DarkLight radiation backgrounds

Journal Article · Thu Nov 07 04:00:00 EST 2013 · AIP Conference Proceedings

DOI:https://doi.org/10.1063/1.4829393· OSTI ID:22280663

Kalantarians, N. ^[1]

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1. Department of Physics, Hampton University, Hampton VA 23668 (United States)

We report measurements of photon and neutron radiation levels observed while transmitting a 0.43 MW electron beam through millimeter-sized apertures and during beam-on, but accelerating gradient RF-on, operation. These measurements were conducted at the Free-Electron Laser (FEL) facility of the Jefferson National Accelerator Laboratory (JLab) using a 100 MeV electron beam from an energy-recovery linear accelerator. The beam was directed successively through 6 mm, 4 mm, and 2 mm diameter apertures of length 127 mm in aluminum at a maximum current of 4.3 mA (430 kW beam power). This study was conducted to characterize radiation levels for experiments that need to operate in this environment, such as the proposed DarkLight Experiment. We find that sustained transmission of a 430 kW CW beam through a 2 mm aperture is feasible with manageable beam-related backgrounds. We also find that during beam-off, RF-on operation, field emission inside the niobium cavities of the accelerator cryomodules is the primary source of ambient radiation.

• OSTI ID: 22280663
• Journal Information: AIP Conference Proceedings, Journal Name: AIP Conference Proceedings Journal Issue: 1 Vol. 1563; ISSN APCPCS; ISSN 0094-243X
• Country of Publication: United States
• Language: English

Related Subjects

43 PARTICLE ACCELERATORS
ACCELERATOR FACILITIES
ALUMINIUM
APERTURES
BEAM MONITORING
BEAM MONITORS
BEAM TRANSPORT
CEBAF ACCELERATOR
ELECTRON BEAMS
FERMILAB ACCELERATOR
FIELD EMISSION
FREE ELECTRON LASERS
MEV RANGE
NEUTRONS
NIOBIUM
PHOTONS
RF SYSTEMS