Summer 2016 News
Beyond the palpable advantages to engaging in research of any kind as an undergraduate, there is one which I feel is slightly particular to our group here at CAMD. It goes beyond the level of inclusion extended to us by our mentors, who involve us within the ambit of our capabilities in the realisation of their plans, offering us experience and insight into the process beyond that afforded to many of my peers at this stage in the academic ontogeny. It is the duality of being entrusted at different stages to wrench, wire, collect and analyze, while still retaining the amnesty afforded to any undergrad from much of the emotional burden when things go wrong.
Thus, when Week 5 opens to trouble, our mentors are duly occupied with addressing the new affront to progress, while we are temporarily left absolved of the onus of troubleshooting to mind our idle hands. Our collective attention soon fixes on a decommissioned variac which has nobly willed to us its remains for the advancement of our learning.
Meanwhile, Dr. Evans and Dr. Findley work to diagnose the source of inconstancy in the signal they are reading as light impinges upon a photocathode and generates a current through a photomultiplier tube at the terminal point of our endstation. The culprit appears to be our 3 meter normal incidence monochromator (NIM). Its function is to output a chosen wavelength of light for an input of white light, such as that produced by our synchrotron light source, and focus it at a narrow slit approximately 3 meters away. To select for wavelength, a diffraction grating is pivoted about a point on its surface, changing its angle of interaction with the light incident upon it. To adjust focus, the NIM at roughly 8 feet and 1000 lbs in its stainless steel chamber is moved in its behemoth entirety along the path of diffracted light, towards or away from the slit. And to be of use in our study, it must do both repeatably to within a fraction of an angstrom deviation in wavelength. If a single moving component fails to step reproducibly or to return reliably to a desired location, no faith can be placed in the consistency of our data.
Returning to my earlier mention of unique benefits to performing research at CAMD - another is that chores here are often the antithesis of their tedious domestic counterparts. The task at this week's end: filling a nitrogen dewar from a two-story tall nitrogen tank.
The beginning of our third week was spent reviewing lecture notes and web surfing about visualizing 4 dimensional objects (specifically the tesseract), higher dimensions (nth dimension), non-Euclidean spaces, the Twin "Paradox," and zero length vectors.
Jennifer and I also learned how to use AutoCAD and were tasked with drawing part of the endstation on the program.
The second half of the week, we worked on the copper sample cell that was mounted to the end of a cryostat.
The sample cell has been removed in the above picture from the cryostat extension.
A close up of the attached sample cell.
We had to remove the photodiode and various connecting wires before disconnection the sample cell, rearranging, and switching the flanges.
Jennifer and I struggling to get the hex nuts onto the screws to remount the sample cell.
We removed the sample cell from the cryostat to reorient the window to allow the light source to pass through with accordance to our sample chamber. We ran into a stump with the radiation shield so we removed the entire cryostat from the manipulator stand to remove the shield to work with the sample cell.
Dr. Evans and I removing the radiation shield from the cryostat. Jennifer bolting the manipulator to the stand.
Once the shield was removed, it was a lot easier for me to bolt and tighten the sample cell to the end of the cryostat with Jennifer's help.
Jennifer and I using forceps to tighten the nuts of the sample cell. Close up of me working on the sample cell.
The completed and mounted sample cell, ready to be placed in the sample chamber.
Once the sample cell was ready, we leaked checked the various components and removed the blank flange from the sample chamber.
Then came the fun part.
With Dr. Evans in control of the crane, Dr. Findley and I helped maneuver the manipulator to sit onto the sample chamber.
Here comes the crane! Connecting the crane to the manipulator.
Making sure the cryostat extension doesn't hit the stand on the way up. The floating manipulator/cryostat.
Dr. Findley and I positioning the cryostat to be lowered. Fixing the wires so they did not scrape against the walls of the chamber.
After positioning and bolting the manipulator to the top of the sample chamber, we made a saturated solution of sodium salicylate and alcohol and heated the window to evaporate the solvent.
Jennifer watching the sodium salicylate window. A close up of the sodium salicylate layer.
Once the sodium salicylate layer dried on the window, we bolted it to the side of the sample chamber where our measurements would take place. Then we set up the ARS cooling stand next to the sample chamber to connect the tubes. After the ARS was hooked up, Jennifer and I went through the preparations to bake the sample chamber over night.
