Total Loss Monitor Report All experimenters meeting 5/12/14 A. Leveling

5/12/2014 A. Leveling 2 TLM detector cable Chipmunk Chipmunk electrometer (blue box) Chipmunk ion chamber Prelude

5/12/2014 A. Leveling 3 3 parallel TLM detectors 125’ 250’ 350’ Pbar A2B7 magnet TLM provides continuous, in-tunnel coverage Chipmunks provide discrete, above-ground coverage Prelude

The problem:  Radiation Safety System (RSS) at pbar service buildings includes 42 Chipmunks  Adequate for the 8 GeV, 13 watt pbar ops  RSS needs to be extended for 8 GeV, 8 kW mu2e operation – about 200 units  Unit cost is about $10k or total of $2M  Includes detector construction, doghouses, electrical installation M&S, RSS infrastructure  Would add tremendous complexity, e.g.,  Chipmunks require annual calibration  RSS testing 5/12/2014 A. Leveling 4

Why TLMs?  Following a Director’s review in May 2011 for mu2e CD1, ESH&Q Section Head suggested that we consider Long Detectors in lieu of Chipmunks  Long detectors have a long history at FNAL; they have been highly regarded by their proponents  Switchyard  Booster  NuMI  External beam lines  The obstacle: long detectors could not serve in the capacity of a CREDITED CONTROL for the Accelerator Safety Envelope 5/12/2014 A. Leveling 5

Development history  Work to characterize long detector response began immediately in May 2011  A long series of studies was conducted at pbar to characterize detector response as a function of 8 GeV beam loss  Detector response curves for the ion chamber region were developed 5/12/2014 A. Leveling 6

Development history  BLM electrometers were used in early studies with disappointing results  A Chipmunk, sans ion chamber, was then used (aka blue box, electrometer)  Provided linear, predictable response  The blue box was already a critical component of the existing RSS!  Electrometer: collects and measures charge produced in the detector 5/12/2014 A. Leveling 7

TLM electrometer development  The job was simply to mimic the features of the existing Chipmunk  Provide a heartbeat function  Failsafe design  Key problem was to develop the required dynamic range, not just for mu2e but for all conceivable applications – Booster, MI, NuMI, etc.  A couple of new design features were created to eliminate lost data collected by the site wide Radiation Monitoring System (MUX) 5/12/2014 A. Leveling 8

TLM detector/electrometer testing  3 electrometers were designed  The chosen design has been in service in wide variety of applications starting in December 2012  Linac – 10 foot detector  Booster – 180 foot detector (P10-12)  Pbar – 125’, 250’, and 350’ detectors  NuMI – four 200’ connected in series  NML – 10 foot detector 5/12/2014 A. Leveling 9

How does it work?  The shielding thickness available at a given location, along with desired occupancy, determine upper limit of allowable beam loss  The TLM trip level is determined from our knowledge of detector response as a function of beam energy and intensity  Developed over the past 3 years with measurements 5/12/2014 A. Leveling 10

Progress over the past year  Electrometer module development and construction – completed end of April 2013  Prototype and detector testing - May 2013 to present  Documentation submitted to AD ES&H - October 2013  ES&H Section Approval - May 2014  Allows $2M risk for mu2e to be retired  Cost of TLM systems about $200k 5/12/2014 A. Leveling 11

What does preliminary approval mean?  We can build, install, AND connect systems to the RSS  First application is Booster  A system covering the entire ring will be installed later this year  A parallel section of detector already installed in Booster (P10-12) will be compared with its new companion for a period of 1 year  Assuming required documentation is submitted and testing period goes well, we could be expect FINAL APPROVAL in September /12/2014 A. Leveling 12

Other applications to be studied before final approval  NuMI beam line  Already under study since 9/2013  MI52, slow resonant extraction at MI  MI30 collimation section  ASTA  By the time TLMs are required for mu2e, their use will have been well established 5/12/2014 A. Leveling 13

Extra slides 5/12/2014 A. Leveling 14

5/12/2014 A. Leveling 15