The test plan presented below was prepared by Brad Wargelin and last updated 25November1997.

SX700 beam (Dec 3-8, Wed 10 pm - Mon 6 am, 80 hours)
 

• find centers of FPC windows
• anode wire aging/gain uniformity
• beam profile/fpc_x2 blocking plate aperture size
• QE mapping
• spectral response function
• counting rate linearity
• gas opacity (optional)
• Backgrounds at various FPC voltage settings

•  HSI uv/ion shield transmission
•  filter transmission
•  polyimide/Al sample transmission
•  window transmission
•  relative aperture sizes

SX700 beam Using SAO end chamber with FPC detector

Pre-pumpdown setup

•  Verify STG programs, make 1 estep = 1 um, limit switch settings, and home programs
•  Align FPCs so stage translations are parallel to window support wires.
•  Find stage positions to approximately center FPCs on beam and record.
•  Destress gas lines by "centering" stages.

•  Check alignment of fpc_hn by finding windowlet centers near ends.
•   Adjust alignment if necessary/possible.
•  Determine center of each FPC using 1dscans (see below).
•  Define aliases for "center_x2", "center_hn", "offcenter_x2"

Find window(let) centers of FPCs  Detector fpc_x2, fpc_hn

• Beam ap  50-um
• Chamber ap none
• FPC ap  37-mm circle on fpc_x2, 100-mm rectangle fpc_hn
• Energy  300 eV --can use a beamline filter to run at high current
• Positions: fpc_x2 center, fpc_hn center, fpc_x2 near fpc_5 4-mm position (14-mm in z)
• Rate  ~5000 Hz, not important, but should be fairly stable
• Find +/- vert and horiz edges of each FPC blocking plate aperture to within 100 um.  Use ratemeter or 1d scans.
• Move to central windowlet.
• Do four 1dscans (17- points, 50- um, 10 sec) about each wire. (This also provides useful info for QE mapping.)
•  Plot up the results and fix the center to within ~30 um.
• Time: (17- pts)(30 sec)(4 wires)(3 positions) = 1.7 hours, beam adjustments, etc.  = 1 hour, Total less than 3 hours

A check of the focal plane FPC (fpc_x2) will be conducted to look for signs of anode aging.  We will also scan fpc_hn for more info on the spatial gain curve. After scans are complete, use a script/program to extract peak and FWHM for each spectrum.  Then plot up peak channel vs. horiz position, and FWHM/peak-ch vs. position, to look for signs of aging.  If any are seen, decide whether or not to avoid the bad spot(s), which may require modification of the test procedures.
 

• Detector fpc_x2, fpc_hn
• Beam ap  50-um
• Chamber ap none
• FPC ap  37-mm circle on fpc_x2, 100-mm rectangle fpc_hn
• Energy  ~1700 eV---can use a beamline filter to run at high current
• Rate  ~5000 Hz, not important, but should be fairly stable
• Counts  ~50000 per point (10 seconds integration plus ~20 sec overhead)
• Command  1dscan
• Positions 37 1-mm horizontal steps for fpc_x2, 50 2-mm horizontal steps for fpc_hn
• Time  (37+50)(30sec)=44min + 16min misc, total approximately 1 hour

Use the edges of the FPC blocking plate aperture(s) to map out the beam profile (vertically and horizontally).  This must be done near the center of a windowlet so window-bowing effects are minimal, i.e., so the only position-dependent effect is beam w.r.t. the aperture edge.
 

• Detector fpc_x2
• Beam ap  50-um
• Chamber ap none
• FPC ap  37-mm circle on fpc_x2, 100-mm rectangle fpc_hn
• Energy  300, 500, 930  (If profile indep of E, then only one E)
• Rate  5000+ Hz
• Counts  1e5 with 100% beam exposure
• Command  1dscans, horiz and vert, ### points, ### increment, ### sec
• Positions Scan 1200 um across horiz and vert blocking plate edges (over windowlet center)
• 31 40-um steps across +hor,-hor,+vert,-vert edges of blocker
• Time  (31 steps)(4 edges)(20+20 sec) = 1.4 hours, setup, etc.    = 0.6 hours , 2 hours per energy, 6 hours for all 3 energies

We will measure the relative QE as a function of position on two FPCs, moving the FPCs behind a fixed aperture, 0.5 mm in diameter.  The effect of window bowing is the primary subject of these tests, and the mapping will be conducted at three energies where window transmission is relatively low.  The supporting wires will be avoided.
 

