The Ann Arbor Workshop on Increasing the AGS Polarization discusses the surprising spin effects discovered at lower energy accelerators, making the new multi-hundred-GeV RHIC polarized proton collider especially important. The four Siberian snakes in the two RHIC rings successfully preserved most polarization during acceleration and storage; RHIC's main problem was the low polarization injected from the AGS. The Workshop determined a quick and practical plan for increasing the AGS polarization by using three techniques to overcome the three types of depolarizing resonances.

This workshop's focus is on considering ways for improving the proton beam polarization that the AGS delivers to the RHIC. This talk attempts to review the first decade of AGS polarization--the 1980's; to briefly describe some aspects of the machine situation, the depolarization avoidance strategies employed and the success achieved in AGS from the perspective of one of those involved.

Updated analysis of how the increasing polarization of American politics has been accompanied and accelerated by greater income inequality. The idea of America as politically polarized—that there is an unbridgeable divide between right and left, red and blue states—has become a cliché. What commentators miss, however, is that increasing polarization has been closely accompanied by fundamental social and economic changes—most notably, a parallel rise in income inequality. In this second edition of Polarized America, Nolan McCarty, Keith Poole, and Howard Rosenthal use the latest data to examine the relationships of polarization, wealth disparity, immigration, and other forces. They find that inequality feeds directly into political polarization, and polarization in turn creates policies that further increase inequality. Paul Krugman called the first edition of Polarized America “Important.... Essential reading for anyone who wants to understand what's happening to America.” The second edition has been thoroughly brought up to date. All statistical analyses, tables, and figures have been updated with data that run through 2012 or 2014, and the text has been revised to reflect the latest evidence. The chapter on campaign finance has been completely rewritten (with Adam Bonica as coauthor); the analysis shows that with so much “soft” money coming from very wealthy ideological extremists, there is even greater campaign contribution inequality than income inequality.

The AGS provides a polarized proton beam to RHIC. The beam is accelerated in the AGS from G[gamma]= 4.5 to G[gamma] = 45.5 and the polarization transmission is critical to the RHIC spin program. In the recent years, various systems were implemented to improve the AGS polarization transmission. These upgrades include the double partial snakes configuration and the tune jumps system. However, 100% polarization transmission through the AGS acceleration cycle is not yet reached. The current efficiency of the polarization transmission is estimated to be around 85% in typical running conditions. Understanding the sources of depolarization in the AGS is critical to improve the AGS polarized proton performances. The complexity of beam and spin dynamics, which is in part due to the specialized Siberian snake magnets, drove a strong interest for original methods of simulations. For that, the Zgoubi code, capable of direct particle and spin tracking through field maps, was here used to model the AGS. A model of the AGS using the Zgoubi code was developed and interfaced with the current system through a simple command: the AgsFromSnapRampCmd. Interfacing with the machine control system allows for fast modelization using actual machine parameters. Those developments allowed the model to realistically reproduce the optics of the AGS along the acceleration ramp. Additional developments on the Zgoubi code, as well as on post-processing and pre-processing tools, granted long term multiturn beam tracking capabilities: the tracking of realistic beams along the complete AGS acceleration cycle. Beam multiturn tracking simulations in the AGS, using realistic beam and machine parameters, provided a unique insight into the mechanisms behind the evolution of the beam emittance and polarization during the acceleration cycle. Post-processing softwares were developed to allow the representation of the relevant quantities from the Zgoubi simulations data. The Zgoubi simulations proved particularly useful to better understand the polarization losses through horizontal intrinsic spin resonances The Zgoubi model as well as the tools developed were also used for some direct applications. For instance, some beam experiment simulations allowed an accurate estimation of the expected polarization gains from machine changes. In particular, the simulations that involved involved the tune jumps system provided an accurate estimation of polarization gains and the optimum settings that would improve the performance of the AGS.

This volume assembles several top analysts of American politics to focus on solutions to polarization.

American Gridlock is a comprehensive analysis of polarization encompassing national and state politics, voters, elites, activists, the media, and the three branches of government.

The unexpected importance of high energy spin effects and the success of the ZGS in correcting many intrinsic and imperfection depolarizing resonances led us to attempt to accelerate polarized protons in the AGS. A collaborative effort is underway by the groups in Argonne, Michigan, Rice, Yale and Brookhaven to improve and modify the AGS to accelerate polarized protons. With the appropriate funding the first polarized proton acceleration at the AGS should be possible by 1983.

The AGS polarized H− source is now operational. During a month-long experimental physics run in July 1984, pulses equivalent to 15 .mu. A x 300 .mu.s (approx. 3 x 101° protons) were injected into the RFQ preaccelerator. Beam polarization, measured at 200 MeV, was approx. 75%. After the run, a program to increase the H− yield of the source was begun and significant progress has been made. The H− current is now frequently 20 to 30 .mu. A.A description of the source and some details of our operating experience are given. We also briefly describe the improvement program.

The past 100 years of accelerator-based research have led the field from first insights into the structure of atoms to the development and confirmation of the Standard Model of physics. Accelerators have been a key tool in developing our understanding of the elementary particles and the forces that govern their interactions. This book describes the past 100 years of accelerator development with a special focus on the technological advancements in the field, the connection of the various accelerator projects to key developments and discoveries in the Standard Model, how accelerator technologies open the door to other applications in medicine and industry, and finally presents an outlook of future accelerator projects for the coming decades.