Here is a list of internal MSE memos

No	Topic	Date	Comment
	FOR-MARK	Mar 2009
108	Optimum orientation angle for polarimeters	Sept, 2009	This needs to be examined during the next in-vessel calibration (not for oral exam). Question: can we reduce errors in measuring pitch angle simply by rotating the PEM + linear polarizer assembly?
107	Effect of image size at PEMs	July, 2009
106	PEM offsets and phase shift for FY09 campaign	June, 2009
105	Yet more on MSE thermal shields	March 2009
104	More on MSE thermal shields	Jan 2009
103	Reducing azimuthal temperature variation in the MSE canister	Dec 2008
102	Thermal isolation of lens mount assembly	Nov 2008
101	Allowable thickness of Viton sheet	Nov 2008
100	Simple estimate of canister temperature	Oct 2008
99	Loss of light intensity with a multi-lens solution	Oct 2008
98	Implications of dual-waveplate model for MSE	Oct 2008
97	Thermal resistance analysis for MSE lenses supported by …	Oct 2008
96	Evaluation of SF57 lenses	Oct 2008
95	A simple estimate of requirements for temperature control …	October 2008
94	Proposed solution to MSE stress-induced birefringence	Sept 2008
93	Thermal contact resistance for Viton O-rings	Sept 2008
92	Quantitative estimate of birefringence	October 2008
91	Effect of thermal conductivity of lens ring on temperature …	Sept 2008
90	(superceded by 91)	Sept 2008
89	Time response of a radiative heat shield	August 2008
88	Some considerations in MSE thermal heating	August 2008
87	Optimum angles for measuring birefringence	August 2008
86	Inferring photon count rate from fluctuations in MSE signal	June 2008	Can one estimate the absolute photon rate incident on a detector by looking at the variability in the measured count rate?
85	A simple estimate of the effects of background signal on pitch angles measured by MSE	June 2008	Why we need to be able to compensate the polarized background signal so accurately.
84	Inferring polarization fraction from MSE data	June 2008	How to compute the polarization fraction.
83	Effect of mirror reflections on polarization direction	May 2008	A follow-on to previous memo
82	Polarization changes by flat, ideal mirrors	May 2008	Evaluates potential errors for an in-situ calibration system.
81	Dual waveplates	April 2008	Analysis showing that the fixed phase shift due to mirrors could magnify the effect of variable phase shift due to thermal birefringence.
80	Coordinates for optical calculations	March 2008	A very detailed discussion of the coordinates for optical analysis of MSE.
79	Magnification with two lenses	March 2008
78	Equivalent elliptical mirrors	Mar 2008	More on the possibility of replacing lenses with curved mirrors. This analysis shows what shape elliptical mirror can be used to replace a given lens.
77	Point-to-point imaging for spherical mirrors	Feb 2008	Analysis for Manfred Bitter’s discovery that while one spherical mirror has terrible aberrations, two such mirrors in the appropriate orientation can have excellent focusing.
76	Some calculations on spherical mirrors	Feb 2008	You will remember that one proposed solution to the thermal birefringence problem was to use spherical mirrors.
75	A closer look at MSE harmonics	Jan 2008	More stuff on multiple MSE harmonics.
74	Effect of waveplate on linearly polarized light	Dec 2007	Simple discussion of effect of waveplate on linearly polarized light. Can be used to develop a simple-to-explain model of how MSE works.
73	Effect of small errors in reference sine wave	Oct 2007	What happens if we use the ‘numerical lock-in’ approach and if the PEM frequency drifts a little during a shot. Shows that small drifts in the PEM frequency can be a problem, and for this reason we changed the software to analyze the frequency over a number of piece-wise intervals of 200 ms in the standard mse analysis.
72	withdrawn
71	Design considerations for in-situ reference polarizer	Sept 2007	Title is wrong. This memo discusses expected heating of the MSE optics canister.
70	Inferring retardance from multiple frequencies	August 2007	How to infer the retardance by looking at the ratio of particular frequencies in the MSE spectrum. Howard has a simple discussion of this in his thesis.
69	Computing q from measured pitch angles	July 2007	Have a look at equations 7-8. Previously, students have been asked questions about how to infer q(r=0) from MSE data. See analysis leading up to Eq. 7-8.
68	Intensity of Ha emission from secondary beam neutrals	July 2007
67	<obsolete>
66	Angle transformation from MSE to tokamak coordinates	May 2007
65	Yuh conjecture with rotated neutral beam	April, 2007	This generalizes the analysis of secondary beam emission to allow the beam to be non-normal.
