Lots of (hi-med) Spots

Probably first of two....

In High-Med gas cell looking at focus, it appears we lost way.  After backing out the mirrors and confirming their locations, comparing pumped and really, really pumped gas cell data, and doing more grids than you can shake a stick out, I like echelon/echelle position 22/5.  A couple figures to back up my assertion.

Our data were (in tabular form)

                          ECHELLE TURNS

E               1        2         3         4          5

C    22                            X       X         X 

H    23                            X       X         X

E    24      X                   X        X         X

L    25      X       X 

O   26      X        X         X

The figure above is the FWHM in X and Y as a function of Detector Column for all "roundish" points (see lower right panel) with various cuts.  Upper Right panel is color-coded by Echelon Mirror position.  Upper Left is coded by Echelle Mirror Position.  The yellow points near column 200 and FWHM ~9 pixels look tasty.  I'm not showing other plots that included less rounded spots - this one seems to show the result most clearly.

The two figures above show the sum of "left-center-right" gas cell positions for 22/4, 22/5, 23/4, and 23/5 with the greyscale set to +- 80% of the 99.5%ile value.  The right hand figure shows the residuals for these same echelon/echelle subtracting the fit from the data.  The grey scale is +-50% of the 99.5%ile value established in the left hand figure.

After seeing these points, I asked Curtis to increase our grid.  I'd like it end up as:

                          ECHELLE TURNS

                 1        2         3         4          5         6        7

E      20                                                             O       O

C      21                                                  O        O       O

H      22                            X       X         X        O

E      23                            X       X         X

L      24      X                   X        X         X

O      25      X       X 

N     26      X        X         X

Parts for Gemini/TEXES

This is probably the wrong place for this since this is the EXES online notebook, but I'll set it here for the time being. John and I looked through the TEXES crates for critical components for mounting TEXES to Gemini North in November 2013. I don't know what everything is, but I took pictures of it anyway, so that the people in the know can say, "Oh good, so we still have ____, and it is stored in one of the 3 TEXES crates at the IRTF".

Note:John mentioned buying backup lenses for the achromat. 


a)

 b)

 c) Tommy and I put this under the yellow crate in the storage room. Brackets are zip-tied under the plate.

 d)

 e)

 f) These disks are probably not used and are just different sizes of the parts in i).

 

g) "Gemini Entrance Lens"

h)

 i)

 j)

 k) "April07  Gemini Achromat w/ lenses installed".

Med mode focus

We took some gas cell with rinsed cell spectra on Friday, Feb 8.  We used the pinhole arc to get readings across more of the detector.  We did 2T, 4T, 6T, 8T, 10T, and 12T.  Data were acquired using NSNSNSD.  I analyzed 2-8 using the third N differenced with the first N.  I then differenced charged and rinsed cells to get a series of spots (see clipped picture below from 6 Turns)

The spots with the red crosses were the ones fit with 2D Gaussian.  The results are below.

CLICKFIT on 2D data gives a fit along rows and columns.  In the figure above, the X axis is the column number, so we see the difference in focus caused by the tilted detector.  The different colors are for different turns:  White - 2T; Red - 4T; Green - 6T; Blue - 8T.  The dots are the FWHM along columns and the crosses are for along rows.  As a general rule, the fits along columns (spatial dimension) are generally narrower than the spectral dimension.

I'd say 2T is safely out.  Looking at the spatial, I'd say 6T is closest to where the focus is best near the middle.  This is mostly because 4T and 8T have larger excursions near the ends.  This is a couple turns further out than Curtis found with the odd/even impacted data.  The 6T spectral looks better than the 8T, although I could be convinced that the 8T is more centered.  

I think I'd go with the 6T as our starting point for the High-Med mode.

Quick post on spectra with TAAS

This is out of order, but I wanted to put these images up on the blog.  I'll later work on the blog post about imaging the FCLS and SCHP from TAAS.

The image above is a medium resolution mode spectrum of the FCLS through our 3.5 km/s wide slit.  We were working at near 4.7(?) microns with the N04679 filter, which seemed to be the only one on this run where we had contrast.  There are no lines visible in the image; I haven't extracted a spectrum.  You can see some filter/detector wiggles.  Looks like some vignetting along the slit, too.

The image above shows (top) EXES blackbody in hi-med mode near 4.7(?) microns.  The slit was too long so orders are overlapping.  Signal was very weak; this is the difference between looking at the blackbody and looking at the retro mirror.  At short wavelengths, R=100,000 does keep the signal down.  The bottom image shows the same setup, but looking at the TAAS FCLS.  Ideally, the continuum source would follow the same extent as the blackbody in the top panel, but something seems to be cutting off the FCLS about halfway across the echelon orders.  There are also a few stray reflections that showed up this cooldown - not sure why.

Medium Resolution Spatial Focus CD014

This data is from Jan 15 : data/CD014/cd14_2013jan14: file0-file8.fits.

We had EXES in medium res, pinhole, BP14100 filter, looking out at the gas cell close to the 4th order Q-branch.

We tried turns of 1-7 T on the echelle parabaloid mirror.

Data was analyzed by treating the odd/even effect on rows (dividing each row by its median value), and then using clickfit to measure the Gaussian width across the continuum.

The plot shows the FWHM (in pixels) as one goes left to right on the detector. The number above each curve denotes the number of turns on the echelle mirror.  It seems that 3 has the best centering of the focus shift across the tilted detector, but 4T has a smaller FWHM in the center.  

CTDELAY to frame time

Mark and I mapped frametime as a function of ctdelay.  The scope was connected to the reset pulse.  We were running an ND pattern - during the N frame, there were no reset pulses and during the D there were lots of resets.  We could measure the time on the scope where there were resets pretty accurately.

We had the following data:

CTDELAY          Frame Time
0                           137 msec
5                           273
10                         411
15                         549
25                         827
33                         956
50                         1509
70                         2055

Using CTDELAYMAP.JOU, I did a linear fit to these data.  The 33 ctdelay point was the only one below the fit and the y-intercept for the fit was 130.7 msec, not the 137 msec we got in the data.  Removing the 33 ctdelay point improved things.  I remeasured the 33 ctdelay point and to

33                        1036 msec

Putting this into my fit, I got a nice linear function where:

Frametime = 27.40 msec * ctdelay + 137.1 msec

Solving for ctdelay given a frametime, the relation is:

CTDELAY = ( Frametime [msec] - 137.1 ) / 27.40

Tilted detector distances

With the help of Ryan, we measured the distance/tilt on the tilted detector box, with the bare MUX installed. We used something called a ____. (a non-contact profilometer that uses focus to find planes.)
Below is a drawing, which should make the raw measurement data below superfluous.

Raw measurement data of 4 corners and reference point: 
Point 1: Obox surface

    _____________
    |                              |
    |                              |
    |  __________     |
    |  |5               4|     |
    |  |                   |     |
    |  |                   |     |
    |  |2______  3|     |
    |                                |
    |          1                    |
    |___________ |

Looking from bottom, up

Point 1: reference surface
(X,Y,Z)=(0.97415,-0.92726,0.29984)

Point 2, 3, 4, 5: corners of the detector surface

Point 2:
(X,Y,Z)=(2.11113,1.05580,-0.27409)

Point 3:
(X,Y,Z)=(1.10509,1.04808,-0.27480)

Point 4:
(X,Y,Z)=(1.11233,0.05230,-0.11898)

Point 5:
(X,Y,Z)=(2.11829,0.05939,-0.11827)


2-3 is tilted farther away from O-box
4-5 is tilted closer to O-box