Accelerator Radiation Safety Newsletter


(all articles are to be considered personal/professional in nature and do not reflect the opinions of the institutions described unless otherwise stated)


An Official Publication of the

Health Physics Society's Accelerator Section

Circulation: 493

First Quarter 2016 /
Volume 26, Number 1



The President’s Message

Elaine Marshall


Accelerators are unique.  Someone once told me that when I was a relatively new accelerator health physicist. As I have reflected upon that comment, I realize just how unique each accelerator is.  The ones that I currently work with are much smaller and pulsed, firing just a couple of times per day.  The ones I used to work with were miles in circumference and ran continuously.  Shielding is different.  Occupancy is different.  Radiological hazards are different.  Industrial hazards are different.  The list can go on.


Interestingly, I find comfort in those differences and have come to realize that there are many similarities.  A majority of accelerator produced radionuclides are positron emitters.  The beam scatter is usually a greater problem.  Volumetric contamination is to be expected.  Contamination is generally predictable – dust, rust, residue.  Personnel protection is our utmost priority, but the machine is a close second.


During a recent teleconference of many within the DOE Accelerator Community, a speaker noted that we have to share our experiences to learn.  Our creativity is sparked by the ideas and application of theory belonging to others.   In this recent teleconference, one of the facilities discussed a problem they encountered with the administration of part of their interlock system/program.  Our program here is vastly different, but after wading through the details of the incident, I realized I had something to learn from this incident and reviewed our interlock program from this perspective.


With that in mind, I really would like to encourage those of you with one of those ideas or an alternate interpretation to present these at the upcoming HPS Annual Meeting.  My current manager often reminds me that the work that we do is worth discussing with our colleagues.  We don’t usually take the time because in our minds, we are just getting the job done. No one is interested in that.  However, I just sat in on a presentation utilizing room ventilation as a method for downposting.  As I think about that, that was a technique that I learned about decades ago.  Last year, we were reminded of monoenergetic electrons and their effect on our instrumentation.


The Accelerator Section has committed to hosting a special session at the HPS Annual Meeting.  Unfortunately, the submission date snuck up on most of us and passed us by.  Since it is a Special Session, the Accelerator Section has direct control over the presentations.   We have included a presentation on the application of the new accelerator clearance standard and Dr. Rokni has been invited to be one of the Plenary Session speakers.  We will have our outstanding student presentations.  We can still add presentations.  Please talk to Lorraine Day or contact me with any ideas that you might have.


BTW – Steve Frey has made great progress in scheduling a night under the stars for the Accelerator Section.   Look for it in the preliminary program.  He was telling me that there are a lot of similarities between accelerators and those beacons in the night.


The President-Elect’s Message

Lorraine Day (lightly added to by Steve Frey)


Is the Accelerator Section meeting your needs?

Times are a changing and as a consequence so must we.  The rapid confluence of scientific discovery and technological breakthroughs makes it more and more difficult to be on the cutting edge.  Why am I beginning this article with such a sentence?  It’s because that for our Section’s usual Special Session for the upcoming annual meeting in Spokane, fewer presentation papers than normal were submitted.


Now, we certainly will have the Special Session, and will make it interesting as always. It’s our duty to you, our Section members, to make our Special Sessions fun and informative, and that we will happily do.


Another of the very good things that our Section does is supporting deserving students, being the only HPS section to give society‑wide recognition through our prestigious modes of recognition awards: The H. Wade Patterson Award and the Lutz Moritz Award. With respect to this endeavor, we need judges for this annual event in Spokane. If you are willing to help in the pre-judging process where we cull every student abstract for this event, please let me know.


However, it too may be a good time to think of our mission on a larger scale, and re-evaluate our section mission and goals. This is a healthy process that all professional societies occasionally go through, and maybe we should, too.


First big challenge to think about: We are aware that our national laboratory members are constrained to only one meeting per year. Why is that conference not the HPS – and more specifically the Accelerator Section? What should we be doing to help more of you choose our meeting?


This is our way of saying that the Accelerator Section Board needs your help. We must improve our modus operandi; to meet the critical needs of our membership.  Therefore; I am requesting input, from you, our members. We need your suggestions; comments; recommendations and thoughts on how we can revitalize or “stem the tide”.  Each of you has a voice.  Now is the time to use it.  PLEASE send your confidential comments to me at  I plan to collate these comments and present them at both our board meeting and hopefully also during our Annual Business Meeting immediately following our short Special Session on Tuesday, July 19, 2016.


