We examine the use of sextupole magnets to correct nonlinearities in the longitudinal phase space transformation of a relativistic beam of charged particles in a dispersionless translating section, or dogleg. Through heuristic analytical arguments and examples derived from recent experimental endeavors, and augmented by simulations using the particle tracking codes PARMELA and ELEGANT, sextupol...

A proof of principle experiment is underway at the UCLA Neptune laboratory to test the concept of generating linearly ramped relativistic electron bunches (rising in density from head to tail followed by a sharp cutoff) by using a sextupole-corrected dogleg section as a bunch compressor. Bunches with this structure have been predicted to be ideal for use as a plasma wakefield drive beam. The di...

A ramped electron bunch (i.e. one having a current density which rises linearly from the head to the tail and then drops sharply to zero) has been predicted to be an ideal drive beam for the plasma wake field accelerator due to the large transformer ratio it is capable of generating. A scheme was recently proposed for the creation of a relativistic electron bunch that approximates a ramped curr...

The least squares adjustment (LSA) method is studied as an optimisation problem and shown to be equivalent to the undamped Gauss-Newton (GN) optimisation method. Three problem-independent damping modifications of the GN method are presented: the line-search method of Armijo (GNA); the LevenbergMarquardt algorithm (LM); and Levenberg-Marquardt with Powell dogleg (LMP). Furthermore, an additional...

1098-4402= We examine the use of sextupole magnets to correct nonlinearities in the longitudinal phase space transformation of a relativistic beam of charged particles in a dispersionless translating section, or dogleg. Through heuristic analytical arguments and examples derived from recent experimental efforts, augmented by simulations using the particle tracking codes PARMELA and ELEGANT, sex...

The MIT Faculty has made this article openly available. Please share how this access benefits you. Your story matters. Full exploitation of emittance exchange (EEX) requires aberration-free performance of a complex imaging system including active radio-frequency (rf) elements which can add temporal distortions. We investigate the performance of an EEX line where the exchange occurs between two ...

Each Location Directory (LD) provides the information to locate the forwarding address of aMobile Host (MH) in a mobile networking system. The LD should be updated when the MH moves from one access zone to another access zone. If an Internet Access Point (IAP) (or base station) could cache some useful LD information entries, then, after receiving a packet from an MH in its access zone, the IAP ...

introduction: more than 50 scoring systems have been published for classification of trauma patients in the field, emergency room, and intensive care settings, so far. the present study aimed to compare the ability of trauma injury severity score (triss) and acute physiology and chronic health evaluation (apache) iii in predicting mortality of intensive care unit (icu) admitted trauma patients....

in schizophrenia, neurocognitive functions are one to two standard deviations below the normal controls and these deficits have a significant relationship with overall functioning and poor outcome. according to this fact, it is important to investigate the factors that effect neurocognition in schizophrenic patients. this study was carried out to demonstrate the relationship between attention/v...