Radiation is neither good nor bad. All types of radiation can be useful for some purpose, but many can be harmful in overdose conditions.
Assuming you mean the Large Hadron Collider - and lise in a circular tunnel beneath the Swiss/French border.
A Z-boson is a fundamental particle, a gauge boson, which, together with the W-boson, mediates the weak nuclear force, and has a charge of 0.
An antiquark is an antiparticle of a quark.
Yes, neutrons are bigger than quarks; it takes three quarks to make a neutron, and the whole is larger than the components. Based on the current understanding of the force between the quarks, we also have an idea of how far apart they are within the neutron.
Particle collision usually refers to two subatomic particles slamming into each other at high speeds causing them to break into smaller particles. These speeds are created by particle accelerators.
Weak interactions are interactions between subatomic particles that are mediated by the weak nuclear force. The first such interaction discovered was Beta Decay in radioactivity, where a neutron decayed into a proton, an electron, and a neutrino. The weak force is mediated by the W+, W-, and Z intermediate vector bosons being transferred between quarks.
Using electric fields. But velocity is increased step by step. In case of linear accelerator successive alternating right polarity accelerates to a higher uniform speed and it travels through proportionate lengthy tunnels. In case of cyclotron both electric (alternating) and intense magnetic field are used to increase the speed step by step.