Again, please let me know your willingness to participate in the student abstracts.


I look forward to your comments and suggestions. Please help us serve you in every best way. 






The Past President’s Message

Steve Frey


Hello friends, as Spring approaches, it’s a good time to begin thinking about the upcoming annual HPS Meeting in Spokane. Thanks to our current Section officers, we are well-positioned to producing a top-level Special Session there for you to enjoy.  Please come!


As a reward for your membership in our Section, we’re going to have a star party there for your enjoyment as well! It will be a modest affair that will be held within easy walking distance from the Spokane Convention Center and the Davenport Grand Hotel, and will follow immediately after the Awards Banquet on Tuesday night, July 19, 2016, from 9 PM to 10:30 PM. Please plan to stop by and enjoy the wonders of the nighttime sky with us. After all, stars are particle accelerators, too!


And more wild things are happening in the world of physics. Let’s have a look:


Gravitational Waves: First and biggest of all is the recent, spectacular detection of gravitational waves by the Laser Interferometer Gravitational-Wave Observatory (LIGO). Equally as impressive, the involved researchers were able to quantitate these waves, which originated from a collision of two huge black holes in a faraway corner of the Universe 1.3 billion years ago!


This fantastic finding promises to have strong benefits for accelerator sciences, which we will explore further below.


Here’s a good video clip that tells how it was done: Brian Greene Explains The Discovery Of Gravitational Waves.


And here’s a visual simulation of the collision producing an intense gravitational wave (with a screen-capture from it below):


slack-imgs.com__1.jpeg (1200×591)


The researchers’ computer modelling of black hole collisions, when applied to the data (see LIGO Hanford and Livingston sites’ data graphs below; how’s that for a data match!), indicated that a 29-solar-mass black hole and a 36-solar-mass black hole merged. At the instant of collision, they converted 3 solar masses’ worth of material into gravitational waves. The power output of those waves was 50 times that of the entire visible universe! LIGO confirmed that gravitational waves are not only real, they can be substantial, too. Pretty impressive work!


The gravitational wave signals, as detected by the twin LIGO stations. Image Credit: LIGO


What does such a discovery mean for accelerator sciences? It confirms that Albert Einstein was even more correct about General Relativity than ever. Consequently, this latest validation of General Relativity suggests that accelerators can help advance particle physics with even greater confidence from better understanding and control over experimental influences due to gravity at the quark and sub-quark level.


Best of all, the LIGO success now opens a search pathway for accelerators to be the leading tool of choice to help find gravitons. Gravitons are thought to be tiniest particles in existence, being only a Planck-Length in magnitude (i.e., 1E-35 meters). These closed-string, 2-spin massless particles are thought to couple with the density and flux of energy and momentum in spacetime to produce the force-like entity known as gravity. If gravitons are discovered, they will meld Quantum Mechanics with General Relativity and validate the long-sought Grand Unification Theory (a/k/a "The Theory of Everything"), which is the holy grail of particle physics, astrophysics, and cosmology.


And we accelerator health physicists will be there to help. We do live in exciting times!


Quantum Entanglement. In what appears to be a coincidental dovetailing on LIGO beam-splitting technology, an experimental test for quantum entanglement has been devised. Quantum entanglement, or “spooky action at a distance” as Einstein described it, was proposed (facetiously) by Einstein to explain how a change in one particle could cause a complementary change to another particle to which it is linked faster than the speed of light. Einstein did not believe it to be possible. But recent laboratory efforts show it could be true. This new experiment will attempt to prove quantum entanglement visually, via beam‑splitters (much like LIGO uses to detect gravitational waves). Here’s a diagram from the experiment that shows how it will be designed:



If successful, the world of photon and particle physics will be absolutely rocked! Here’s the technical paper on the experiment: What does it take to see entanglement? It could also open up a whole new realm for accelerators to explore.


- Time tells tantalizing truths? Great breakthroughs in science can come from novel application of an existing technology to make great new discoveries. A current example is proposed to be carried out at the University of Reno to detect dark matter via careful analysis of ultra-minute variations in atomic clocks. Here’s the link to the related article: Atomic clocks and dark-matter signatures.