• Detector fpc_x2, fpc_hn
• Beam ap  50-um
• Chamber ap none
• FPC ap  37-mm circle on fpc_x2, 100-mm rectangle fpc_hn
• Energy  300, 500, 900
• Rate  10000-->2500 Hz (ring current decays)
• Counts  3e5 per point (in center of windowlet)
• Command  listscan, in two dimensions
• Positions fpc_x2 center:
• 5x5 in 0.35-mm steps around center
• plus 3x3+3x5+3x3+5x3+3x3 (57 points)nearby points
• plus 15 other nearby points
• Plus ~20 *center-of-windowlet* points within 37-mm aperture
•   fpc_x2 offcenter (14 mm towards edge):
•       5x3 + 5x5 + 5x3 in 0.35-mm steps
•   fpc_hn:
•       45 *center-of-windowlet* points across half of window
•       plus 6 other points in the other half

• Time:
• fpc_x2 center--( 97 points)(80 sec) = 2.2 hours x 3 energies =  6.6 hrs
• fpc_x2 offcen--( 55 points)(80 sec) = 1.2 hours x 3 energies =  3.6 hrs
• fpc_x2 wincen*--(20 points)(80 sec) = 0.5 hours x 3 energies =  1.5 hrs
• fpc_hn wincen*--(51 points)(80 sec) = 1.1 hours x 3 energies =  3.3 hrs
• subtototal:     15 hours
•   plus 10-minute backgrounds at each energy  1 hr
•   plus ring current adjustments    2 hr
•  Total:            18 hours

Spectral Response Function

Spectra will be collected from monochromatic beams at several energies ranging from <100 eV to 1.7 keV.  Particular attention will be paid to the Ar-L, C-K, N-K, O-K, and Al-K absorption edges.  These tests also give us info on the (relative) QE of the FPC as a function of energy so we need good beam intensity calibration. Also, these tests give us info on pileup---be sure to compare the pileup --- peak with the expected fraction of (0.8e-6)x(rate).  At the least, the pileup fraction should be ~independent of energy (at a given rate).
 

• Detector fpc_x2 (and fpc_hn at the same time)
• Beam aper 600-um
• Chamber aper none
• FPC aper 37-mm circle on fpc_x2, 100-mm rectangle fpc_hn
• Energy: FPCset (xx,xx) means those energies are collected at one FPC voltage
•  78 (60,65,70,75,80,85,90,95),    [8]
•  108 (95,100,105,110,115),      [5]
•  183 (150,183,210)      [3]
•  277 (240,242,244,246,248,250,252,254,256,258,261,264) [12]
•  277 (267,270,273,276,280,284,288,292,296,300,305,310) [12]
•  392 (389,392,395,400,405,410,415,420),   [8]
•  525 (515,520,525,530,535,540,545,550),   [8]
•  each 610,705, 852, 930, 1012, 1254,    [6x1]
•  1487 (1487,1540,1550,1560,1570,1580,1590,1600)  [8]
• 13 FPC voltage settings, 68 energies
• Rate  5000 Hz
• Counts  3e5 per point (60 sec)
• Command  collect
• Horiz/vert One point near/at center
• Time  data collection   68 x  1 min = 1 hour
•   backgrounds/current adjust 13 x 30 min = 6 hours
•   7 hours (8 for both FPCs)

 Counting Rate Linearity
At a few energies, data will be collected for each energy at several widely varying counting rates to determine the accuracy of the pulser deadtime correction method and equations (to ~0.2%).  These tests CANNOT be done on the KMC beam (because relative beam intensity calibration is not accurate enough), but will be done on the white beam with filters. Also, these tests will also give us info on pileup---be sure to plot them up on the spot to see if we need to do more testing.

• Detector fpc_x2, fpc_hn
• Beam aper 600-um
• Chamber aper none
• FPC aper 37-mm circle on fpc_x2, 100-mm rectangle fpc_hn
• Energy  277, 1500 (others?)
• Rate  25000, 20000, 15000, 10000, 5000, 1000 Hz
• X-ray Counts 1e6 per point (60 sec +60 sec overhead)
• Integ time 300 sec at 25000 Hz, 1000 sec at 1000 Hz, 200 sec at others
• Command  collect
• Horiz/vert One point near/at center
• Time  (300+1000+4x200)(2 energies)(2 FPCs) = 2.4 hours
•   4 backgrounds + current adjustments, 3.5 hour
•   6 hours

This test is best conducted on the KMC beam at higher energies, but if we have extra time we may do it on the SX700 at 1.7 keV.  Spectra will be collected at two or more gas pressures (e.g., 400 and 200 torr) and the counting rates (and thus detector QE) compared.

