BNL, Upton, Long Island, New York, USA
In the 2013 RHIC polarized proton run, it was found that the RHIC bunch intensity has reached a limit due to the head-on beam-beam interaction at 2x1011, as expected by simulations. To overcome this limitation, two electron lenses will be used for compensation. We report on the commissioning of new lattices that reduce beam-beam driven resonance driving terms, and bunch-by-bunch proton diagnostic during 2013 run. The effect of electron beam transport solenoids on the proton orbit was tested. The instrumentation for Blue electron lens was tested and electron beam was propagated from the gun to the collector. A timing system was implemented for the electron beam. Control software, machine protection and synoptic display were developed and tested during commissioning. Both Blue and Yellow electron lens superconducting magnets are installed and their field straightness was measured and corrected in the tunnel using a magnetic needle. The Yellow vacuum system and backscattered electron detectors installation are also completed now.
BNL, Upton, Long Island, New York, USA
To commission some of the hard and software for the RHIC electron lenses (e-lenses), a test bench was built based on the EBIS test stand at BNL. After several months of operation, the electron gun, collector, high-voltage gun modulator, instrumentation, partial control system, and several software applications have been tested. The nominal DC beam current of 0.85 A was demonstrated and the electron beam transverse profiles were verified to be Gaussian. Some e-lens power supplies and the electronics for current measurement were also evaluated on the test bench. The properties of the cathode and the profile of the beam are measured. In this paper, we will present some experimental results.
BNL, Upton, Long Island, New York, USA
A new superconducting solenoid magnet was installed in the yellow ring of RHIC before Run 13 as part of the e-lens project. The second solenoid superconducting magnet will be installed in RHIC after Run 13 is over. There are 6 power supplies required for the solenoid, fringe and anti-fringe coils for both magnets. Commercial off the shelf unipolar power supplies are used to power the solenoid, fringe and anti-fringe coils. There are 24 corrector power supplies required for both magnets. Custom built 50A bipolar power supplies are used to power the correctors. Quench protection and quench detection have also been installed in this power supply system. In addition, 4 new phase shift power supplies have been installed in RHIC which are needed for the new e-lens system. These phase shift power supplies have been installed across the yellow focusing and defocusing arcs as well as the blue focusing and defocusing arcs from sector 8 to sector 10. Power Supply technology, control system, connections, the quench detection/protection system, and status will be presented.