NPL News

Dr. Thomas Rao successfully defends thesis

Congratulations to Dr. Thomas Rao who successfully defended his thesis on Tue. Apr. 23 before the committee of Jen-Chieh Peng (chair), Doug Beck (advisor), Gordon Baym and Russ Giannetta.  Dr. Rao’s thesis, entitled “Transport of 3He for the nEDM experiment at the SNS” described the results of an experiment to measure the diffusion constant of 3He in superfluid 4He.  The experiment was carried out at the Harvard laboratory of Ike Silvera, and with the assistance of our technical staff: John Blackburn, Peter Sobel, Eric Thorsland together with Jaakko Koivuniemi and Steve Williamson from NPL, Weijun Yao from ORNL, and James Maxwell from MIT (now JLab).
Author: Prof. Doug Beck
Published on 4/26/2019

New results on sea-quark asymmetry from SeaQuest


The Fermilab SeaQuest experiment, designed to measure the light sea-quark flavor structure covering the large Bjorken-x region (up to x=0.45), has completed data-taking in July, 2016. The up and down sea-quark distributions are measured using 120 GeV proton beam interacting with liquid hydrogen and deuterium targets. The new result from an analysis of roughly half of the SeaQuest data was just announced in the Deep-Inelastic-Scattering Conference (April 8-12) in Italy. Jason Dove, a UIUC graduate student, presented this new result on behalf of the SeaQuest Collaboration. His talk can be found at:
https://indico.cern.ch/event/749003/contributions/3344635/attachments/1826425/2989273/DIS_slides_v14.pdf
The current UIUC members of the SeaQuest Collaboration include Jason Dove, Hugo Leung, Naomi Makins, Shivangi Prasad, Andrew Chen, and Jen-Chieh Peng
Author: Professor Jen-Chieh Peng
Published on 4/18/2019

A new review article on "Physics with Reactor Neutrinos"

A review article dedicated to the subject of "Physics with Reactor Neutrino", coauthored by Xin Qian at BNL and Jen-Chieh Peng at UIUC, was recently published in 'Report of Progress in Physics'. This article presents the history and highlights of reactor neutrino experiments, including the Daya Bay Neutrino Oscillation experiment, of which UIUC has been a member since inception. The review article, published in Rep. Prog. Phys. 82, 036201 (2019), can be found at:
https://arxiv.org/pdf/1801.05386.pdf
Author: Professor Jen-Chieh Peng
Published on 4/18/2019

Lepton angular distributions in Drell-Yan and Z-boson production

Two recent articles aiming at providing new insights on the origins of the lepton angular distribution in the Drell-Yan and vector-boson production were published. In a series of four articles, the long-standing puzzle of the origins of the violation of the "Lam-Tung" relation in the Drell-Yan process was explained using an intuitive "geometric" picture. This approach is currently being extended to other high-energy hard-scattering processes. The two latest articles appear in Phys. Lett. B789, 356 (2019) and Phys. Rev. D99, 014032 (2019). They can be found at:
https://arxiv.org/pdf/1811.03256.pdf
https://arxiv.org/abs/1808.04398.pdf
These latest papers were co-authored by Wen-Chen Chang, Oleg Teryaev, Daniel Boer, Jen-Chieh Peng (UIUC), Evan McClellan (former UIUC student, now at Jefferson Lab).
Author: Professor Jen-Chieh Peng
Published on 4/18/2019

A collision of light

Professor Anne Sickles is currently teaching a laboratory class at the University of Illinois in which her students will measure what happens when two photons meet. What they will find is that the overlapping waves of light get brighter when two peaks align and dimmer when a peak meets a trough. She tells her students that this is process called interference, and that—unlike charged particles, which can merge, bond and interact—light waves can only add or subtract. “We teach undergraduates the classical theory,” Sickles says. “But there are situations where effects forbidden in the classical theory are allowed in the quantum theory.”
Author: Sarah Charley
Published on 4/16/2019

ACDIS Seminar

ACDIS Seminar Speaker:
Ageg Danagoulian, MIT

February 19, 2019
136 Loomis Laboratory
3:30 to 4:30pm

Nuclear disarmament treaties are not sufficient in and of themselves to neutral-ize the existential threat of nuclear weapons. Technologies are necessary for verifying the authenticity of the nuclear warheads undergoing dismantlement before counting them towards a treaty partner’s obligation.Using Monte Carlo simulations and experimental proof-of-concept measurements, these techniques are shown to reveal no isotopic or geometric information about the weapon, while readily detecting hoaxing attempts.The talk will discuss the concept and recent results, and will give a general overview of nuclear security research pursued at MIT.
Author: NPL News
Published on 2/12/2019

