# Presentation: 678952

## Week in Review: 08/18/03 – 08/25/03

**  ****Doug Moehs – FNAL**

- Officially reached **225** pb-1 for fiscal year 2003 on Friday just before 7:00 during store 2934!!

- All Experimenters' Mtg - Aug. 25, 2003

## Stores Summary

| Store | Initial
Lum.
(E30) | Deliv’d
Lum. (nb-1) | Termination | Time
(hr) | Stack/
Unstack
(mA) | Comments |
| --- | --- | --- | --- | --- | --- | --- |
| 2923 | 40.5 | 581 | Quench | 5.2 | 140/120 | KAMAC Power Supply |
| 2928 | 42.2 | 65 | Quench | 0.5 | 137/110 | Separator spark  |
| 2932 | 27.6 | 983  | Intentional  | 18.6  | 120  |   L. Damper on/ new limiter
54% Pbar eff. to HEP  
M:Q205 off, emit. Growth |
| 2934 | 40.0 | 1665  | Intentional  | 23 | 134/123 | Lost RF3 during store
Reached 225 pb-1  |
| 2937 | 41.4 | 1528  |  Intentional | 19 | 130/118  | Delayed due to lost stack
Power glitch  |
| 2939 | 41.7  |  1531 | Intentional  | 18.2  | 169/154  |  56.7% to HEP, losses up ramp |
| 2941  | 40.0  | 934  | Quench  | 10.5  | 150/137   | Power glitch   |

- Doug Moehs (John 17:3)

- All Experimenters' Mtg - Aug. 25, 2003

**Notes:**
Short store lifetimes due to different failures.

## Slide 3

- Doug Moehs (John 17:3)

- All Experimenters' Mtg - Aug. 25, 2003

## Plot made by David Mcginnis

- Doug Moehs (John 17:3)

- All Experimenters' Mtg - Aug. 25, 2003

## Plot made by David Mcginnis

- Doug Moehs (John 17:3)

- All Experimenters' Mtg - Aug. 25, 2003

**Notes:**
Lower efficiency during teV acceleration.

## TeV Studies and Changes

- Looking for the cause of losses
- Parsed the squeeze with coalesced beam (12x0) to look at B11 losses
- Losses may be associated with beam-beam effects?
- Longitudinal Dampers turned back on and tested with 12x0
- A new phase limiter was installed in the high level RF
- Adjusting the MI flattop energy on Pbar cycles
- Energy change in steps of 10 MeV on 2A’s
- 20 MeV reduction made so far, started on store 2934
- Preparation of a new helix using more separators up the ramp.
- Looked at aperture at A0 on both helixes
- 36x4 will be attempted again this week
- Lattice measurements
- Optics measurements and corrections

- Doug Moehs (John 17:3)

- All Experimenters' Mtg - Aug. 25, 2003

**Notes:**
14:51:42 Mon Aug 18 2003- Parse of squeeze to look at B11 losses; B11 orbit bumps --
summary of changes made during the 12x0 store. Basically we lowered the beam position at B11 vertically, raised the vertical tune and made SQ more positive. 

12:07:58 Tue Aug 19 2003 
Using uncoalesced beam the studies looked at aperture at A0 on both helixes. The scans maxed out the orbit bumps in both helixes ie no aperture problem was found at A0 

We have beam at 150. We are waiting to hear from John Reid who is installing the phase limiter in the rf high level so that the longitudinal damper can be put back in use. - bh-- Wed Aug 20 12:02:47 comment by...bh --  The longitudinal damper is reconnected and has been tested at 150. We will turn it on for the 12x0 store. 

## Machine Updates 

- Proton Source
- We have 2 spares 7835 tubes but we still owe 2 tubes to BNL and 1 to Argonne
- Recycler
- Longitudinal emittance evolution with MI Ramp correction
- MI Ramp deflections of 0.25 mm Horizontal and 0.1 mm Vertical observed
- Main Injector
- Slip stacking
- Beam loading and transition losses
- NUMI multi-batch acceleration
- Without Booster cogging:  limit number of study pulses
- 2.5MHz acceleration
- Tune and orbit measurements
- Antiproton Source
- New scheme: limit the number of bunches extracted by longitudinal emittance
- Prevents unstacking more bunches than the MI can reasonably coalesce

- Doug Moehs (John 17:3)

- All Experimenters' Mtg - Aug. 25, 2003

**Notes:**
Good Morning-
            Last night a modified scheme for controlling the longitudinal emittance of Pbars being unstacked was tested and implemented in the Sequencer. A new VSA marker mode, A:VSAMRK = 7, now exists which compares the calculated longitudinal emittance to be unstacked on a given shot, A:RCBKAM,  with a predetermined limit set by A:VSALER. If RCBKAM is > than VSALER, the VSA adjusts the markers until RCBKAM is less than VSALER. In this way, we hope to prevent sending more 53 MHz bunches to the MI than it can reasonably coalesce. Currently A:VSALER is set to 1.3 which should limit the maximum number of bunches to 11 or 12. Normally, this new mode should intervene only on shots 8 and 9 if most of the stack is being used. When active, this mode will limit the intensity of the pbars being unstacked in order to maintain the desired longitudinal emittance, so don’t be surprised if fewer pbars are unstacked than requested. A:VSAEXI will display the expected intensity to be unstacked. Refer to the shot scrapbook entry for store 2923 to see some particulars.
            As always, I’m available to answer questions. Thanks to Dave McGinnis for making the code change.
Regards,
Elvin 

## This Weeks Focus:  Studies 

- Commission new Helix 36x4 and hopefully 36x36
- Possible destructive in that there could be a quench
- Access into all tunnels on Thursday for 8 hours
- Dedicated studies:
- Pbar
- Main Injector
- Recycler
- Booster (during the Thursday shutdown)
- Stack and Store through Labor Day weekend
- MI and SY120 Semi-parasitic studies
- 10% of time line, 20% after stack reaches 120 mA

- Doug Moehs (John 17:3)

- All Experimenters' Mtg - Aug. 25, 2003

**Notes:**
New helix commissioning may be destructive in the sense that there could be a quench

- Schedule by Bob Mau

- Doug Moehs (John 17:3)

- All Experimenters' Mtg - Aug. 25, 2003

## Brief Summary

- Since Wednesday we have had several long stores
- Lifted administrative control on unstacking 110 mA
- Originally applied due to short stores
- All average initial luminosities > 40e30cm-2s-1 with the exception of store 2932.
- >>70 store hours
- Focus for this week
- Helix commissioning
- 8 hour access
- Integrate luminosity were possible: the schedule will flex to accommodate studies.

- Doug Moehs (John 17:3)

- All Experimenters' Mtg - Aug. 25, 2003