  In the study of relativistic jets one of the key open questions is their
interaction with the environment on the microscopic level. Here, we study the
initial evolution of both electron$-$proton ($e^{-}-p^{+}$) and
electron$-$positron ($e^{\pm}$) relativistic jets containing helical magnetic
fields, focusing on their interaction with an ambient plasma. We have performed
simulations of "global" jets containing helical magnetic fields in order to
examine how helical magnetic fields affect kinetic instabilities such as the
Weibel instability, the kinetic Kelvin-Helmholtz instability (kKHI) and the
Mushroom instability (MI). In our initial simulation study these kinetic
instabilities are suppressed and new types of instabilities can grow. In the
$e^{-}-p^{+}$ jet simulation a recollimation-like instability occurs and jet
electrons are strongly perturbed. In the $e^{\pm}$ jet simulation a
recollimation-like instability occurs at early times followed by a kinetic
instability and the general structure is similar to a simulation without
helical magnetic field. Simulations using much larger systems are required in
order to thoroughly follow the evolution of global jets containing helical
magnetic fields.