64	Considerations for MSE plasma-sweep calibrations	March, 2007
63	PEM offsets for MSE 2007 calibration	Feb 2007
62	<obsolete>	Feb 2007
61	Ha emission from partially accelerated beam neutrals	Aug 2006
60	<obsolete>
59	<obsolete>
58	Allowable tilt angle of the DNB	May 2006
57	Intensity of Halpha emission from secondary neutrals	May 2006
56	<obsolete>	Dec 2005
55	The Yuh Conjecture	April 2006	A big analysis of the secondary-emission conjecture.
54	A method to compute accurate FFT amplitudes	April 2006
53	Precision of Measured APD frequency response	Feb 2006
52	Considerations for uncooled apertures	Dec 2005
51	Polarization changes by MSE mirrors		What happens to the polarization direction for light that bounces off a mirror? Initially, we thought that the observed heating effect might be caused by the MSE canister deforming, thereby tilting the mirrors. Some mirrors have more effect than others.
50	Effect of spherical aberration on collimating lens in PMT assembly	Dec 2005	For a while, I worried that spherical aberrations in the collimating lens in the APD filter assembly changed the filter passband.
	WGP Polarization angle vs Radius	Oct 2005	J. Ko: lots of data for WGP versus angle
	Effect of finite bit resolution of A/D on MSE Analysis	Oct 2005
	MP436	August 2005	Miniproposal to look for fluorine and molecular emission as background.
	MSE proposal (near-final)	August 2005
	MSE proposal (latest version)	August 2005
-	Revised MSE proposal (uses limiter plasma)	August 2005
-	Draft MSE Mini-proposal	August 2005
-	Considerations on MP to measure Faraday rotation	July 2005
49c	Tilted linear polarizers at oblique angles of incidence	July 2005	J. Ko – a better analysis of the angle-of-incidence effect.
49	Tilted linear polarizers at oblique angles of incidence	June 2005	J. Ko – a better analysis of the angle-of-incidence effect.
48	Linear polarizers at oblique angles of incidence	May 2005	During an in-vessel calibration using the linear polarizer that we could rotate in front of the L1 lens, we noticed that the measured angle depends on the angle of incidence. This memo analyzes the expected behavior. Jinseok has an APS paper on this that goes into detail.
47	More mirror calculations	April 2005	More on proper treatment of imperfect mirrors.
46	Pressure and magnetic field in long pulse DNB	March 2005
45	Considerations on Interlock for the Long Pulse DNB	Feb 2005
42	Effect of Zeeman splitting on MSE analysis	Nov 2004	More on the secondary-emission explanation of beam-into-gas.
41	Elliptically polarized emission	Sept 2004	More on the secondary-emission explanation of beam-into-gas.
40	Computing intensity in e1+e2 direction	Sept 2004	More on the secondary-emission explanation of beam-into-gas.
39	Polarization angle for combined MSE + Zeeman	October 2004	More on the secondary-emission explanation of beam-into-gas.
38	Invessel Verdet measurements	August 2004	We tried to measure the Verdet constant of our lenses in-situ by putting a small amount of current in various EF coils
37	Effect of TF ripple on MSE lens L3	August 2004	Not important.
36	Axial magnetic field from two permanent ring magnets	July 2004	Part of our analysis to measure the Verdet constant of our SFL6 lenses.
35	Calculation of PEM offsets	July 2004	More on analysis of phase shift between PEM drive and the MSE signals at 40 and 44 kHz frequency
34	Analysis of Breton Angles	July 2004	First of series of analyses of the secondary-neutral explanation of beam into gas anomaly.
33	Correcting for circularly polarized light in mse_2020	July 2004	Hmmm, I’m not sure this is correct.
32	The relation between real and MSE invessel optics pitch angles	July 2004	J. Ko
31	To determine the L1 position in (x,y,z) in the MSE coordinate system	July 2004	J. Ko
30	Initial results from In-Vessel MSE calibration	June 2004	First in-vessel calibration, showing cos(2 theta) and cos (4 theta) error terms.
29	Effect of torus pressure on MSE calibration	May 2004	An early attempt to understand the beam-into-gas anomalies.
28	Time Constants and Pressure in DNB Vacuum tank	May 2004
27	Polarizer Calibration of April 28-29	May 2004	First absolute calibration of linear polarizer.
26	Reflections near the Brewster angle	April 2004	More analysis to absolutely calibrate the linear polarizer on the rotational stage.
