Charge for WG2 (Optics and Beams) Georg H. Hoffstaetter (Cornell University / Physics) on behalf of the conveners of WG2: Vladimir Litvinenko (BNL / Accelerator Physics) Hywel Owen (Daresbury / ASTeC) Statistics: 10:00 / 11:00 talk time / discussion time (without coffee breaks) 29 speakers (40 registered participants) 1. Goal 2. Areas of Interest 3. Organization 4. Projects and Topics 5. Responsibilities 6. Vision of Results 7. Solicitation
Charge
Goals Overview of ongoing projects Overview of methods and techniques Overview of essential topics and limiting effects List of unsolved topics (are they addressed or not?) Prioritize unsolved topics Find synergy between projects Focus on most essential topics Exchange of ideas and software Collaborations on designs Collaborations on experiments Collaborations on computations Collaborations on software packages Production of a report on optics issues (?)
Goals for what subjects? Linear Optics Nonlinear Optics Bunch Compression / Decompression Emittance Control Transport of magnetized beam CSR effects Transverse and longitudinal beam stability Beam Breakup (BBU) Ion clearing / Ion gaps Front to end simulations Diagnostics requirements
Presented ERL projects JLAB-FEL JAERI-FEL RECUPERATOR FEL ERLplus Cornell Prototype Cornell X-Ray ERL 4GLS APS-ERL Arc en Ciel ecool-rhic erhic-erl ELIC
Session on Projects (Sunday)
Search for Synergies Similar design issues Similar parameter space Similar technical solutions Similar beam experiments required Collaborations on optics and beam transport on optics designs on experiments on computations and simulations on software packages
5GeV ERL Upgrade for CESR 6 5 8 7 1 4 2 3
Example of collaboration possibilities Full average current injector with the specified emittance and bunch length Emittance preservation during acceleration and beam transport: Nonlinear optics (code validation at CEBAF), coherent synchrotron radiation (TTF), space charge, modeling (4GLS) Delivery of short duration (ca. 100 fs, and less in simulations), high charge bunches (TTF) Dependence of emittance on bunch charge Stable RF control of injector cryomodule at high beam power Stable RF control of main linac cavities at high external Q, high current, and no net beam loading (JLAB to 10mA) Understanding of how high the main linac external Q can be pushed (JLAB) Study of microphonic control using piezo tuners (JLAB, SNS, NSCL, TTF) Recirculating beam stability as a function of beam current with real HOMs, and benchmarking the Cornell code BI (JLAB) Feedback stabilization of beam orbit at the level necessary to utilize a high brightness ERL Photocathode operational lifetime supporting effective ERL operation Performance of high power RF couplers for injector cryomodule Demonstration of non-intercepting beam size and bunch length diagnostics with high average current at injector energy and at high energy (TTF) HOM extraction and damping per design in injector and main linac (code validation from Cornell Prototype) Performance of HOM load materials to very high frequency Performance of full power beam dump Detailed comparison of modeled and measured injector performance Study of halo generation and control in a high average current accelerator at low energy and with energy recovery (JLAB) Study of beam losses and their reduction in recirculation of high average current with energy recovery (JLAB, NAA) Precision path length measurement and stabilization (Cornell Prototype, JLAB)
Optics issues for ongoing ERL projects Schedule Accelerator modeling Stability issues Merger design (with WG2) BBU and cavity optics Computational aspects Sunday Monday Tuesday Wednesday
Accelerator modeling (Sunday)
Stability issues (Monday)
Merger design (Monday)
BBU and cavity optics (Tuesday)
Computational aspects (Tuesday)
Nota bene on Instrumentation Issues for discussions on diagnostic necessities: a) Number and location of BPMs b) BPMs for two beams c) Number and location of beam size measurements d) Longitudinal beam profile measurements e) Longitudinal tomography f) Optic measurement procedures g) Beam based alignment procedures h) Commissioning strategies i) Emittance control j) Phase space tomography
Hopeful Conclusion 1) Survey of present status of ERL optics and beam transport. 2) List of unsolved problems. 3) Identification of physics and technology limits 4) What has been and what needs to be addressed 5) What are high priority research topics 6) Schedule for key developments 7) Initiation of collaborative effort 8) Talks should be short and leave much room for discussion