b.tchy question - syclotron or whatever (1 Viewer)

[Bannanafish]

yep that's right takuya

i did my work experience in yr 11 at fermilab i should know

 

[xiao1985]

Originally posted by Bannanafish
synchotrons don't have one big field
they boost like linear accelerators

the path of the partical isn't really a circle, more like a polygon

are u sure on that?? cuz i fink syncrotron r jsut 2 Dee's..... joined together... much like cyclotron but does not accelerate tangentially.......

 

[t-i-m-m-y]

sheesh yes it was a tricky question

i used the relationships:

f=mv^2/r and related this to f=ma... as mass increases relativistically given by the lorentz transformations, the force required to keep the radius constant increases... as f=ma 'doh!

now u gotta relate the increase in force and draw the corelation using the relationship: f=qvb.. stuff sintheta as it is always 1 ie. constant

therefore b must increase to maintain the the same radius... oh yeah also use the formula e=mc^2 and relate it to the kinetic energy of the moving particle.... using K.E= mv^2/2

wow.. i luv my band 6 answer

 

[Takuya]

Originally posted by Bannanafish
yep that's right takuya

i did my work experience in yr 11 at fermilab i should know

NICE!!! I am so relieved

I read somewhere that synchrotrons work like linear accelerators so I used F=ma.

But I put a sidenote about centripetal force in a different case. I hope they exclude the sidenote.

 

[Bannanafish]

wow lorenz transformations

good work

 

[B.Rabbit]

I had NO CLUE...

 

[Constip8edSkunk]

Originally posted by xiao1985
are u sure on that?? cuz i fink syncrotron r jsut 2 Dee's..... joined together... much like cyclotron but does not accelerate tangentially.......

cyclotron has 2 Ds, synchrontron is a series of tubes in a circular shape broke up into joints and teh B field increases sychonously with the velocity so the radius doesnt increase liek a cyclotron

 

[...]

Originally posted by ND
Yep i talked about mass dilation. Instead of being F=mv^2/r, it would be F=mv^2/sqrt(1-v^2/c^2)r.

i did that...


but with length contradioin..
-_-

 

[t-i-m-m-y]

Originally posted by ...

but with length contradioin..
-_-

to put it in context.. we also have relativistic velocities because length and time contracts.. thus there are also relativistic velocities for each frame of reference lol i shall stop. not required:d

 

[Constip8edSkunk]

hmm i did what nd did too... i graphed the curve as well Hahahahaa... but i didnt mention that F=qvB formula, cuz i just assumed B to be proportional to F... hmmm ... hope i don't lose too many marks there...

 

[freaking_out]

one thing for sure...ppl, who did the Q2Q option had an advantage.

 

[Hai]

that was the only question of the exam that really confused me. my friend who did quanta to quarks said that its in that option topic. i had no idea cos i did age of silicon. but if this is true (could anyone verify?) then this is an extremely unfair question as this would have disadvantaged at least half the candititure. gees and i thought hsc exams were supposed to be fair.....


anyways, i came up wif this explaination, no one seems to have the same one as me, could anyone comment?:
When the electron is travelling close to the speed of light, length contraction must be taken into account. Relative to the electron, the magnetic field appears to distort, contracting in the direction of travel. (put in length contraction formula). For a charge to undergo uniform circular motion within a magnetic field, the magnetic field must be uniform and this contraction causes the field to become un-uniform. Thus to account for this, the magnetic field around the electron must distort to accomodate for this, or more specifically, the magnetic field must be stretched around the electron so that the relative to the electron, the magnetic field is uniform, ensuring that the electron undergoes uniform circular motion.,

 

[underthesun]

I read something about mass dilation in particle accelerators, on some railgun experiment somewhere. Apparently they do, as I recall.

But taking into account that all the past relativity questions always had to talk about relativity in the question itself, this does not seem to be a relativity question. Hence, it is unlikely that relativity needs to be taken into account.

wishful thinkingl, wishful thinking. I feel a disturbance in the force.

 

[Kent_Cadarn]

It was an easy question if you could see the relationship, just like Thomson's
mv^2/r = qvB
r = mv/qB so as v increases (i.e. pasticle is accelerated) then B must increae so that r remains constant

 

[d00d]

yeah thats right its in Q2Q, i guess it helped me a lil... not a real advantage tho coz it told you everything u needed to know in the question.

it looked pretty difficult but i think they pretty much guided u to the answer by telling u it travels to near the speed of light.

 

[walla]

i do q2q and i'd be pretty pissed off at that question if i didn't do that option. having said that though, it wasn't really something we studied....i think most people would have logically figured out the answer using mass dilation and knowledge of forces from the core topics

 

[Viper]

Come on guys.... the Q2Q students didn't have any advantage.... There is nothing in the Q2Q syllabus that mentions the effects of particles at high speeds.... The question was merely combining a bit of Space (mass dilation) and Motors & Generators (Alternating Magnetic Fields).

At the time of the exam, i didn't even think about the centripedal force, but one thing that i did mention (that none of you guys have mentioned on here) is Newtons 2nd Law.... If ther mass is increasing with velocity, then a greater magnetic force must be supplied to continue to acclerate the electron.... according to F=ma...

Cheers

 

[Bannanafish]

i did F=ma, increasing mass, ned more forece to accelerate further
F=qvB ther force will increase due to increase of velocity but still needs more because of mass dilation, so increase B

i really think technically you can't use centripetal force cause sychrotrons use boosting not a big magnetic field and hence the particles don't travel in circles

also since the magnetic stuff was in q2q i think they might focus on the mass dilation for this q

 

[t-i-m-m-y]

yes.... Q2Q guys should not have an advantage- seeing as it was part of the core.. the stuff in the core section will be from the core section.. silly as it may sound.. that is true.. therefore u just need to make the basic correlations i mentioned in my earlier post

 

[Jimmoi]

Originally posted by Bannanafish
i did F=ma, increasing mass, ned more forece to accelerate further
F=qvB ther force will increase due to increase of velocity but still needs more because of mass dilation, so increase B

Exactly how I answered.


Jimmoi


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