It‘s possible that nothing may come of it. But what an elegant concept in principle it is, and illustrates the power of creative thinking in making the most of tools at hand. So, stoke those synapses! The next awesome advancement in science could come from you.




Elaine Marshall,
Sandia National



Lorraine Day,
CAMD Louisiana State University


Past President:

Steve Frey,



Linnea Wahl,


Newsletter Editor:

Patrick Bragg,
Idaho National




Don Cossairt (2016), 
Fermi National

Accelerator Laboratory


Reginald Ronningen (2016), National Superconducting Cyclotron Laboratory


Matt Quinn (2018)
Fermi National Accelerator Laboratory

•  Accelerator Section Website

•  HPS Website

From The Secretary/Treasurer:
Linnea Wahl

The Health Physics Society’s (HPS) midyear meeting is behind us, and you may be wondering what financial news the Accelerator Section reported to the HPS Board of Directors at that meeting. All good news is the answer.


As of 1 January 2016, the section had a total of 196 members. With dues of $5 per member, the section earns $980 each year. After various expenses (primarily to support awards given to student presentations at each annual HPS meeting), as of 30 November 2015, the section had $9,655 in its coffers.


Good news indeed, but it could always be better. If you know of a colleague who should be a member of the HPS Accelerator Section but isn’t, please encourage him or her to join us. It’s easy—see “How to Join” at the bottom of the section’s website at


From Board Director Reginald Ronningen:



The Facility for Rare Isotope Beams (FRIB) at Michigan State University has an informative website that is public-friendly and a source for potential professional opportunities in accelerator science and safety. The website URL is




Charles W. Schaefer

Brookhaven National Laboratory


CeC-PoP Experiment at RHIC

Accelerated ion beams in the Relativistic Heavy Ion Collider (RHIC) rings “heat up”.  As the particles that make up the beams move around and scatter off of one another, some speed up while others slow down, leading to a wide spread in their velocities.  This spreading of velocities heats and enlarges the beam, which creates a challenge for physicists trying to get the particles to collide at the STAR and PHENIX intersecting regions. Physicists at the RHIC are exploring ways to cool the beams and keep their particles tightly packed.  Keeping the beams tightly packed increases luminosity and collision rates at intersecting regions, which produces physics data at faster rates.

The goal of the Coherent Electron Cooling Proof of Principle (CeC-PoP) experiment is to demonstrate beam cooling in the longitudinal energy spread of the RHIC beam.  The process will reduce the hadron beam energy spread, i.e., beam cooling is expected to increase beam particle density and increase the collision rate of accelerated ions at intersecting regions and, hence, produce more scientific data more quickly.  The scope of the experiment is to cool a single bunch of 40 GeV/u Au ions.  In addition to use of electron beam for CeC experiment, the electron beam will be used to study novel aspects of beam-beam effects in RHIC by collisions between the electron and hadron beams.

The CeC-PoP accelerator is housed inside the RHIC tunnel at the 2 o’clock sector.  It consists of a super-conducting RF gun with photocathode, beam bunchers, super-conducting RF cavity for beam acceleration, beam transport elements, FEL wiggler and beam dump.  A 22 MeV electron beam will be merged with 6 to 12 Au ion bunches circulating in the Yellow Ring.  The maximum electron beam power is 8.5 kW.  Both beams will co-propagate through a 14-m long section of beam pipe after which the electron beam will be separated from the Yellow Au beam and dumped.

The CeC-PoP experiment meets the DOE definition of an accelerator; hence, it will be an “accelerator within an accelerator” and will take advantage of existing RHIC shielding and access controls for radiation protection and ODH.  The safety analysis has been completed, and the RHIC Accelerator Safety Envelope (ASE) has been modified and approved to include those credited controls that are specific to the experiment, for example, limiting the electron beam energy to 25 MeV, supplemental shielding in place and configuration controlled, etc.

An Accelerator Readiness Review (ARR) for full power commissioning was completed in early March 2016, and the goal is to run the experiment during the CY2016 RHIC run.  It is expected that CeC-PoP will run for several years and provide significant input towards the design of a high-energy electron-ion collider.


Subscribe or Update Your E-mail Address

If you wish to contact the editor of this newsletter click here