News from former & current NPL graduate students

Dr. En-Chuan Huang, who received his Ph.D from UIUC in 2016 on the Daya Bay Neutrino Oscillation Experiment, gave an invited talk at the Neutrino 2018 Conference announcing the observation of low-energy excess at a 4.8 standard deviation from his analysis of the MiniBooNE data. This result was one of the highlights at Neutrino 2018 Conference. En-Chuan was then invited to give a “Wine and Cheese” seminar at Fermilab in July 2018. This is the second time that he was invited to give the prestigious Fermilab “Wine and Cheese” seminar during a period of two years. The first one was on his Ph.D work on the Daya Bay experiment. En-Chuan is currently a postdoc at the Los Alamos National Laboratory. Dr. Pinghan Chu, who received his Ph.D from UIUC in 2012 on the “Dressed-Spin” effect for the neutron EDM experiment, was recently promoted to the position of Staff Member at the Los Alamos National Laboratory. Dr. Chu recently received the Los Alamos LDRD support for his new proposal to search for Axion, one of the leading candidates for the Dark Matter which remains to be discovered. Dr. Evan McCllelan, who received his Ph.D degree from UIUC in 2016 on the Fermilab SeaQuest experiment, recently gave an invited talk at the Photonuclear Gordon Research Conference reporting the latest results from the MARATHON experiment. He is currently a postdoc at the Jefferson Laboratory. Ms Shivangi Prasad, a current UIUC graduate student, also presented an invited talk at this Conference on the latest result from the SeaQuest experiment.
Author: Professor Jen-Chieh Peng
Published on 11/12/2018

Pioneer in calculations of few-to-many-body systems passes

Steven C. Pieper, a pioneer in calculations of few-to-many-body systems, passed away last week.  Dr. Pieper received his Ph.D. in nuclear theory from UIUC in 1970 after receiving his undergraduate degree from the University of Rochester.  After a post-doctoral fellowship at Case Western, he moved to Argonne where he worked for over 50 years.  In the early 1980s he began a collaboration with Vijay Pandharipande and Bob Wiringa—the Urbana-Argonne collaboration—undertaking nothing less than detailed, first principles structural calculations of the largest nuclei possible—now heading up into the oxygen region.  This required making advantageous use of the high performance computing resources available at Argonne and elsewhere, Dr. Pieper’s long-time forte, work that continues to this day.  Among many contributions, these calculations helped us to understand the neutron halo nuclei helium-6 and helium-8 and is currently being applied to calculate electromagnetic and weak interaction responses necessary to interpret measurements in the search for sterile neutrinos. Bob and Steve shared the 2010 APS DNP Bonner Memorial prize for this work.
Author: NPL News
Published on 10/16/2018

Early Accelerator Builders at the University of Illinois

The University of Illinois at Urbana-Champaign has had a distinguished record in developing accelerators for both nuclear/particle physics experiments as well as for the many applications thereof outside of subatomic physics per-se.  Donald Kerst built the world’s first betatron here in 1941, but, 5 years earlier Gerald Kruger and his students built the world’s third cyclotron and the first outside of Berkeley.  The Department’s historian, Celia Elliott, has put together a terrific article from the archives outlining these developments and the people who made them possible.
Author: Celia Elliott
Published on 9/6/2018

CCD, LSI and CC Funding Outlook

Last week the nEDM collaboration met in Washington with our review committee and representatives of the NSF and DOE to assess the status of our experiment following the “Critical Component Demonstration” (CCD) phase of development.  The next phases of the experiment will involve both building up the subsystems from the components we have prototyped in CCD, called “Large Subsystem Integration” (LSI), as well as procurement of the “Conventional Components” (CC), such as the experimental hall, the neutron beamline, the magnetic shield and the cryogenic plant, needed for the operation of the experiment.  We received a strong, positive response from the review committee with encouragement to try to complete the fabrication as soon as possible.  We have now been funded by both agencies for the coming years; in particular, NSF is putting the finishing touches on support of our helium-3 services subsystem (Illinois) and the magnetic systems (Caltech).  In total, NSF will provide $7.7M ($4.4M to Illinois) over the next 5 years to complete these two subsystems, including the magnetic shield.  The total NSF equipment support for these two subsystems, including CCD, LSI and CC totals over $13M, significantly in excess of the $11M we agreed on at the outset of the project.  We are very grateful to NSF for their increased contribution.  Congratulations to everyone in the collaboration, and, in particular, to everyone in Urbana who helped make this possible: grad students Tom Rao, Sarvagya Sharma and Blake Erickson together with numerous undergrads, technicians John Blackburn, Lucas Hsu, Peter Sobel and Eric Thorsland, and, of course, our subsystem manager, Steve Williamson.
Published on 8/20/2018