2017-04-13-emittance¶

Thursday 13th April at 17:00 BST in MICE meeting room

Phone details¶

http://mice.iit.edu/phonebridge.html

Agenda¶

• Beam selection and emittance reduction - Chris Hunt
• Phase space density analysis using NN methods/etc - Francois Drielsma 20170413phase_space_volume.pdf
• Phase space density analysis using KDE method - Tanaz Mohayai
• Open issues in the data; summary of jobs; plan for IPAC and beyond - Chris Rogers
  • 2017-04-13_emittance-reduction-status.pdf
  • video - momentum evolution along the beamline, by particle species (red - pion; blue - muon; green - electron; black - sum)
• AOB

Notes¶

Present:

• Ken Long
• Pavel Snopok
• Tanaz Mohayai
• Dave Neuffer
• Ao Liu
• Chris Hunt
• Francois Drielsma

Chris Hunt

• looking at data; taking input beam at upstream tracker; studying how it behaves going through to the downstream tracker; is there a beam that behaves nicely and is cooled.
• can't use natural beam; effects of diffuser etc are present
• dug through some selection procedures
  • selection based on amplitude - chi2 distribution - only in upstream tracker; never found a beam that cooled with good transmission
  • 4D selection routine by looking at 2D projections; but pulled by parent distribution + sensitive to emittance
  • Issue with discrepancy between MC efficiency and data efficiency; why?
  • Tracking reconstructed beam back through the detector; re-reconstruction agrees but transmission does not agree
  • Trying to fix this analysis; covariance matrix corrections

Francois

• See slides
• Agree amplitude analysis for IPAC/rapid communication

Tanaz

• Systematic studies done previously
• Now looking into analysis using data
• Seeks to understand effects of different cuts, considering effect of cut on downstream data
• Observe larger cooling when include the scraping muons in the upstream sample than when we don't include the scraping muons; not well understood
• Cuts analogous to Rogers
• The KDE is sensitive to sample size; discussed an amplitude cut upstream to help

Rogers

• Didn't go through slides - but left as a reference
• Note that the analysis is advanced; progressing towards estimation of systematic bias
• Note as others have mentioned that the MC has incorrect aperture model

In discussion:

• Note there is a common set of data
• KL requires there is a common set of event selections so that we can begin to understand the systematics associated with the event selection; focus things on MC that cause discrepancies

Require:

• Good batch MC for 1.2
• Reconstruction with 2.8.4