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Kumar, V.

Paper Title Page
TUPMA038 Start-up of an FEL Oscillator from Shot Noise 163
 
  • V. Kumar, S. Krishnagopal
    RRCAT, Indore (M. P.)
  • W. M. Fawley
    LBNL, Berkeley, California
  
  In free-electron laser (FEL) oscillators, as in self-amplified spontaneous emission (SASE) FELs, the build-up of intra-cavity power starts from shot noise resulting from the discreteness of charge in the electron bunch. It is important to do the start-up analysis for the build-up of intracavity power in order to fix the macropulse width from the electron accelerator such that the system reaches saturation. In this paper, we show that one can use the time-dependent oscillator code GINGER [1] to perform this anlysis. we present results of this analysis for the parameters of the Compact Ultrafast TErahertz FEL (CUTE-FEL) [2] being built at RRCAT.

1. W. Fawley, 'A user Manual for GINGER and Its Post-Processor XPLOTGIN}},LBNL-49625-Rev. I' ed., Lawrence Berkley National Laboratory (2004).2. S. Krishnagopal et al., Proceedings of FEL conference (2006) 496.

 
TUPMA039 Comparison of Codes for Smith-Purcell FEL 166
 
  • V. Kumar
    RRCAT, Indore (M. P.)
  • K.-J. Kim
    ANL, Argonne, Illinois
  • D. Li
    ILT, Suita, Osaka
  
  Smith-Purcell FELs using low energy electron beam are being seen as attractive option for a compact source of coherent Terahertz ratiation. Recently, Kumar and Kim [1] have performed numerical simulation of Smith-Purcell free-electron lasers (SP-FELs) based on a computer code using Maxwell-Lorent equations. Li et al. [2], and Dounhue et al. [3] have performed calculations using PIC codes. In this paper, we present a comparision of these methods and compare results obtained using different codes.

1. V. Kumar et al., Phys. Rev. E 73, 026501 (2006). 2. D. Li et al., Phys. Rev. ST Accel. Beams 9, 040701 (2006). 3. J. T. Donohue et al., Phys. Rev. ST Accel. Beams 9, 060701 (2006).

 
WEPMA111 Mechanical Engineering Challenges in the Development of the FEL at RRCAT 479
 
  • S. Chouksey, S. Krishnagopal, V. Kumar, S. Lal, K. K. Pant, V. Prasad
    RRCAT, Indore (M. P.)
  
  The Compact Ultrafast TErahertz Free-Electron Laser (CUTE-FEL) is being developed by BP&FEL Laboratory, RRCAT, which is designed to lase around 80 mm. Sub-systems like S-band high gradient accelerating structures, pre-buncher, buncher, pure permanent undulator etc. have already been developed and others are in advanced stage of fabrication/commissioning. In this paper we present the design, fabrication, measurements and status of various prototype developments of structures.