LazyRoot

Archive for the ‘Physics’ Category

May
7

Debye shielding and the plasma criteria

By Dejan | Plasma Physics | Add comment

So in previous post I defined what plasma is and today I will define some additional criteria that are required for plasma formation.  These criteria are necessary to distinguish between an ionized gas and plasma itself.  Before we do this we need to define the quantity known as Debye length which is the measure of the shielding present in plasma.  This type of shielding is called Debye shielding. What happens inside the plasma is that we have a lot of positively charged particles (ions) and negatively charged particles (electrons) floating around.  If we insert a positively charged sphere into the plasma all of the electrons would rush to it and neutralize the charge.  So we would end up with our positive sphere and a bunch of electrons right around it and the number of electrons would be equal to the charge required to neutralize the positive charge.

More…

May
3

Plasma, what is it?

By Dejan | Plasma Physics | Add comment

As I mentioned couple of days ago I will be going trough my plasma books and witting about things I go over.  So start of the first post I guess I should give a brief introduction to plasmas.

Currently there are four know states of mater, plasma is one of them.  Most people are familiar with solid, liquid and gaseous states of mater, but very few people know much about plasma.  It is said that about 99% of all matter in universe is in plasma state, yet on Earth we see very little plasma.  This is because the thing that makes mater transition from one state to next is temperature.  In the case of water ice is the solid state and it occurs when temperature is below 0C, liquid water occurs between 0-100C and above 100C is vapor or water’s gas state.  In order to make water into plasma we would have to raise the temperature of the water to thousands of degrees, which is very impractical here on Earth, but on Sun and billions of other stars it’s a completely different story.

More…

Nov
25

PhD is a go

By Dejan | Physics | Add comment

Went to the graduate advisor’s office today to check-up on my graduate application status and it turns out that she was writting a congratulatory letter to me :) .  This means I’m officially in the program.  I had to run to physics department and get some signatures, since apparently the physics department has to agree to transfer.  Hopefully all the paperwork will be done soon, otherwise I’ll be stuck with some “late transfer” fee.  All-in-all great news.

Sep
26

Plasma physics has started

By Dejan | Physics | Add comment

Started my first class on Wednesday.  I’m not in the PhD program yet, but I think there is a good chance I’ll get in.  I will mostly be in classes on Mondays and Wednesdays, which means I work from home in the morning.  As far as the class goes, so far so good, the class is an “Introduction to plasma physics”.  It’s a senior level class, so it’s not intended for graduate students, but it looks like a perfect class to start my plasma physics career in at the UW.  Hopefully next quarter I will be taking a graduate CFD class, which is when the real work starts.