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    (Original post by mik1w)
    no analogies for the accelerators, just other ones

    for example with a spring system and capacitorsin series or parallel (capacitance and the spring constant), or decay of a capacitor by discharge through a resistor and redioactive decay,
    but you have to know the advantages of one on the others for example I'm goonna post them here
    cyclotrons needs a smaller area than linac to accelerate a particle through the same pd
    synochrotron has taken acount for the increase of mass so that the frequency and the magnetic field can be synochronised so that relativity in increase in mass problem is solved while in the cyclotron whent he particle aproaches the speed of light it mass increases and so it stops accelerating and it becomes out of phase with the changing electric field

    so who wanna do the chambers thingie
    there are bubble chamber
    sparkchamber
    cloud chamber and drift chamber
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    good explanation of the cyclotron
    is the synchotron just a cyclotron with a varying magnetic field to compensate?
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    (Original post by mik1w)
    good explanation of the cyclotron
    is the synchotron just a cyclotron with a varying magnetic field to compensate?
    yeah but also the synochrotron doesn't have a d chambers it looks like a ring
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    ah okay so how does it get accelerated? is there just a DC field on one part of the ring?
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    Synchrotrons are huge (eg radius of 1km, so a disadvantage in building).
    Other disadvantages - because the particles are changing velocity, it must be continuously accelerated to move them in a circular path - but accelerating charged partciles emited electromagnetic radiation, so the particles also lose energy all the time, meaning more and more energy must be supplied (infact a lot of the work done on particles does not increase the k.e. but simply maintains it).
    This is also why they're so big, because a=v^2/r, so a large radius = less acceleration (so less energy loss due to radiation).
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    (Original post by mik1w)
    ah okay so how does it get accelerated? is there just a DC field on one part of the ring?
    I've heard is looks like the linac I mean it's not continouse it got gabs between cylinders
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    (Original post by habosh)
    I've heard is looks like the linac I mean it's not continouse it got gabs between cylinders
    Yep, that's right- it's AC, and the frequency of the alternating p.d. increases to keep it synchronised when particles pass through.
    The speed of particles increases, which means the magnetic field strength must increase (as it's the centripetal force), and this means that the frequency must increase.

    F = Bqv = mv²/r
    Bq = mv/r ... (B proportional to v)

    and f =Bq/2πm ..(f proportional to B)
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    (Original post by endeavour)
    Yep, that's right- it's AC, and the frequency of the alternating p.d. increases to keep it synchronised when particles pass through.
    do you have any link about comparession between various trypes of particle detectros??
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    This is quite good: http://en.wikipedia.org/wiki/Particle_accelerators
    but there's probably a lot of info which you won't need.
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    (Original post by endeavour)
    This is quite good: http://en.wikipedia.org/wiki/Particle_accelerators
    but there's probably a lot of info which you won't need.
    THANX ALOT
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    So ac, like it attracts the particle towards itself then when the particle is at the mid point it switched to repel it away ?
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    I have no idea how to tell if a track in one of the chambers means a particle is positively or negatively charged!
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    (Original post by kat_r)
    I have no idea how to tell if a track in one of the chambers means a particle is positively or negatively charged!
    Something to do with Fleming's left-hand Rule maybe?
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    the trail of the particle is distinctive for positive/neutral/negatively charged particles. I think it's explainned in th NAS[not nas7232] book.
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    I'm sure this has been asked before, but seeing i'm a terrible skim reader, i probably missed it..

    Anyway, there was a question asking what the disadvantage of the cyclotron was, compared to the linac. I asked my teacher and she didn't know (to be fair.. shes a rubbish teacher) and yeah.. does anyone know?
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    wait endauvor just said it it's that in circular acelerator particles emits radaition whilke in linac it doesn't
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    (Original post by kat_r)
    I have no idea how to tell if a track in one of the chambers means a particle is positively or negatively charged!
    I guess you're talking about particle traces cloud chamber track? As was already mentioned, you use Fleming's left hand rule.

    Take a look at this example (see attachment). Let's say you've been told it's a positron and you want to work out the magnetic field direction.

    you can see the particle's motion becomes more curved after it passes through the white matter (the bottom half)- ie you can deduce the positron's direction is downwards (from the top to the bottom of the picture), because when it passes through the block, it slows down.
    Using fleming's l.h. rule, the centripetal force is towards the right, the current is downwards (as positron = positive = conventional current), and so the magnetic field must be going into the image.
    Attached Images
     
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    do we need to know about springs in series and parrallel cos our teacher never taught us about that
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    yea and u have to make an anology with reisitors me thinkz
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    i found this - http://www.thestudentroom.co.uk/arch.../t-116999.html

    its just that it goes on to say about springs in parrallel etc which we havent leanrt about and i cant c on the syllabus but i know about capacitors is parrallel etc.

    but on the phy 6 syllabus it mentions the comparisons but focuses on energy stored and f=kx and v=Q/C
 
 
 
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