A Computationally Efficient Two-Dimensional Model of the Beam–Wave Interaction in a Coupled-Cavity TWT

Validation study for the large-signal code TESLA-CC based on experimental Ka-band Coupled-Cavity TWT

“…The results presented on Fig.1 show that once adjusted, the same value for the beam-voltage Vb=16.23 kV used in TESLA-CC simulations allows to reach good agreement between the predicted and measured frequency band in both, smallsignal and large-signal regimes of the device's operation. As expected, 2D code can provide better agreement with the experiment, than the 1D code does [2,3]. Another important result of the current study is the finding in simulations much bigger, than expected, role of the additional drift tube presented inside the sever section of the experimental CCTWT.…”

“…In a few recent years a series of Ka-band coupled-cavity TWTs have been successfully developed, built and tested at CPI [1] in collaboration with the NRL and SAIC. This activity gave impulse to the new code development in NRL [2,3] to provide computational tools capable on a more efficient and more accurate modeling of the CCTWTs, including the wide improvement and optimization in their output parameters and overall efficiency.…”

“…The generally used in these devices non-uniform PPM focusing magnetic field makes it largely important to take into account effects of the 2D dynamics of the beam, what requires fully 2D simulations for more accurate modeling of such CCTWTs. To address this issue we have performed wide modeling of experimental CCTWTs by using the recently developed 2.5D code TESLA-CC [3]. For the purposes of the code's TESLA-CC validation, a very detailed study was completed for the so called NRL-1 tube [1].…”

Microfabrication and Cold Testing of Copper Circuits for a 50 Watt, 220 GHz Traveling Wave Tube

“…To mitigate the need for lengthy simulations in PIC-type codes and to accurately determine the performance of the asbuilt device, the 2.5D large signal NRL code TESLA-CC [12] was extended recently for modeling of TWTs with serpentine (SW) and folded waveguide (FW) circuits [13,14]. The dimensions of the fabricated SW structure have been measured with high precision and have been used as input data for simulations.…”

A three dimensional large signal model for sheet beam travelling wave tubes

“…Some large signal modelshad been built for the pencil beam TWTs, and the calculationresults were shown to compare favorablywith measurements [1][2][3][4].However, the beamwave interaction analysis for the SBTWTwasusually performed by time consuming 3D particle-in-cell (PIC)simulations. Thus an efficient simulation code ispresented for the SBTWTs in this abstract.Because the beam-wave interaction in the planer circuitis usually continuous, just as in the helix TWTs, sothe methodology adopted in the helix TWT codeCHRISTINE3D [1],has been extended to our model.The complete descriptionof the steady state large signal modelincludes the dynamic equation andthe equations of motion.…”