SPASE.info

Optical Photometer

ResourceID
spase://SMWG/Instrument/BARREL/OpticalPhotometer

Description

"Objective: To detect the flux of visible light at wavelengths near 486.1 nm during a relativistic electron precipitation event. This will determine whether there are protons accompanying the precipitating electrons. (emissions near 486.1 nm are a signature of precipitating protons.) Correlated proton and relativistic electron precipitation would support scattering by EMIC (electromagnetic ion cyclotron) waves at the precipitation mechanism." (Ref. 1) "How it works: The photons are collected through a collimator tube that restricts the field of view to a cone approximately five degrees full width angle, tilted at 35 degrees from the zenith. A 2.5 nm wide Hβ filter is mounted near the base of the collimator. Each photon incident on the two inch diameter photomultiplier tube results in the generation of a charge pulse. These pulses then go into a charge-sensitive pre-amplifier, discriminator, and shaping electronics, producing a TTL pulse for each incident photon. By counting the number of pulses, the flux of the precipitating protons can be determined." (Ref. 1)

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Details

Version:2.2.2

Instrument

ResourceID
spase://SMWG/Instrument/BARREL/OpticalPhotometer
ResourceHeader
ResourceName
Optical Photometer
ReleaseDate
2011-06-06 00:00:00Z
Description

"Objective: To detect the flux of visible light at wavelengths near 486.1 nm during a relativistic electron precipitation event. This will determine whether there are protons accompanying the precipitating electrons. (emissions near 486.1 nm are a signature of precipitating protons.) Correlated proton and relativistic electron precipitation would support scattering by EMIC (electromagnetic ion cyclotron) waves at the precipitation mechanism." (Ref. 1) "How it works: The photons are collected through a collimator tube that restricts the field of view to a cone approximately five degrees full width angle, tilted at 35 degrees from the zenith. A 2.5 nm wide Hβ filter is mounted near the base of the collimator. Each photon incident on the two inch diameter photomultiplier tube results in the generation of a charge pulse. These pulses then go into a charge-sensitive pre-amplifier, discriminator, and shaping electronics, producing a TTL pulse for each incident photon. By counting the number of pulses, the flux of the precipitating protons can be determined." (Ref. 1)

Acknowledgement
Contacts
RolePerson
1.PrincipalInvestigatorspase://SMWG/Person/Robyn.Millan
2.CoInvestigatorspase://SMWG/Person/Robert.P.Lin
3.CoInvestigatorspase://SMWG/Person/Michael.P.McCarthy
4.CoInvestigatorspase://SMWG/Person/Mary.K.Hudson
5.CoInvestigatorspase://SMWG/Person/Mikhail.I.Panasyuk
InformationURL
Name
Reference 1
URL
http://www.dartmouth.edu/~rmillan/minis/MINIS.Instrumentation.pdf
Description

BARREL instrument documentation, quoted for above instrument description.

InstrumentType
EnergeticParticleInstrument
InstrumentType
Photometer
InvestigationName
Balloon Array for RBSP Relativistic Electron Losses (BARREL)
ObservatoryID
spase://SMWG/Observatory/BARREL