3. Nuclear Mass and Stability, Nuclear Reactions and Notation, Introduction to Cross Section

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  • Опубликовано: 24 ноя 2024

Комментарии • 57

  • @mitocw
    @mitocw  4 года назад +10

    To report potential content errors, please use this form: forms.gle/8B2zcUvfCtgJdTdE7

  • @LCdrDerrick
    @LCdrDerrick 3 года назад +34

    I quite like this guy and his lectures! What else can we do during a lockdown and a curfew than bringing our physics and philosophy knowledge further?

  • @terrordance1735
    @terrordance1735 9 месяцев назад +2

    7:00 On Nuclear Notation
    - Explaining how BCNT (brain cancer therapy machine) works and why we made it this way
    - - Beryllium is a good material
    18:46 Reading the KAERI TABLE
    - Binding energy
    - - Mev/c^2 is how you do your mass mostly
    30:29 What is cross section
    - Solving an ODE for it, remember your boundary conditions
    - - Rate of exponential Attenuation
    36:19 Explaining previous terms more in depth (if you want some basics quick this is the place)
    - Excess mass means something only to our arbitrary way of measuring mass? (not actually physical phenomenon?)
    - - Examples (for finding binding energy)

  • @huanghan1911
    @huanghan1911 4 года назад +38

    The reason why people don't explicitly write for mass keV/c^2 but just keV is the tradition from high energy physics that we usually set c = hbar (reduced Planck const.) = 1. It's called natural unit. If we want these back we can just do a dimensional analysis and get the correct SI unit value.

    • @toketillubroke
      @toketillubroke 2 года назад

      A joule?

    • @Garage-physicist
      @Garage-physicist Месяц назад

      This absolutely not true, at least for nuclear physicists and nuclear engineers

    • @huanghan1911
      @huanghan1911 Месяц назад +1

      @@Garage-physicist go read more paper.

    • @Garage-physicist
      @Garage-physicist Месяц назад

      @@huanghan1911 I am a nuclear physicist at Lawrence Livermore National Lab. We don’t use natural units. I’ve never seen a nuclear engineer use natural units. It doesn’t make sense to do so when you’re performing calculations that need units. E.g., Oppenheimer could not assume that the critical mass of U235 is just “1”. Theoretical particle physicists do sometimes use natural units, however.

    • @huanghan1911
      @huanghan1911 Месяц назад

      @@Garage-physicist Good to know. I work in HEP theory and CMT at Cornell, we always use natural units to simplify the calculations, 99% of the time. Even in QCD, which is closely related to nuclear, we use natural unit. I never carry a c or hbar around when working on my equations. It's not that we don't make numerical calculation, it's just that there is a simple conversion that makes your life simpler. In condensed matter people also use hbar=1 very often.

  • @copernicohd
    @copernicohd 5 лет назад +17

    Thanks a lot to Michael short, what an amazing teacher. Hopefully one mine and MIT would paths cross

  • @justwhy-i6e
    @justwhy-i6e 2 месяца назад

    My boredom got me finishing three lectures in a day, I find this fun at the moment very good lectures

  • @rohitsrins
    @rohitsrins 3 года назад +3

    Just seeing this guy talk gives me goosebumps!!
    Would love to see him on Lex Friedman's podcast.. and listening to him on a long drive..

  • @cosmicnomad8575
    @cosmicnomad8575 2 года назад +3

    Love this class and this Instructor! Definitely learning a lot!

  • @whos1st
    @whos1st 3 года назад +10

    Thank you for posting this course. I am NOT a nuclear engineer, but I can at least learn some information and try to understand this complex science.

  • @johnwakamatsu3391
    @johnwakamatsu3391 Год назад

    I like watching these videos and worked as chemist for a government electrical and water utility for nearly 37 years. I am a proponent of thorium fission because it is less dangerous than uranium fission plants and this technology can be used to generate electricity for base loading. I believe that nuclear fusion will probably the long term energy solution, but is decades away for commercial use.

    • @idris4587
      @idris4587 Месяц назад +1

      Both Thorium and Uranium are equally as safe, it's the fact we use fast breeders and molten salt reactors for thorium and uranium which makes both our fissile reverses last thousands of years, and reduce the amount of waste products. Thorium alone doesn't make it safer. I agree about fission being a great baseload whilst other technologies mature

  • @GSGDaveyBoy
    @GSGDaveyBoy 3 года назад +2

    If Michael would just grow a little goatee and carry an MP5 he'd make a fantastic Gordon Freeman. Though a bit more chatty. I'm hooked on these lectures. He's great.

  • @PabloNevares
    @PabloNevares 2 года назад

    42:30 Love to see the help from an attentive student!

  • @spyhunter0066
    @spyhunter0066 2 года назад

    Excess mass is shown by small letter of delta A, but the mass defect is shown by capital letter Delta A.

  • @ianprado1488
    @ianprado1488 5 лет назад +5

    Thank you MIT :)

  • @CarYenta-1
    @CarYenta-1 2 года назад +1

    If the Cherenkov medium absorbed blue light, it may glow green a little.

  • @parrotraiser6541
    @parrotraiser6541 3 года назад +2

    It looks as though there's a set of spreadsheets that would be useful for nuclear engineers doing these calculations.
    Conversations between nuclear engineers and rocket scientists are likely to get confusing if they ever start talking about queues. There's probably a joke in there if you add a computer scientist to the mix.

  • @itspunit01
    @itspunit01 3 года назад +1

    He looks like Simon sinek... Btw love his lectures.. he is really awesome...❤️

  • @srikrishnanunna1
    @srikrishnanunna1 3 года назад

    While calculating the B.E. we dropped the errors, does that not incorrect our final values? I mean we only took the Median value of an e-, p+ and n, but not their errors.

