Storage Rings Group Meeting

Steve Werkema24 March 2010

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Rings Group Web Page

Present location of our web page:http://www-bdnew.fnal.gov/pbar/organizationalchart/werkema/Mu2e.htm

• 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:475/1.02.01.01.02 (AD-Mu2e-Accelerator and Beamline-Conceptual

Design)

24 March 2010

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Rings Group Organization

1.2.4 Storage Rings (Steve Werkema)1.2.4.1 Storage Rings R&D (Werkema/Nagaslaev)

1.2.4.1.1 Momentum Stacking R&D (Peterson/Bhat/Werkema)1.2.4.1.2 Bunch formation R&D (Peterson/Bhat/Werkema)1.2.4.1.3 Injection / extraction kicker R&D (Dave VanderMeulen)1.2.4.1.4 Space charge studies (Steve Werkema)1.2.4.1.5 Coherent instabilities1.2.4.1.6 Lattice adjustments1.2.4.1.7 Accumulator / Recycler energy match1.2.4.1.8 Beam studies

1.2.4.2 Beam lines (Jim Morgan)1.2.4.3 RF Systems (Dave Peterson)1.2.4.4 Instrumentation (Dave Peterson)1.2.4.5 Cooling removal(Brian Drendel)1.2.4.6 Beam Damper systems (Dave Peterson)1.2.4.7 Beam abort system (Jim Morgan)1.2.4.8 Infrastructure improvements (Brian Drendel)24 March 2010

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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 2010

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A-D Line (Morgan)

24 March 2010

This arrangement probably won’t work.

Need now: Identify ‘reasonable’ A-D line layouts.

Constraints:• kicker – septa: Dmx = nodd*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 Dp > 100 MeV/c)

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Kickers (VanderMeulen)

• Accumulator injection– 15 Hz operation– Flattop 80 53 MHz buckets– 2 bucket fall time

• 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– Same rep-rate as

Accumulator extraction kicker– 400 ns < flattop < 1.7 ms

24 March 2010

38 ns 38 ns

1.5 ms

67 ms

20 ns 20 ns

360 ns

150 ms

38 ns 38 ns

1.7 ms

150 ms

Not to scale

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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 NOnA kickers for our purposes

3. Begin thinking about abort requirements (Jim Morgan)

4. Begin a Mu2e kicker collaboration with Tech. Div.24 March 2010

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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– Zeroth order concept of the low level systems

24 March 2010

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Debuncher Resonance Mapping Study (Werkema/Drendel)

Vary nx 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 Dp blowup on injection orbit for protons

24 March 2010

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Debuncher Resonance Mapping Study (Werkema/Drendel)

24 March 2010

Problems:

1. gt changes by ~4% (h by 22%) during scan

2. Horizontal bmax gets big as the ½ integer is approached

DIQF DIQDn1 n2 gt

b1max b2max h(Amp) (Amp) (m) (m)

0.00 0.00 9.7692 9.7747 7.6800 23.58 21.02 0.0059-0.50 -0.17 9.7483 9.7747 7.6553 23.53 21.03 0.0060-1.00 -0.34 9.7274 9.7747 7.6305 23.65 21.04 0.0061-1.50 -0.51 9.7065 9.7747 7.6057 23.88 21.05 0.0063-2.00 -0.67 9.6857 9.7747 7.5806 24.20 21.06 0.0064-2.50 -0.84 9.6649 9.7747 7.5556 24.57 21.07 0.0065-3.00 -1.01 9.6442 9.7747 7.5305 25.03 21.09 0.0066-3.50 -1.18 9.6235 9.7747 7.5054 25.61 21.10 0.0067-4.00 -1.35 9.6029 9.7747 7.4801 26.39 21.11 0.0068-4.50 -1.52 9.5823 9.7747 7.4547 27.55 21.12 0.0070-5.00 -1.69 9.5618 9.7747 7.4292 29.54 21.13 0.0071-5.50 -1.86 9.5413 9.7747 7.4036 34.12 21.14 0.0072

ny

nx

IQD

gt

bymax

bxmax

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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 – PenthouseAgenda: Progress reports

24 March 2010