• Detector fpc_x2, fpc_hn
• Beam aper none
• Chamber aper 0.5 mm, <0.5" from FPC
• FPC aper 37-mm circle on fpc_x2, 100-mm rectangle fpc_hn
• Energy  1700
• Rate  5000 Hz
• Pressure 400, 300, 200, 100 torr (Note that the FPC voltage must be reduced at lower  pressures---roughly 100 V per 100 torr.  Voltage must be reduced before the gas pressure!)
• X-ray Counts 1e6 per pressure
• Integ time 200 sec
• Command  collect
• Horiz/vert One point near/at center
• Time  (200 sec)(4 pressures)(2 FPCs)   = 0.5 hours
•   (30 minutes to reduce P and stabilize)(4 P's) = 2 hours
•    Total: 2.5 hours

Wire Reflections

There may be nonnegligible reflections off the window support wires, and this may depend upon energy.  We don't have the proper setup for this on the SX700, however...It is done by measuring relative rates with a wire (no polyimide) in and out of the beam, moving behind a fixed aperture.
 
 
================================================================
SX700 beam Using PTB reflectometer with photodiode detector
================================================================

Window Transmission

The transmission of two demounted FPC windows will be measured at a few points and many energies between 100 and 1800 eV.  The windows will be mounted on a two-axis translation stage in the PTB reflectometer on the SX700 beamline.  Transmission will be measured using in/out tests with a calibrated PTB photodiode as the detector.
 

• Detector photodiode
• Beam aper 600 um  (beam must fall completely within <1.5 mm diameter on window)
• Energy  60, 78, 95, 108, 183, 240-300, 390-415, 515-540, 705, 852, 930, 1012, 1254, 1487, 1545-1570, 1700 eV
•   (Many energies to be added ##############)
• Horiz/vert      One point at center
•   (Note that the central windowlet must be centered on the beam!)
• Time  (#### energies)(3 windows)(2 msmts for in/out)(TBD per msmt)
•    = 100 x TBD
•   HRC/PTB measured ~350 energies in 6 hours
•   plus 2 hours each time to insert and replace the windows

The relative sizes of FPC Aperture Plate apertures up to 70 (TBR ###) microns in diameter will be measured by inserting each aperture into the beam and measuring the signal from a PTB photodiode.  Apertures will be selected by moving them on a two-axis translation stage.  The beam profile will be measured using a 2dscan of the 10-um aperture.  Each aperture must
be "peaked up" = centered on the beam.
 

• Detector photodiode
• Apers to meas. 3,5,7.5,10,15,20,30,40,50,70,100,150,200 um diameter
• Beam aper 600 um?
• Energy  277, 930, 1487 (TBR)
• Horiz/vert One point
• Time  TBD---depends on how many we can fit in reflectometer

Filter Transmission

The transmission of filters to be used during the Absolute QE/White. Beam tests will be measured at several energies.
 

• Detector photodiode
• Filters  3 or 4 TBD
• Beam aper 1200 um?
• Energy  3-8 per filter
• Horiz/vert One point
• Time  TBD---depends on how many we can fit in reflectometer

UV/Ion Shield Transmission

The transmission of the HSI uv/ion shield will be measured at several energies.

• Detector photodiode
• Beam aper 1200 um?
• Energy  60, 78, 95, 108, 183, 240-300, 390-415, 515-540, 705, 852, 930, 1012, 1254, 1487, 1545-1570, 1700 eV
• Horiz/vert One point
• Time  TBD---depends what we can fit in reflectometer

Unstretched aluminized polyimide window material Transmission

The transmission of an unstretched FPC window be measured at several energies.  (maybe?)
 

• Detector photodiode
• Beam aper 1200 um?
• Energy  60, 78, 95, 108, 183, 240-300, 390-415, 515-540, 705, 852, 930, 1012, 1254, 1487, 1545-1570, 1700 eV
• Horiz/vert One point
• Time  TBD---depends what we can fit in reflectometer

This page last updated April 07, 2000