HIAT2015 - List of Authors (Monma, T.)

Paper	Title	Page
MOPA16	Coherent Synchro-Beta Coupling in the KEK Digital Accelerator	1
	T. Monma KEK, Ibaraki, Japan
	The required acceleration voltage per turn in any circular accelerator is written by Vacc=ρC0dB/dt, where ρ, C0, and B are the bending radius, circumference of the orbit, and magnetic flux density, respectively. Since the guiding magnetic fields of the KEK Digital Accelerator, which is a fast cycling induction synchrotron, are excited sinusoidally, an ideal profile of Vacc is of half sine. From the engineering constraint of the current induction acceleration system, however, the output voltage is always constant between 1.5 kV and 2.0 kV. Thus the induction acceleration voltage pulse is discretely generated based on the specific pulse density program so as to satisfy a size of the required voltage integrated for a short time period. The induction acceleration cells are placed at the region where the magnitude of the momentum dispersion function is not zero but 1.4 m. It has been reported that the coherent motion of the beam centroid is strongly excited at the early stage of acceleration cycle . Discrete acceleration at the finite momentum dispersion function region is suspected to cause such a coherent motion. K.Takayama et al., "Induction acceleration of heavy ions in the KEK digital accelerator: Demonstration of a fast-cycling induction synchrotron", Phys. Rev. ST-AB 17, 010101(2014)

Paper

Title

Page

Coherent Synchro-Beta Coupling in the KEK Digital Accelerator

1

T. Monma
KEK, Ibaraki, Japan

The required acceleration voltage per turn in any circular accelerator is written by Vacc=ρC0dB/dt, where ρ, C0, and B are the bending radius, circumference of the orbit, and magnetic flux density, respectively. Since the guiding magnetic fields of the KEK Digital Accelerator, which is a fast cycling induction synchrotron, are excited sinusoidally, an ideal profile of Vacc is of half sine. From the engineering constraint of the current induction acceleration system, however, the output voltage is always constant between 1.5 kV and 2.0 kV. Thus the induction acceleration voltage pulse is discretely generated based on the specific pulse density program so as to satisfy a size of the required voltage integrated for a short time period. The induction acceleration cells are placed at the region where the magnitude of the momentum dispersion function is not zero but 1.4 m. It has been reported that the coherent motion of the beam centroid is strongly excited at the early stage of acceleration cycle *. Discrete acceleration at the finite momentum dispersion function region is suspected to cause such a coherent motion.
* K.Takayama et al., "Induction acceleration of heavy ions in the KEK digital accelerator: Demonstration of a fast-cycling induction synchrotron", Phys. Rev. ST-AB 17, 010101(2014)