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Procedure of the AC Dipole Measurements

Ryoichi Miyamoto

Last Update 10/21/2008

This note explains how to make measurementswith the Tevatron Vertical AC Dipole Systemfrom the Main Control Room.

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1. Magnet Setup at E17 Service Building

To be safe, go to the E17 servicebuilding and turn off the DCpower supply used in the pingermode.

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• Agilent 33220A (Modulator)– Press Graph.– Press Utility and choose Output Setup. Select High Z for the Load.– Press Arb, and choose Selected Wform and Stored Wforms. Select a waveform whose

name starts with ACD based on the ramp time (The standard is ACD_2321 which means 2k turns of ramp up and down and 3k turns of flattop.). Press Done.

– Change Period, HiLevel, and LoLevel to 168 ms, 5 V, and 0 V for each.– Press Burst and make sure the number of cycles is 1. Press Trigger (in Softkeys) and

change Source to Ext. Make sure the Slope is set to Positive. Press Done.– The output goes to AM(EXT) of SF DS345 and scope. – Press Output.

• SF DS345 (Sine Wave Carrier)– To change frequency and amplitude, press FREQ or AMPL and input the number.– Notice the actual voltage is twice of the number on the display (because the input of the

amplifier has high impedance). • I-T8000 (Amplifier)

– Go to CH1 Sensitivity by pressing Menu/Exit once and Next twice. Make sure RMS Volts is 3.54 and dB Gain is 37.3. Press Menu/Exit.

– It may be safe to apply attenuation when the dipole is not used.• Scope

– Make sure the input impedances for all channels are 1 MΩ.

2. Preparation of Devices

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3. List of Useful AcNet Parameters

The plot shows a list ofuseful AcNet parametersto monitor, during theAC dipole study. Theflying wires can be usedfrom T46.

54. AC Dipole Setup in C9-F0 LAM-11

Change the timing of T:VPNGAD to 1.191 sec. The difference between C:EVTDAX and T:VPNGAD should be 0.01−0.02 sec or 500−1000 rev.

Arm T:VPNGAD to the 4C event.

Switch the magnet to the AC dipole mode (negative polarity, displayed as “A”).

• Set the frequency (T:DS345F) and input voltage (T:DS345A) of the waveform generator. Turn down the voltage to 0.01 V after every excitations.• See the tables in pages 9 & 10 for the relation among the frequency, driving tune, input voltage, and oscillation amplitude.• The voltage and frequency are adjusted by 0.01 V and 0.01 Hz. Be careful that the frequency is in “Hz”, not in “kHz”.• No change for the parameters of the AC dipole’s ramp: T:HP332A and T:HP332F.

Enable T:VPNGAD.

After a study, set the parameters to the original values.

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5. Data Acquisition with T42

Data acquisition is done from“Data” page.

Choose the BPM’s to be used.Note that acquiring all the BPMdata takes about 4.5 min. Just fora testing, use a small number ofBPM’s.

For “Trigger Selection”, choose“New Triggered Data Only, No Kick”.

Make sure that the kicking isdisabled and plotting is enabled.

“Get Data” starts the acquisition.

Reboot T42 in each measurement.

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After the data acquisition, T42 automatically plots TBT data.

We can change the BPM.

6. Data Check with T42

We can plot the TBT or tune.

We can change the axes ranges.

Select “Plot” for re-plotting.

An example

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7. Data Saving with T42

BPM’s data can be saved from the“Write” page.

I usually disable the “header” and “status” information.

My Mathematica codes readhorizontal and vertical dataseparately. The unit should be“millimeters”.

Intensity may not be necessary.

“Write” uploads text files into adirectory under

http://www-bd.fnal.gov/userb/tevatron/tbt/

The name of the directory isyymmdd_time, 080930_1411 inthis case.

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8. Table for 150 GeVδd νd fac [Hz] Iac / Vin [mho] Vin,max [V] Iac,max [A] Δyarc / Vin [mm / V] Δyarc,max [mm]

-0.040 0.538 22043.0369811 90 2.50 224 0.75 1.87

-0.035 0.543 21804.4759749 97 2.58 254 0.93 2.42

-0.030 0.548 21565.9149686 106 2.67 290 1.18 3.22

-0.025 0.553 21327.3539623 106 2.98 321 1.41 4.29

-0.020 0.558 21088.7929560 101 3.36 351 1.68 5.85

-0.015 0.563 20850.2319497 93 3.83 369 2.07 8.19

-0.010 0.568 20611.6709434 83 4.35 379 2.78 12.64

-0.005 0.573 20373.1099371 75 4.88 385 5.01 25.67

0.000 0.578 20134.5489308 68 5.40 387    

0.005 0.583 19895.9879245 62 5.72 374 4.11 24.95

0.010 0.588 19657.4269183 56 5.80 343 1.88 11.43

0.015 0.593 19418.8659120 52 5.80 315 1.16 7.00

0.020 0.598 19180.3049057 49 5.80 294 0.82 4.90

0.025 0.603 18941.7438994 46 5.80 274 0.62 3.66

0.030 0.608 18703.1828931 44 5.80 259 0.49 2.88

0.035 0.613 18464.6218868 42 5.80 244 0.40 2.33

0.040 0.618 18226.0608805 40 5.80 234 0.33 1.95

Note: the revolution frequency at 150 GeV is 47.7122012579 kHz.

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9. Table for 980 GeVδd νd fac [Hz] Iac / Vin [mho] Vin,max [V] Iac,max [A] Δyarc / Vin [mm / V] Δyarc,max [mm]

-0.040 0.538 22043.4549811 90 2.50 224 0.11 0.29

-0.035 0.543 21804.8894510 97 2.58 254 0.14 0.37

-0.030 0.548 21566.3239209 106 2.67 290 0.18 0.49

-0.025 0.553 21327.7583909 106 2.98 321 0.22 0.66

-0.020 0.558 21089.1928608 101 3.36 351 0.26 0.90

-0.015 0.563 20850.6273307 93 3.83 369 0.32 1.25

-0.010 0.568 20612.0618006 83 4.35 379 0.43 1.93

-0.005 0.573 20373.4962705 75 4.88 385 0.77 3.93

0.000 0.578 20134.9307404 68 5.40 387    

0.005 0.583 19896.3652103 62 5.72 374 0.63 3.82

0.010 0.588 19657.7996802 56 5.80 343 0.29 1.75

0.015 0.593 19419.2341501 52 5.80 315 0.18 1.07

0.020 0.598 19180.6686200 49 5.80 294 0.13 0.75

0.025 0.603 18942.1030899 46 5.80 274 0.09 0.56

0.030 0.608 18703.5375598 44 5.80 259 0.07 0.44

0.035 0.613 18464.9720297 42 5.80 244 0.06 0.36

0.040 0.618 18226.4064996 40 5.80 234 0.05 0.30

Note: the revolution frequency at 980 GeV is 47.7131060198 kHz.