Observations of electrons in the Intense Pulse Neutron Source (IPNS) Rapid Cycling Synchrotron (RCS).

Conference · Thu Jan 01 04:00:00 EST 2004

OSTI ID:961324

Dooling, J C; Brumwell, F R; Czyz, W S; Harkay, K C; Lien, M K; McMichael, G E

In the process of accelerating protons from 50 to 450 MeV at 30 Hz, low-energy electrons are generated within the IPNS RCS vacuum chamber. Electrons from background gas stripping are detected using an Ionization Profile Monitor (IPM) to generate integrated, horizontal charge distributions of the single-harmonic bunch during acceleration. Recently, a Retarding Field Analyzer (RFA) was installed in the RCS to look for evidence of beam-induced multipacting by measuring the electrons ejected by the space charge of the beam. A wide-band, high-gain transimpedance amplifier has been built to observe time structure in the electron signal detected with the RFA. Though a noisy power supply prevented full I-V characteristics from being obtained, interesting features are observed; especially, after the period of phase modulation between the rf cavities that is deliberately introduced during the cycle. The phase modulation generates a longitudinal quadrupole oscillation in the bunch, which is believed to enhance beam stability. Preliminary results indicate that electron multipacting is not significant in the RCS. The effects of background gas neutralization are considered and details of the RFA measurements are presented.

• Research Organization: Argonne National Laboratory (ANL)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC02-06CH11357
• OSTI ID: 961324
• Report Number(s): ANL/IPNS/CP-110555
• Country of Publication: United States
• Language: ENGLISH

Related Subjects

43 PARTICLE ACCELERATORS
ACCELERATION
ACCELERATOR FACILITIES
AMPLIFIERS
BEAMS
CAVITY RESONATORS
ELECTRONS
IONIZATION
IPNS-I SYNCHROTRON
MODULATION
NEUTRON SOURCES
OSCILLATIONS
PROTONS
PULSES
QUADRUPOLES
RF SYSTEMS
SPACE CHARGE
STABILITY
STRIPPING
SYNCHROTRONS