Identity area
Reference code
Heritage collection CERN-OBJ-CERN-OBJ-AC-022
Title
magnetic horn
Date(s)
Level of description
Item
Extent and medium
Object
Context area
Repository
Archival history
Immediate source of acquisition or transfer
Content and structure area
Scope and content
Neutrinos and antineutrinos are ideal for probing the weak force because it is effectively the only force they feel. How were they made? Protons fired into a metal target produce a tangle of secondary particles. A magnetic horn like this one, invented by Simon Van der Meer, selected pions and focused them into a sharp beam. Pions decay into muons and neutrinos or antineutrinos. The muons were stopped in a wall of 3000 tons of iron and 1000 tons of concrete, leaving the neutrinos or antineutrinos to reach the Gargamelle bubble chamber. A simple change of magnetic field direction on the horn flipped between focusing positively- or negatively-charged pion beams, and so between neutrinos and antineutrinos.
Appraisal, destruction and scheduling
Accruals
System of arrangement
Conditions of access and use area
Conditions governing access
Public
Conditions governing reproduction
Language of material
Script of material
Language and script notes
Physical characteristics and technical requirements
15 000 CHF
Finding aids
Generated finding aid
Allied materials area
Existence and location of originals
Available, 282.
Existence and location of copies
Related units of description
Notes area
Alternative identifier(s)
CDS number
43925
Object Number
OBJOBJ 0000200
