1 HU = 0.71 J

Power formula

P=VI

Ohms law

V=IR

Energy formula

E=Pt

Roentgen to C

2.58×10^-4

mAs to C

1mAs= .001 C