Dr. Findley attaching the ARS tubes to the cryostat. Jennifer and I putting heat tape, thermocouples,
aluminum on the chamber.
The students participating in this summer's REU experience are:
Ms. Jennifer Hare, Queens College Undergraduate Student, Physics major, Chemistry minor
Ms. Jasmine Nguyen, University of Louisiana at Monroe Undergraduate Student, Biology major with a concentration in Chemical Biology
Ms. Lauren Williams, Hammond High Magnet School
Dr. Cherice M. Evans, Queens College Associate Professor, Department of Chemistry
Dr. Gary L. Findley, University of Louisiana at Monroe Professor, School of Sciences
Dr. Eizi Morikawa, Louisiana State University Center for Advanced Microstructures and Devices (LSU-CAMD)
The pictures presented in this blog are taken by the students or by Dr. Victor Ramirez, LSU-CAMD Research Specialist and may only be used with the permission of Dr. Cherice M. Evans (Queens College) or Dr. Gary L. Findley (University of Louisiana at Monroe).
Our second week at CAMD commences with our continued efforts to bring order to chaos – both of the tropological kind as we attempt to set straight what our faculties have tangled of Dr. Findley’s daily morning lectures, and of the more manifest variety out in the experimental hall.
With our workspace cleared, our attention returns to the alignment and permanent installation of the experimental endstation.
It is imperative that the light reflected from M5, the final mirror of the second tail of the 3m NIM beamline, travel without encumbrance through a gate valve, a sapphire window housed therein, a beam monitoring station consisting of a window and a photodiode –
– and an additional two gate valves before reaching the experimental chamber.
Lest the task sound trivial, let us add the requirement that the light bouncing off of our toroidal mirror be focused at the location of our sample cell inside of the experimental chamber.
Machined to exacting tolerances and plated with gold, the cost of a mirror like M5 can run into the tens of thousands.
A mirror similar to the one aforementioned. Jasmine remains nonchalant to the fact that she cradles the one-time pecuniary equivalent of a private propeller plane.
The NIM beamline features a total of 5 reflective elements between the accelerator ring and our endstation, exclusive of the second tail and the monochromator itself. Each mirror is of a distinct dimension, geometry, and reflectivity specific to its role in funneling light from the point of departure to its destination.
A glimpse of the bendable, cylindrical M2.
Dr. Evans and emeritus research student Kamil Krynski look on as Jasmine delicately adjusts the position of M4.
With the frame of our endstation bolted securely into the concrete floor of the experimental hall, there remains one final undertaking before we can begin the process of evacuating the newly connected chambers: installing a turbopump in the bowels of the structure without offending a cable, thermocouple, or bellows in the process. Fluid teamwork makes up for a lack of contortional ability, and we celebrate our inaugural bake with a Sunday off.
Our first week at CAMD was a short week but just as eventful as our weeks to come. My first day in the facility was Thursday, June 16th and I was overwhelmed with all the laboratory equipment and apparatuses. Dr. Findley and Dr. Evans were more than happy to explain to me the different uses and significance of each piece in our workplace.
A panorama of our endstation of our beamline (on the right) and our work bench (on the left).
Unfortunately, I don’t have any pictures of when we disassembled a turbopump. The turbopump was not pumping to expected pressures and we hypothesized that there was left over oil residue so we took apart the pump to sonicate the turbine blades and any other surface that the residue could have stuck to. After much troubleshooting, fixing the turbopump was beyond our capabilities with our allotted time. Our next task was to position the sample chamber and differential pump in proper alignment with the emitted light from the M5 chamber.
Dr. Evans and Jennifer Hare finding the screws and nuts to bolt the frame of the experimental endstation to the ground.
Bolted Differential Pump stand and Gas Handling System/Sample Chamber (experimental endstation) frame.
We ended the week with re-positioning M5 to where the outgoing light would be focused at the desired point in the sample chamber.
The view of the light from the viewpoint opposite of the entrance window from M5 to the sample chamber.
Before leaving for the weekend, Jennifer and I received a tour of the facility and got to see an aerial view of the storage ring.
This summer will see our group performing research at the Center for Advanced Microstructures and Devices for the first time. The students who will participate in this research and will be active on this blog are Ms. Jennifer Hare, Ms. Jasmine Nguyen and Ms. Lauren Williams.