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Modular cavity status and test Modular cavity status and test plan plan Daniel Bowring Overview Daniel Bowring RF Measurements Experimental Plan Fermi National Accelerator Facility Photos May 30, 2014 Overview Modular cavity status and

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Modular cavity status and test plan Daniel Bowring Overview RF Measurements Experimental Plan Photos

Modular cavity status and test plan

Daniel Bowring

Fermi National Accelerator Facility

May 30, 2014

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Modular cavity status and test plan Daniel Bowring Overview RF Measurements Experimental Plan Photos

Overview

1. Frequency and Q have

been verified.

2. The cavity has not been

delivered to FNAL yet. Endplate flanges are mechanically weak, making the RF joint unstable.

3. We believe this is a

solved problem.

4. Meanwhile, what is the

experimental plan? (Plus: photos.)

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Modular cavity status and test plan Daniel Bowring Overview RF Measurements Experimental Plan Photos

RF Measurements

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Modular cavity status and test plan Daniel Bowring Overview RF Measurements Experimental Plan Photos

We have verified the RF properties of the cavity.

(Quantitative data on next slide.)

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Modular cavity status and test plan Daniel Bowring Overview RF Measurements Experimental Plan Photos

RF design vs. measurement

Property Sim. Meas. Notes Frequency (MHz) 804.99 804.65 Measurement w/o vacuum Unloaded Q0 25602 24383 Loaded QL 11861 15141 Not under- stood. Bad RF adapter?

3040 50 60 7080 90 804.30 804.35 804.40 804.45 804.50 804.55 804.60 804.65 804.70 Frequency (MHz) 3040 50 60 7080 90 Torque (inch-pounds) 16000 18000 20000 22000 24000 Q0 3040 50 60 7080 90 0.6 0.7 0.8 0.9 1.0 1.1 beta

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Modular cavity status and test plan Daniel Bowring Overview RF Measurements Experimental Plan Photos

The recovery/shipping plan has now been vetted.

◮ Full design analysis and recovery discussion took place

yesterday evening: https://indico.fnal.gov/contributionDisplay. py?sessionId=16&contribId=133&confId=8326

◮ Minimally invasive plan gets the cavity to FNAL ASAP. ◮ Staged “upgrades” possible if the minimally invasive fix

proves insufficient.

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Modular cavity status and test plan Daniel Bowring Overview RF Measurements Experimental Plan Photos

Experimental Plan

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Modular cavity status and test plan Daniel Bowring Overview RF Measurements Experimental Plan Photos

Experimental goals of the modular cavity program

The modular cavity allows us to collect “clean” data.

◮ Mimics coupling strategy

in a cooling channel.

◮ Strongest surface E-field

(by 5×) is on-axis.

We can test different materials and surface treatments.

◮ Beryllium vs. copper ◮ Half-hard vs.

fully-annealed Cu

◮ Chemical polishing vs.

electropolishing

◮ Other materials?

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Modular cavity status and test plan Daniel Bowring Overview RF Measurements Experimental Plan Photos

Using the modular cavity

Sequence of runs

1. Chemically-polished Cu

plates, B=3/0

2. Chemically-polished Cu

plates, B=0/3

3. Beryllium plates,

B=TBD

4. Fully-annealed Cu plates
5. “Other” (15 cm body, Cu

alloy plates, etc.)

What does a single run look like?

i. Inspection
ii. Conditioning
iii. Inspection
iv. Establish safe operating

gradient

v. Inspection

Notation: B=3/0 denotes a run at 3 T followed by a run at 0 T.

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Modular cavity status and test plan Daniel Bowring Overview RF Measurements Experimental Plan Photos

Frequent inspection help us understand when damage occurs.

ASC: High-res scanner ASC: Digital microscope

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Modular cavity status and test plan Daniel Bowring Overview RF Measurements Experimental Plan Photos

Photos

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Modular cavity status and test plan Daniel Bowring Overview RF Measurements Experimental Plan Photos

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Modular cavity status and test plan Daniel Bowring Overview RF Measurements Experimental Plan Photos

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Modular cavity status and test plan Daniel Bowring Overview RF Measurements Experimental Plan Photos

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Modular cavity status and test plan Daniel Bowring Overview RF Measurements Experimental Plan Photos

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Modular cavity status and test plan Daniel Bowring Overview RF Measurements Experimental Plan Photos

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Modular cavity status and test plan Daniel Bowring Overview RF Measurements Experimental Plan Photos