NPL News Now

December 12, 2016
nEDM Annual Review

The neutron EDM experiment is currently in the third year of a four year “Critical Component Demonstration”. In this phase, we have been building some of the important internal parts for the experiment, such as the dilution refrigerator. We have our annual review coming up on Dec. 12 in Washington when a group of reviewers and agency representatives will assess progress. In addition to reviewing progress over the past year and plans for the next one, one of our main tasks has been to prepare a more detailed plan for the Large Scale Integration, Assembly and Commissioning and Data Taking phases of the experiment extending into 2021 and beyond. In the next stage, Large Scale Integration, which we hope to start in 2018, we will begin assembling the critical parts from the current stage, together with acquiring the big ticket items like the helium liquefier, the neutron beamline and magnetic shield house.

November 28, 2016
Prototype Calorimeters shipped to Brookhaven National Lab

Last week 16 prototype calorimeters were shipped to Brookhaven National Lab. They were built and machined at the NPL. At Brookhaven they will be outfitted with lightguides and electronics and then will be tested in a beam at Fermilab in January. These are prototypes for the sPHENIX Experiment which is a large new experiment being built at the Relativistic Heavy Ion Collider at Brookhaven. We look forward to taking data with these calorimeters soon.

November 10, 2016
CERN Finance Review Committee to meet for COMPASS collaboration

CERN, Geneva Switzerland. The Finance Review Committee, FRC, for the COMPASS collaboration at the Super Proton Synchrotron at CERN meet on November 10th. The committee approved an extension of the Memorandum of Understanding between COMPASS institutions and the host laboratory to December 31st, 2020. This will make it possible to extend COMPASS data taking into 2018 and COMPASS data analysis through the end of the decade. The FRC judged COMPASS finances to be sound. COMPASS co-spokesperson Dr. Oleg Denisov from the INFN in Turin, Italy, also presented the significant progress the collaboration has made in publishing results, in the acquisition of additional data samples and the completion of several instrumentation upgrade projects in COMPASS. (1) Two UIUC efforts were briefly discussed: Drift chamber DC5 has completed a front end electronics upgrade and operates reliably with good particle detection efficiencies. (2) An exploratory project on NCSCA's Blue Waters super computer has demonstrated that COMPASS raw data and Monte Carlo data analysis can be carried out on Blue Waters efficiently. Dr. Caroline Riedl, who has been the leader of the COMPASS computing effort on Blue Waters has submitted a large scale proposal to the Peta Scale Computing Program of the NSF.

November 7, 2016
nEDM Heat Flush Test at Harvard

In the nEDM experiment, we have to move 3He from one place to another during each measurement. To do this we create a “wind” of phonons (like sound waves) using a heater. The wind actually blows the 3He atoms from warmer to colder regions. In Ike Silvera’s lab at Harvard, we test the effect by measuring the increase in pressure due to the higher 3He concentration in the cold region. After seeing the effect for the first time in our last run in August, we are now trying to improve the signal-to-noise ratio and improve our understanding of the timescales for this “heat flush” effect.

November 2, 2016
4 K Section of Dilution Refrigerator Tested at NPL

The final components of the 4 K section of the nEDM dilution refrigerator were successfully cooled and leak-checked at NPL. The key component, a a 30 liter LHe reservoir was cooled to about 55 K using the cryocirculator, and then filled with LHe. The LHe from the reservoir was recovered using both our existing recovery system and a new, larger system that is being commissioned for the dilution refrigerator operation. The next stage of construction comprises the components in the 1 K region. Operation of the dilution refrigerator at 0.25 K is expected early in 2017.