17–22 May 2026
C.I.D
Europe/Zurich timezone

The collimator system for reducing the dark current in NSRRC photoinjector

TUP2670
19 May 2026, 16:00
2h
C.I.D

C.I.D

Deauville, France
Board: Tuesday wine: WC07
Poster Presentation MC2.A08: Photon sources: Linear Accelerators Poster session

Speaker

Yi-Chieh Chang (National Synchrotron Radiation Research Center)

Description

The NSRRC photoinjector generates ultrashort electron beams for the production of superradiant radiation in the 100–500 μm wavelength range using a gap tunable U100 planar undulator. The accelerator consists of an S band, laser driven photocathode RF gun equipped with a compensation solenoid, followed by a 5 m long linear accelerator. Sub picosecond electron bunches are achieved through velocity bunching in the linac. Under specific operating conditions, electrons emitted from the cathode surface may be accelerated to high energies independently of the main beam, which continues to gain energy in the linac. These stray electrons can impact the vacuum chamber, producing unwanted radiation that poses risks to both accelerator components and radiation safety. To suppress dark current, a collimator was installed between the photocathode gun and the linac to intercept these electrons prior to downstream transport. Experimental measurements and numerical simulations are presented, demonstrating the effectiveness of the collimator system in reducing dark current.

Paper status Proceeding files received

Author

An-Ping Lee (National Synchrotron Radiation Research Center)

Co-authors

Hsin-Pai Hsueh (National Synchrotron Radiation Research Center) Ming-Chang Chou (National Synchrotron Radiation Research Center) Shan-You Teng (National Central University) Dr Wei-Yuan Chiang (National Synchrotron Radiation Research Center) Yi-Chieh Chang (National Synchrotron Radiation Research Center)

Presentation materials