While exploring some of the tracks I noticed they start rotating in a small helix until the distance from the middle increase enough, then they stop rotating and continue to move straight as if the magnetic field dropped. What am I missing?
", "messages": [ { "id": "348794", "postDate": "06/27/2018 10:01:48", "content": "While exploring some of the tracks I noticed they start rotating in a small helix until the distance from the middle increase enough, then they stop rotating and continue to move straight as if the magnetic field dropped. What am I missing?
", "rawMarkdown": "While exploring some of the tracks I noticed they start rotating in a small helix until the distance from the middle increase enough, then they stop rotating and continue to move straight as if the magnetic field dropped. What am I missing?", "votes": null }, { "id": "348804", "postDate": "06/27/2018 10:31:02", "content": "trackml-participant-document-particle-v1.0 page.9
", "rawMarkdown": "[trackml-participant-document-particle-v1.0][1] page.9\n\n\n [1]: https://kaggle2.blob.core.windows.net/forum-message-attachments/321278/9331/trackml-participant-document-particle-v1.0.pdf", "votes": null }, { "id": "348808", "postDate": "06/27/2018 10:41:29", "content": "Momenta px, py and pz change during scattering. If px and py get small values (relatively to pz) a particle moves almost perpendicular to XY plane and practically stops rotating in magnetic field.
", "rawMarkdown": "Momenta px, py and pz change during scattering. If px and py get small values (relatively to pz) a particle moves almost perpendicular to XY plane and practically stops rotating in magnetic field.", "votes": null }, { "id": "348811", "postDate": "06/27/2018 10:47:31", "content": "Thanks
", "rawMarkdown": "Thanks", "votes": null }, { "id": "348824", "postDate": "06/27/2018 11:09:01", "content": "...also at large z the field lines are diverging, they are not parallel to the z axis any more, meaning they tend to be more parallel to the particles (coming more or less from 0 0 0), hence a smaller deviation
", "rawMarkdown": "...also at large z the field lines are diverging, they are not parallel to the z axis any more, meaning they tend to be more parallel to the particles (coming more or less from 0 0 0), hence a smaller deviation", "votes": null }, { "id": "348831", "postDate": "06/27/2018 11:12:39", "content": "i have a related question.
\n\nNow in a single event, b_field(x,yz) is not constant.
\n\nfor a fixed location, is magnetic field constant for different events?\ni.e is b_field(x,y,z | event_i ) = b_field(x,y,z | event_j ) , given a fixed x,y,z
", "rawMarkdown": "i have a related question.\n\nNow in a single event, b_field(x,yz) is not constant.\n\nfor a fixed location, is magnetic field constant for different events?\ni.e is b_field(x,y,z | event_i ) = b_field(x,y,z | event_j ) , given a fixed x,y,z", "votes": null }, { "id": "348843", "postDate": "06/27/2018 11:39:28", "content": "Yes, field is constant in time. you can \"measure it\" using the tracks themselves.\nMaybe the organizer can post the actual field map: guessing mag-field and materials is not really part of the challenge (at least in my view)
", "rawMarkdown": "Yes, field is constant in time. you can \"measure it\" using the tracks themselves.\nMaybe the organizer can post the actual field map: guessing mag-field and materials is not really part of the challenge (at least in my view)", "votes": null }, { "id": "363659", "postDate": "07/29/2018 19:41:03", "content": "That makes sense. Can we assume that the B-field is circularly symmetric around the z-axis?
", "rawMarkdown": "That makes sense. Can we assume that the B-field is circularly symmetric around the z-axis?", "votes": null }, { "id": "363663", "postDate": "07/29/2018 19:49:04", "content": "It is slightly off axis, one might see some phi dependence due to this
", "rawMarkdown": "It is slightly off axis, one might see some phi dependence due to this", "votes": null } ], "comments": [ { "id": 348804, "author_name": "outrunner", "author_url": "", "post_date": "06/27/2018 10:31:02", "content": "trackml-participant-document-particle-v1.0 page.9
", "votes": null, "replies": [ { "id": 348811, "author_name": "yuval6967", "author_url": "", "post_date": "06/27/2018 10:47:31", "content": "Thanks
", "votes": null, "replies": [] } ] }, { "id": 348808, "author_name": "sionek", "author_url": "", "post_date": "06/27/2018 10:41:29", "content": "Momenta px, py and pz change during scattering. If px and py get small values (relatively to pz) a particle moves almost perpendicular to XY plane and practically stops rotating in magnetic field.
", "votes": null, "replies": [ { "id": 348824, "author_name": "droussea", "author_url": "", "post_date": "06/27/2018 11:09:01", "content": "...also at large z the field lines are diverging, they are not parallel to the z axis any more, meaning they tend to be more parallel to the particles (coming more or less from 0 0 0), hence a smaller deviation
", "votes": null, "replies": [] }, { "id": 363659, "author_name": "dotdashdashdash", "author_url": "", "post_date": "07/29/2018 19:41:03", "content": "That makes sense. Can we assume that the B-field is circularly symmetric around the z-axis?
", "votes": null, "replies": [] }, { "id": 363663, "author_name": "droussea", "author_url": "", "post_date": "07/29/2018 19:49:04", "content": "It is slightly off axis, one might see some phi dependence due to this
", "votes": null, "replies": [] } ] }, { "id": 348831, "author_name": "hengck23", "author_url": "", "post_date": "06/27/2018 11:12:39", "content": "i have a related question.
\n\nNow in a single event, b_field(x,yz) is not constant.
\n\nfor a fixed location, is magnetic field constant for different events?\ni.e is b_field(x,y,z | event_i ) = b_field(x,y,z | event_j ) , given a fixed x,y,z
", "votes": null, "replies": [ { "id": 348843, "author_name": "vininn", "author_url": "", "post_date": "06/27/2018 11:39:28", "content": "Yes, field is constant in time. you can \"measure it\" using the tracks themselves.\nMaybe the organizer can post the actual field map: guessing mag-field and materials is not really part of the challenge (at least in my view)
", "votes": null, "replies": [] } ] } ], "raw_markdown_by_id": { "348794": "While exploring some of the tracks I noticed they start rotating in a small helix until the distance from the middle increase enough, then they stop rotating and continue to move straight as if the magnetic field dropped. What am I missing?", "348804": "[trackml-participant-document-particle-v1.0][1] page.9\n\n\n [1]: https://kaggle2.blob.core.windows.net/forum-message-attachments/321278/9331/trackml-participant-document-particle-v1.0.pdf", "348808": "Momenta px, py and pz change during scattering. If px and py get small values (relatively to pz) a particle moves almost perpendicular to XY plane and practically stops rotating in magnetic field.", "348811": "Thanks", "348824": "...also at large z the field lines are diverging, they are not parallel to the z axis any more, meaning they tend to be more parallel to the particles (coming more or less from 0 0 0), hence a smaller deviation", "348831": "i have a related question.\n\nNow in a single event, b_field(x,yz) is not constant.\n\nfor a fixed location, is magnetic field constant for different events?\ni.e is b_field(x,y,z | event_i ) = b_field(x,y,z | event_j ) , given a fixed x,y,z", "348843": "Yes, field is constant in time. you can \"measure it\" using the tracks themselves.\nMaybe the organizer can post the actual field map: guessing mag-field and materials is not really part of the challenge (at least in my view)", "363659": "That makes sense. Can we assume that the B-field is circularly symmetric around the z-axis?", "363663": "It is slightly off axis, one might see some phi dependence due to this" }, "source": "meta" }