-1

According to this picture the Alpha particles in a cloud chamber are straight lines.

https://en.wikipedia.org/wiki/Cloud_chamber#/media/File:Cloud_chamber_bionerd.jpg

https://en.wikipedia.org/wiki/Cloud_chamber#/media/File:Cloud_chamber_bionerd.jpg

This is natural because this particles are approx. 4000 times heavier than electrons and the small size of the chamber respectively the relatively weakness of the magnetic field. My question is, was done an experiment with only Alpha particles in a homogeneous magnetic field and measured the deflection?

BTW the same question about neutrons and the evidence that the are not deflected undr the influence of an external magnetic field.

(There isn't a tag for Lorentz force)

HolgerFiedler
  • 10,334
  • Time, btw, didn't stop after they had invented the cloud chamber. You may want to take a look at a modern detector design like ATLAS or CMS. – CuriousOne Jul 20 '16 at 04:03
  • @CuriousOne Before the the PCs running hot from the big data the detectors are proofed with patricles of the same kind? For this results I''m searching – HolgerFiedler Jul 20 '16 at 04:11
  • CERN also invented the web browser... one might almost think they know how to serve web pages with data... just a suggestion for your "search". :-) – CuriousOne Jul 20 '16 at 04:14
  • 4
    I'm voting to close this question as off-topic because of insufficient research effort. – CuriousOne Jul 20 '16 at 04:19
  • @CuriousOne Instead of judging it would be nice to get answers from you. – HolgerFiedler Jul 20 '16 at 04:23
  • I am just noticing a pattern, that's all. – CuriousOne Jul 20 '16 at 04:25
  • 1
    ...are you asking if someone ever sent alpha radiation through a magnetic field? What is the significance of such an experiment? The behaviour of charges in magnetic fields is well-understood, why would alpha particles be special? – ACuriousMind Jul 20 '16 at 13:41
  • 1
    It is enough to know that cyclotrons were used to generate alpha beams, that alpha beams are regularly steered in accelerators or that mass spectrometers work on helium as well as on other elements. – dmckee --- ex-moderator kitten Jul 20 '16 at 14:09
  • @ACuriousMind See my comment resp. question http://physics.stackexchange.com/questions/268700/alpha-particle-moving-through-a-magnetic-field – HolgerFiedler Jul 20 '16 at 15:01
  • @ACuriousMind I would prefer to continue in a chat (in "slow motion", because I'm busy) – HolgerFiedler Jul 20 '16 at 15:08

1 Answers1

2

Related question Is an alpha particle's curvature in a magnetic field visible with a homemade cloud chamber?

You give no link for your photo and no details about the magnetic field imposed on the cloud chamber. Here is the case of alpha particles in a strong magnetic field:

alpha in mag field

An alpha particle is not readily deflected by a magnetic field. For this cloud chamber photograph a field of more than 4 Tesla was used (directed down into the picture.)

Neutrons are not charged and therefore their passage leaves no trace in a cloud chamber. The only interaction with a magnetic field would be through their magnetic moment and that is how the spin of the neutron was measured.

Community
  • 1
anna v
  • 233,453
  • For what it's worth on the neutron-deflection front, Asterix at LANSCE scatters neutrons from a sample in an 11 T magnet; it is not necessary to move the neutron detectors between "magnet on" and "magnet off." – rob Jul 20 '16 at 04:04
  • Anna The answers from your first link are not showing experimental evidence, are they? – HolgerFiedler Jul 20 '16 at 04:19
  • @rob could you please explain you comment. – HolgerFiedler Jul 20 '16 at 04:21
  • Anna The picture in the link "Here" has no source. – HolgerFiedler Jul 20 '16 at 04:25
  • I know, but it is a correct statement, and the site seems reliable. Here is a similar photo from a link in a book which I am sure will have the reference https://books.google.gr/books?id=PX87qqj5B2UC&pg=PA43&lpg=PA43&dq=alpha+particle+tracks+in+magnetic+field+bubble+chamber&source=bl&ots=PNlTqRDoAR&sig=ndbdW9lLp4b6qnGDND9JfyfOshI&hl=en&sa=X&ved=0ahUKEwi-7OnisoHOAhVIchQKHapiDrI4ChDoAQghMAI#v=onepage&q=alpha%20particle%20tracks%20in%20magnetic%20field%20bubble%20chamber&f=false – anna v Jul 20 '16 at 06:21
  • 1
    @HolgerFiedler If neutrons were deflected by a magnetic field, an 11 T field would do it. But passing a neutron beam through a strong magnetic field doesn't steer the neutrons: they end up on detectors in the same place. – rob Jul 20 '16 at 17:42
  • @rob This link seems to suggest that an inhomogeneous magnetic field deflects neutrons, doesn't it? – HolgerFiedler Jul 20 '16 at 18:24
  • @HolgerFiedler I thought the present question was about homogeneous magnetic fields? Of course inhomogeneous fields produce Stern-Gerlach steering. From your answer's reference, however, comes the sentence "Even with a [very large] gradient [in the magnetic field], the deflections produced are inconveniently small." – rob Jul 20 '16 at 18:41
  • @rob Why an inhomogeneous magnetic field deflect the neutron and a homogeneous doesn't? – HolgerFiedler Jul 20 '16 at 18:45
  • @HolgerFiedler Because the neutron has magnetic dipole moment but not electric charge. Particle Data Group gives references to the literature for both properties. – rob Jul 20 '16 at 19:02
  • @rob This is what I'm expecting. A magnetic field will deflect neutrons. The use of an inhomogeneous field has to show the two values of the spin. But if a inhomogeneous field will deflect neutrons than a homogeneous field has to do so. – HolgerFiedler Jul 20 '16 at 19:37
  • Let us continue this discussion in chat. – rob Jul 20 '16 at 21:08