Recent content by Denver Dang

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    Intro Physics Photon and charged particle interactions with matter

    That is kind of the deal. My supervisor has told me that I (and other PhD students) would have to find textbooks etc. on our different topics. And then they would go through the material as well. So basically my topic would be about how radiation is deposited into matter (i.e. the body of a...
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    Intro Physics Photon and charged particle interactions with matter

    I am about to teach some of an introductory course for bachelor students in the field of medical physics. More specifically the topic "Photon and charged particle interactions with matter" in respect to radiation therapy (again, medical physics). I know there are a lot of topics within radiation...
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    3D-CRT vs. IMRT in Radiotherapy

    Thank you very much for the great explanation :)
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    3D-CRT vs. IMRT in Radiotherapy

    Ahhh, okay... So MLCs can actually be used in both cases, but it is actually the treatment planning system that is the main difference between 3D-CRT and IMRT ?
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    3D-CRT vs. IMRT in Radiotherapy

    Hmmm, I actually thought, that MLCs were used in 3D-CRT, just as a static procedure, like it was done with lead blocks years back. But that is not the case ? MLCs are IMRT only ?
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    3D-CRT vs. IMRT in Radiotherapy

    I'm having some trouble truly understanding the difference between these two. As far as I know, the 3D-CRT is just beams from different angles, where you can modulate the beam intensity by lead blocks custom made for each patient, cut out to fit the outline of a tumour. IMRT is when the...
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    Baryon acoustic oscillations and sound horizon

    I'm having some trouble understand this correctly, so I was hoping someone could enlighten me a bit :) Okay, so in the early Universe most of the hydrogen and helium was formed, and then kept in equilibrium, and ionized via photons. So we have a plasma of baryonic matter, including dark matter...
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    Boltzmann equation for the early Universe

    hehe, thank you for the answers :) It really made it a bit easier to understand.
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    Boltzmann equation for the early Universe

    Ahhh, a quite good note actually. A bit better explained than in Dodelson :) I do have a couple of questions if that is okay? 1. The left-hand side of my equation tells me how the number density of the chosen particle evolves with time. So if the right-hand side is equal to zero (As is the...
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    Boltzmann equation for the early Universe

    I'm currently reading about the Boltzmann equation, used for the early Universe. The equation I end up with, after some simplifications is the following: \begin{equation} a^{-3}\frac{d}{dt}\left(n_1a^3\right) = n_1^{(0)}n_2^{(0)}\langle\sigma v\rangle\left[\frac{n_3 n_4}{n_3^{(0)}n_4^{(0)}} -...
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    Creation of spinning neutron stars and pulsars

    Once again, thank you very much :) It was very informative.
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    Creation of spinning neutron stars and pulsars

    Thanks for the enlightening, it really made many of my questions clear :) But, if you don't mind, I would like to know the neutrino thing, if it's not too much to ask? I've read a lot of things about it, but it hasn't really been very detailed, so I pretty much just end up getting something...
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    Creation of spinning neutron stars and pulsars

    I've gotten a bit confused about the creation of the neutron star/pulsar, so I was hoping someone could point me in the right direction :) As fusion stops, when reaching the iron phase, the outer layers (hydrogen, helium, carbon... etc.) gets pulled in-wards do to gravity. This creates a bounce...
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    Calculate the age of the Universe at a temperature

    Ah, I see what you mean now. Sorry for the confusing on my part. Thank you very much :)
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    Calculate the age of the Universe at a temperature

    Hmmm, I'm not sure I follow. How does that help me ?
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