  • @Hot_Hard_Cowboy
    @Hot_Hard_Cowboy 3 года назад +8

    I love this, I have been having trouble getting any kind of nuclear chemistry schooling from applying for colleges, but I can get the knowledge I want right here!

  • @ianprado1488
    @ianprado1488 5 лет назад +8

    However, I am slightly offended that big sigma is being used as a variable. 34:40

    • @BringJoyNow
      @BringJoyNow 3 года назад +1

      In class I once had to use big phi as variable, mathematical constant and as productory simble in the same system of equations.
      What a chaos that day went down

  • @farhanishraq5812
    @farhanishraq5812 2 года назад +2

    Man I wish i could attend MIT

    • @bunnyman6321
      @bunnyman6321 Год назад +1

      You in attendance now, virtually.

  • @montajadam7593
    @montajadam7593 2 года назад +2

    im eating my noodles at home and feeling like in MIT classes

  • @srikrishnanunna1
    @srikrishnanunna1 3 года назад +2

    How does these Excess Masses or Binding Energy values arrived at? I mean these are presented as legends here, but before that they should have been calculated experimentally right? What is that experiment? How do one understand the Instruments and their probabilities? Please refer me those, want to understand more on that.

    • @Otaku592
      @Otaku592 3 года назад +2

      Atomic/nuclear masses are usually measured by mass spectrometry. The most accurate methods being the measurement of resonance frequencies. See for example: en.wikipedia.org/wiki/Fourier-transform_ion_cyclotron_resonance
      I'm not an expert on this topic so there might also be other methods out there.

    • @srikrishnanunna1
      @srikrishnanunna1 3 года назад

      @@Otaku592 need to study on these, thanks 😊

  • @meowwwww6350
    @meowwwww6350 Год назад +1

    This is awesome 😎

  • @spectre256
    @spectre256 3 года назад +7

    "We can calculate the total energy of these nucleons when they are infinitely far apart (not drawn to scale)"
    Such a physics professor joke

  • @zack_120
    @zack_120 Год назад

    39:19 - So S-32 contains 16 of HYDROGENS, NOT protons?

  • @spyhunter0066
    @spyhunter0066 2 года назад

    Could you please tell me where you will mention about those graphical functions you've mentioned around the minute of 36.05 in the video? Cheers.

  • @joro8604
    @joro8604 9 месяцев назад

    Wow- i understood that!

  • @PriceCollect-ey7xl
    @PriceCollect-ey7xl Год назад

    Does it jamming the network I mean radio frequency

  • @FackitAllman
    @FackitAllman 3 года назад

    @44:45 I don't understand why he used 26.015 instead of the -26015.981

    • @ivan8126
      @ivan8126 3 года назад +2

      Probably because the unit on the screen was keV and the calculation used MeV. k (thousands) to M (millions) is a /1000 relationship.

  • @karamdabagh
    @karamdabagh 3 года назад +3

    i wonder if the class got the reference when he said "like voltron style"

  • @nataliiaproshunina-lc5gm
    @nataliiaproshunina-lc5gm Год назад

    I wish I' ve been in MIT

  • @gerym7782
    @gerym7782 5 лет назад +4

    thank you where can one have the course materials?

    • @mitocw
      @mitocw  5 лет назад +9

      As the video description states, the materials are available on MIT OpenCourseWare at: ocw.mit.edu/22-01F16.

  • @onderozenc4470
    @onderozenc4470 3 года назад

    I think He(4,2) can be better nominated as the gold number.

  • @PriceCollect-ey7xl
    @PriceCollect-ey7xl Год назад

    Neurone aging

  • @bumpty9830
    @bumpty9830 3 года назад +2

    Buster Bluth finally found his calling.

  • @lampa298
    @lampa298 4 года назад

    Bello

  • @PriceCollect-ey7xl
    @PriceCollect-ey7xl Год назад

    2D

  • @jpr333123
    @jpr333123 3 года назад +1

    I should have kept better track of time...

  • @BoboTheFett
    @BoboTheFett Год назад

    So if you don't know what the word attenuation means, and especially if you've never heard it, how the hell do you even get into a community college let alone MIT! lol

  • @moosepocalypse6500
    @moosepocalypse6500 Год назад +2

    I keep trying but I can't get this formula to work.
    BE=[16(1.007825)+16(1.008664)-(-0.0027928)-32]c²
    I don't get 271.764
    I get numbers that arent right at all, and a few orders of magnitude off on top of that. Is there anywhere I can get a more detailed explaination of this formula and maybe what I might be doing wrong? :/

    • @nicknass144
      @nicknass144 3 месяца назад +1

      When you have BE = [16(1.007825)+16(1.008664)-(-0.0027928)+32]c², you have units of [amu]*c².
      Keep the units attached to each:
      BE = [ 16(1.007825) [amu] + 16(1.008664) [amu] - ((-0.0027928)+32) [amu] ] * c².
      This comes out to
      BE = (0.291752 [amu]) * c^2.
      From there, you convert back to MeV:
      BE = (0.291752 [amu] * 931.49 [(MeV/c^2)/amu] * c^2
      Or
      BE = (0.291752 * 931.49 [MeV/c^2]) * c^2 (units of [amu] cancel)
      You can see that the c^2 units cancel and you're left with units of [MeV]. Carry out the multiplication to get
      BE = 271.76407 [MeV]

    • @moosepocalypse6500
      @moosepocalypse6500 3 месяца назад

      @@nicknass144 thanks for the help 🙂

    • @livlive5051
      @livlive5051 Месяц назад

      @@nicknass144 the actual problem is that she is having a extra Zero here (-0.0027928) instead of (-0.027928).