25	Effect of finite entrance slit on tilted bandpass filters	March 2004	This was a fire drill. For a while, I thought that the filter assemblies yielded a different passband than advertized due to the finite entrance slit. This analysis may be useful when we consider the beam-splitter approach to background subtraction.
24	Analysis of Beam-into-Gas (no TF)	March 2004	Filter temperature scan during beam into gas with no TF. Gives information on the filter performance.
23	More Geometry	March 2004	How to relate the pitch angle in tokamak coordinates to pitch angle in MSE frame of reference. This is also treated (probably in a more understandable way) in Howard’s thesis and Jinseok’s thesis. You should understand this mapping at least at a high level.
22	MSE and Zeeman splitting	Feb 2004	Effect of Zeeman splitting on MSE analysis. Effect is small.
21	Angle of pi radiation in MSE reference frame	Feb 2004	More analysis of imperfect mirrors, including effect of filter temperature scan.
20	Proper treatment of effect of mirrors	Feb 2004	Another in the series that computes the effect of imperfect mirrors on the MSE measured antle
19	Preliminary polarizer calibration results	Jan 2004	First attempt to absolutely calibrate the direction of the transmission axis of the linear polarizer that is mounted on the rotational stage. Accuracy a few hundredth’s of a degree.
18	Linear polarizers and flat glass plates	Jan 2004	Has some interesting stuff on effect of non-normal incidence at PEMs.
17	Angle of pi radiation in MSE frame	Feb 2004	Finally, this memo correctly assumes that sigma and pi light are perpendicular in the MSE frame. The calculation of polarization fraction is still wrong. Some interesting stuff on filter temperature scans at the end.
16	Measuring polarization orientation with crossed polarizers	Nov 2003	unimportant
15	Effect of mixed sigma/pi radiation on MSE analysis	Sept 2003	wrong
14	Thermal Dalpha Emission due to CX on beam ions	August 2003	Some beam neutrals will charge-exchange onto thermal deuterons. The newly-generated thermal neutrals can have 3 à 2 transitions, i.e. Halpha light. The velocity distribution of the thermal neutrals is Maxwellian, with a temperature of maybe 0.1-0.5 keV and so it will be Doppler shifted. Will any of this light get past the MSE filters and thereby pollute the measurement? This memo argues NO.
13	How to compute polarization fraction with background	August 2003	?
12	Line Contributions to MSE Analysis on C-Mod	Feb 2006	First few pages are useful to review for Doppler shift, stark shift, etc. You should understand e.g. figure 3.
11	Effect of mixed sigma/pi radiation	August 2003	This is wrong. the sigma and pi radiation are exactly perpendicular in the MSE frame.
10	New phase offset analysis	July 2003	As you remember, during in-vessel calibration we determine the phase shift between the PEM drive and the MSE signal that maximizes the intensity at various frequencies (40, 44, etc). This memo has the result for the 2003 calibration.
9	Corrected background subtraction	July 2003	Withdrawn.
8	Detailed analysis of MSE spectra	July 2003	Describes the computed intensities at lots of MSE harmonics. See figure 3 for a plot of the expected intensity for ideal mirrors at 40, 44, 42, 46, 38, etc kHz.
7	Is the retardance correct?	June 2003	Followup on memo 5. Not important. But at the end, it does use Mueller calculus to compute the expected behavior of MSE if only one of the two PEMs is turned on. This is the Mueller-approach to the problem we did on the board the other day. I think it gets the same answer.
6	Effect of imperfect mirrors on MSE analysis	June 2003	obsolete
5	Effect of circularly polarized light on MSE analysis	June 2003	We observe that only one of the first-harmonic amplitudes (20 or 22) has a significant amplitude, the other does not. Hawkes concluded that the 20/22 amplitude has info about circular polarization. This memo analyzes the expected behavior. Not important for oral.
4	How to subtract background light	June 2003	3 pg. simply shows that proper way to compensate for the polarized background is to subtract the A40 and A44 amplitudes during beam-off periods from the A40 and A44 amplitudes during beam-on.
3	How to compute MSE polarization fraction	June 2003	Not interesting until after oral exam
2	Effect of polarizer angle on MSE Analysis	June 2003	3 pg. A simple application of Mueller calculus to understanding what happens if the polarizer is not inserted at the same angle in its frame each time.
1	Effect of non-normal PEM incidence	June 2003	Not sure this is right