Storage Rings Group Meeting Steve Werkema 24 March 2010

Rings Group Web Page Present location of our web page: Access to various Mu2e links. Storage for meeting minutes and slides. Place to put things of general interest to the group FTL Budget code for AD Mu2e work: 475/ ( AD-Mu2e-Accelerator and Beamline-Conceptual Design ) 24 March 20102

Rings Group Organization Storage Rings (Steve Werkema) Storage Rings R&D (Werkema/Nagaslaev) Momentum Stacking R&D (Peterson/Bhat/Werkema) Bunch formation R&D (Peterson/Bhat/Werkema) Injection / extraction kicker R&D(Dave VanderMeulen) Space charge studies(Steve Werkema) Coherent instabilities Lattice adjustments Accumulator / Recycler energy match Beam studies Beam lines(Jim Morgan) RF Systems(Dave Peterson) Instrumentation (Dave Peterson) Cooling removal(Brian Drendel) Beam Damper systems (Dave Peterson) Beam abort system (Jim Morgan) Infrastructure improvements (Brian Drendel) 24 March 20103

Agenda 1.Admin. 2.A-D Transfer Line – location options 3.Injection/Extraction kicker requirements 4.RF System Specification 5.Debuncher resonance stop band mapping study 6.Emasculated rings drawing 24 March 20104

A-D Line (Morgan) 24 March This arrangement probably won’t work. Need now: Need now: Identify ‘reasonable’ A-D line layouts. Constraints: kicker – septa:  x = n odd *90  room in Acc & Deb lattice for kickers and septa. Acc extr & Deb inj kickers at zero (small) dispersion (easier kicker design) beamline must not go through stairways or interior walls Avoid A30 straight section (injection and extraction) A-D line must have a large momentum aperture (FW  p > 100 MeV/c)

Kickers (VanderMeulen) Accumulator injection Accumulator injection – 15 Hz operation – Flattop  MHz buckets – 2 bucket fall time Accumulator extraction Accumulator extraction – 6 – 7 Hz operation (determined by spill duration) – Pick off one 2.5 MHz bunch at a time – 200 ns < Flattop < 397ns – Very fast rise and fall times Debuncher injection Debuncher injection – Same rep-rate as Accumulator extraction kicker – 400 ns < flattop < 1.7  s 24 March ns 1.5  s 67 ms 20 ns 360 ns 150 ms 38 ns 1.7  s 150 ms Not to scale

Kickers (VanderMeulen) Accumulator kickers won’t be shuttered  must specify acceptable stray field in vicinity of central orbit Also need two pulsed septa (Accumulator extraction and Debuncher injection) And while we’re at it, we’ll need one or two abort kickers. This is a matter of some urgency since proper dump shielding may require civil construction. What we need now: 1.Basic specification of each kicker 2.A consult with Chris Jensen as to the adaptability of the NO A kickers for our purposes 3.Begin thinking about abort requirements (Jim Morgan) 4.Begin a Mu2e kicker collaboration with Tech. Div. 24 March 20107

RF System (Peterson/Werkema) What we need now: Start with the Chandra Bhat ESME simulations (this week) – Add impedances, beam loading – Chandra at CERN for a year beginning in May Determine basic hardware requirements – How many cavities needed for each system – Power amplifier requirements – Zero th order concept of the low level systems 24 March 20108

Debuncher Resonance Mapping Study (Werkema/Drendel) Vary x between ~9.5 and ~9.8 (includes 1/2, 2/3, and 3/4 resonances) Determine which resonances are driven and their widths. 1.Stacking with 10 sec (or longer) cycle time. Longer cycle time gives better sensitivity. 2.Momentum cooling on for entire cycle. Transverse cooling gated off early to facilitate tune measurement. 3.Sit at each quad bus setting for several super-cycles. Measure the following: – Horizontal & vertical tunes – Measure (histogram) Debuncher beam intensity (D:BPI10D, D:BEAM, etc.) – Measure (histogram)  p yield at various places (A:PRDCTN, Z:PRDCTD) – Measure (histogram) integrated losses on loss monitors (create a global sum device). Need Now: Develop detailed study procedure Proof-of-principle study within next few weeks. Refine the procedure and try again. Start thinking about how to diagnose  p blowup on injection orbit for protons 24 March 20109

Debuncher Resonance Mapping Study (Werkema/Drendel) 24 March Problems:  t changes by ~4% (  by 22%) during scan 2.Horizontal  max gets big as the ½ integer is approached  IQF  IQD 1 2 tt  1max  2max  (Amp) (m) y x IQD tt  ymax  xmax

Rings drawing (Drendel) & etc. Brian Drendel + Wes Meuller working on a new rings drawing (sans cooling & and most of the RF) Will be posted on the web site and in Mu2e-doc database when complete Next Meeting: Wednesday, April 7, 2010, 10:00am – Penthouse Agenda: Progress reports 24 March